wpf 2007-10-26 15:01
WPF中如何实现数据与表示分离。（二） —— Binding（上）
还是用ColorPicker来作为例子。现在我们需要将它的数据层和表示层进行划分。在这个例子中，数据层的业务逻辑很简单：能够根据给入的三个变量生成一个颜色值。如果将它描述为一个对象，可能是下面的结构。
[size=13px][color=#008080] 1[/color][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/None.gif[/img]
[color=#0000ff]public[/color]
[color=#0000ff]class[/color][color=#000000] ColorPickerData
[/color][color=#008080] 2[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/ExpandedBlockStart.gif[/img][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/ContractedBlock.gif[/img] [/color][img=15,20]http://www.cnblogs.com/Images/dot.gif[/img][color=#000000]{
[/color][color=#008080] 3[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif[/img] [/color][color=#0000ff]public[/color][color=#000000] ColorPickerData()
[/color][color=#008080] 4[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif[/img][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/ContractedSubBlock.gif[/img] [/color][img=15,20]http://www.cnblogs.com/Images/dot.gif[/img][color=#000000]{ }[/color]
[color=#008080] 5[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif[/img]
[/color][color=#008080] 6[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif[/img] [/color][color=#0000ff]byte[/color][color=#000000] _red;
[/color][color=#008080] 7[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif[/img] [/color][color=#0000ff]byte[/color][color=#000000] _green;
[/color][color=#008080] 8[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif[/img] [/color][color=#0000ff]byte[/color][color=#000000] _blue;
[/color][color=#008080] 9[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif[/img] Brush _backgound;
[/color][color=#008080]10[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif[/img]
[/color][color=#008080]11[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif[/img] [/color][color=#0000ff]public[/color]
[color=#0000ff]byte[/color][color=#000000] Red
[/color][color=#008080]12[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif[/img][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/ContractedSubBlock.gif[/img] [/color][img=15,20]http://www.cnblogs.com/Images/dot.gif[/img][color=#000000]{
[/color][color=#008080]13[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif[/img][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/ContractedSubBlock.gif[/img] [/color][color=#0000ff]get[/color]
[img=15,20]http://www.cnblogs.com/Images/dot.gif[/img][color=#000000]{ [/color][color=#0000ff]return[/color]
[color=#0000ff]this[/color][color=#000000]._red; }[/color]
[color=#008080]14[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif[/img] [/color][color=#0000ff]set[/color]
[color=#008080]15[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif[/img][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/ContractedSubBlock.gif[/img] [/color][img=15,20]http://www.cnblogs.com/Images/dot.gif[/img][color=#000000]{
[/color][color=#008080]16[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif[/img] [/color][color=#0000ff]this[/color][color=#000000]._red [/color][color=#000000]=[/color][color=#000000] value;
[/color][color=#008080]17[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif[/img] OnValueChanged();
[/color][color=#008080]18[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif[/img] }[/color]
[color=#008080]19[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif[/img] }[/color]
[color=#008080]20[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif[/img] [/color][color=#0000ff]public[/color]
[color=#0000ff]byte[/color][color=#000000] Green
[/color][color=#008080]21[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif[/img][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/ContractedSubBlock.gif[/img] [/color][img=15,20]http://www.cnblogs.com/Images/dot.gif[/img][color=#000000]{
[/color][color=#008080]22[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif[/img][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/ContractedSubBlock.gif[/img] [/color][color=#0000ff]get[/color]
[img=15,20]http://www.cnblogs.com/Images/dot.gif[/img][color=#000000]{ [/color][color=#0000ff]return[/color]
[color=#0000ff]this[/color][color=#000000]._green; }[/color]
[color=#008080]23[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif[/img] [/color][color=#0000ff]set[/color]
[color=#008080]24[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif[/img][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/ContractedSubBlock.gif[/img] [/color][img=15,20]http://www.cnblogs.com/Images/dot.gif[/img][color=#000000]{
[/color][color=#008080]25[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif[/img] [/color][color=#0000ff]this[/color][color=#000000]._green [/color][color=#000000]=[/color][color=#000000] value;
[/color][color=#008080]26[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif[/img] OnValueChanged();
[/color][color=#008080]27[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif[/img] }[/color]
[color=#008080]28[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif[/img] }[/color]
[color=#008080]29[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif[/img] [/color][color=#0000ff]public[/color]
[color=#0000ff]byte[/color][color=#000000] Blue
[/color][color=#008080]30[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif[/img][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/ContractedSubBlock.gif[/img] [/color][img=15,20]http://www.cnblogs.com/Images/dot.gif[/img][color=#000000]{
[/color][color=#008080]31[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif[/img][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/ContractedSubBlock.gif[/img] [/color][color=#0000ff]get[/color]
[img=15,20]http://www.cnblogs.com/Images/dot.gif[/img][color=#000000]{ [/color][color=#0000ff]return[/color]
[color=#0000ff]this[/color][color=#000000]._blue; }[/color]
[color=#008080]32[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif[/img] [/color][color=#0000ff]set[/color]
[color=#008080]33[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif[/img][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/ContractedSubBlock.gif[/img] [/color][img=15,20]http://www.cnblogs.com/Images/dot.gif[/img][color=#000000]{
[/color][color=#008080]34[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif[/img] [/color][color=#0000ff]this[/color][color=#000000]._blue [/color][color=#000000]=[/color][color=#000000] value;
[/color][color=#008080]35[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif[/img] OnValueChanged();
[/color][color=#008080]36[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif[/img] }[/color]
[color=#008080]37[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif[/img] }[/color]
[color=#008080]38[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif[/img] [/color][color=#0000ff]public[/color][color=#000000] Brush Background
[/color][color=#008080]39[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif[/img][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/ContractedSubBlock.gif[/img] [/color][img=15,20]http://www.cnblogs.com/Images/dot.gif[/img][color=#000000]{
[/color][color=#008080]40[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif[/img][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/ContractedSubBlock.gif[/img] [/color][color=#0000ff]get[/color]
[img=15,20]http://www.cnblogs.com/Images/dot.gif[/img][color=#000000]{ [/color][color=#0000ff]return[/color]
[color=#0000ff]this[/color][color=#000000]._backgound; }[/color]
[color=#008080]41[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif[/img][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/ContractedSubBlock.gif[/img] [/color][color=#0000ff]set[/color]
[img=15,20]http://www.cnblogs.com/Images/dot.gif[/img][color=#000000]{ [/color][color=#0000ff]this[/color][color=#000000]._backgound [/color][color=#000000]=[/color][color=#000000] value; }[/color]
[color=#008080]42[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif[/img] }[/color]
[color=#008080]43[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif[/img]
[/color][color=#008080]44[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif[/img] [/color][color=#0000ff]private[/color]
[color=#0000ff]void[/color][color=#000000] OnValueChanged()
[/color][color=#008080]45[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif[/img][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/ContractedSubBlock.gif[/img] [/color][img=15,20]http://www.cnblogs.com/Images/dot.gif[/img][color=#000000]{
[/color][color=#008080]46[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif[/img] [/color][color=#0000ff]this[/color][color=#000000]._backgound [/color][color=#000000]=[/color]
[color=#0000ff]new[/color][color=#000000] SolidColorBrush(Color.FromRgb([/color][color=#0000ff]this[/color][color=#000000]._red, [/color][color=#0000ff]this[/color][color=#000000]._green, [/color][color=#0000ff]this[/color][color=#000000]._blue));
[/color][color=#008080]47[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif[/img] }[/color]
[color=#008080]48[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/ExpandedBlockEnd.gif[/img] }[/color]
[color=#008080]49[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/None.gif[/img][/color] [/size]
[size=8pt]（注意：以上代码仅为说明问题。对于实现方式，大家应该都有更好的想法。）[/size]
然后表示层通过一定的途径将这些信息展示出来。
于是，我们编写了如下的展示层XAML文件，试图让它能够很好的展示这个数据对象。
[size=13px][color=#008080] 1[/color][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/None.gif[/img][color=#0000ff]<[/color][color=#800000]Window [/color][color=#ff0000]x:Class[/color][color=#0000ff]="ColorPicker2.Window1"[/color]
[color=#008080] 2[/color][color=#ff0000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/None.gif[/img] xmlns[/color][color=#0000ff]="http://schemas.microsoft.com/winfx/avalon/2005"[/color]
[color=#008080] 3[/color][color=#ff0000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/None.gif[/img] xmlns:x[/color][color=#0000ff]="http://schemas.microsoft.com/winfx/xaml/2005"[/color]
[color=#008080] 4[/color][color=#ff0000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/None.gif[/img] Title[/color][color=#0000ff]="ColorPicker2"[/color]
[color=#008080] 5[/color][color=#ff0000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/None.gif[/img] Height[/color][color=#0000ff]="130"[/color][color=#ff0000] Width[/color][color=#0000ff]="300"[/color]
[color=#008080] 6[/color][color=#ff0000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/None.gif[/img] [/color][color=#0000ff]>[/color]
[color=#008080] 7[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/None.gif[/img] [/color][color=#0000ff]<[/color][color=#800000]Grid[/color][color=#0000ff]>[/color]
[color=#008080] 8[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/None.gif[/img] [/color][color=#0000ff]<[/color][color=#800000]Grid[/color][color=#ff0000].RowDefinitions[/color][color=#0000ff]>[/color]
[color=#008080] 9[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/None.gif[/img] [/color][color=#0000ff]<[/color][color=#800000]RowDefinition[/color][color=#0000ff]/>[/color]
[color=#008080]10[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/None.gif[/img] [/color][color=#0000ff]<[/color][color=#800000]RowDefinition[/color][color=#0000ff]/>[/color]
[color=#008080]11[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/None.gif[/img] [/color][color=#0000ff]<[/color][color=#800000]RowDefinition[/color][color=#0000ff]/>[/color]
[color=#008080]12[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/None.gif[/img] [/color][color=#0000ff]</[/color][color=#800000]Grid.RowDefinitions[/color][color=#0000ff]>[/color]
[color=#008080]13[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/None.gif[/img] [/color][color=#0000ff]<[/color][color=#800000]Grid[/color][color=#ff0000].ColumnDefinitions[/color][color=#0000ff]>[/color]
[color=#008080]14[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/None.gif[/img] [/color][color=#0000ff]<[/color][color=#800000]ColumnDefinition [/color][color=#ff0000]Width[/color][color=#0000ff]="40"[/color][color=#0000ff]/>[/color]
[color=#008080]15[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/None.gif[/img] [/color][color=#0000ff]<[/color][color=#800000]ColumnDefinition [/color][color=#ff0000]Width[/color][color=#0000ff]="150"[/color][color=#0000ff]/>[/color]
[color=#008080]16[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/None.gif[/img] [/color][color=#0000ff]<[/color][color=#800000]ColumnDefinition[/color][color=#0000ff]/>[/color]
[color=#008080]17[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/None.gif[/img] [/color][color=#0000ff]</[/color][color=#800000]Grid.ColumnDefinitions[/color][color=#0000ff]>[/color]
[color=#008080]18[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/None.gif[/img]
[/color][color=#008080]19[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/None.gif[/img] [/color][color=#0000ff]<[/color][color=#800000]TextBlock [/color][color=#ff0000]Grid.Column[/color][color=#0000ff]="0"[/color][color=#ff0000] Grid.Row[/color][color=#0000ff]="0"[/color][color=#0000ff]>[/color][color=#000000]Red:[/color][color=#0000ff]</[/color][color=#800000]TextBlock[/color][color=#0000ff]>[/color]
[color=#008080]20[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/None.gif[/img] [/color][color=#0000ff]<[/color][color=#800000]Slider [/color][color=#ff0000]Grid.Column[/color][color=#0000ff]="1"[/color][color=#ff0000] Grid.Row[/color][color=#0000ff]="0"[/color]
[color=#008080]21[/color][color=#ff0000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/None.gif[/img] Minimum[/color][color=#0000ff]="0"[/color][color=#ff0000] Maximum[/color][color=#0000ff]="255"[/color][color=#0000ff]/>[/color]
[color=#008080]22[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/None.gif[/img]
[/color][color=#008080]23[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/None.gif[/img] [/color][color=#0000ff]<[/color][color=#800000]TextBlock [/color][color=#ff0000]Grid.Column[/color][color=#0000ff]="0"[/color][color=#ff0000] Grid.Row[/color][color=#0000ff]="1"[/color][color=#0000ff]>[/color][color=#000000]Green:[/color][color=#0000ff]</[/color][color=#800000]TextBlock[/color][color=#0000ff]>[/color]
[color=#008080]24[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/None.gif[/img] [/color][color=#0000ff]<[/color][color=#800000]Slider [/color][color=#ff0000]Grid.Column[/color][color=#0000ff]="1"[/color][color=#ff0000] Grid.Row[/color][color=#0000ff]="1"[/color]
[color=#008080]25[/color][color=#ff0000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/None.gif[/img] Minimum[/color][color=#0000ff]="0"[/color][color=#ff0000] Maximum[/color][color=#0000ff]="255"[/color][color=#0000ff]/>[/color]
[color=#008080]26[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/None.gif[/img]
[/color][color=#008080]27[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/None.gif[/img] [/color][color=#0000ff]<[/color][color=#800000]TextBlock [/color][color=#ff0000]Grid.Column[/color][color=#0000ff]="0"[/color][color=#ff0000] Grid.Row[/color][color=#0000ff]="2"[/color][color=#0000ff]>[/color][color=#000000]Blue:[/color][color=#0000ff]</[/color][color=#800000]TextBlock[/color][color=#0000ff]>[/color]
[color=#008080]28[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/None.gif[/img] [/color][color=#0000ff]<[/color][color=#800000]Slider [/color][color=#ff0000]Grid.Column[/color][color=#0000ff]="1"[/color][color=#ff0000] Grid.Row[/color][color=#0000ff]="2"[/color]
[color=#008080]29[/color][color=#ff0000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/None.gif[/img] Minimum[/color][color=#0000ff]="0"[/color][color=#ff0000] Maximum[/color][color=#0000ff]="255"[/color][color=#0000ff]/>[/color]
[color=#008080]30[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/None.gif[/img]
[/color][color=#008080]31[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/None.gif[/img] [/color][color=#0000ff]<[/color][color=#800000]Border [/color][color=#ff0000]Grid.Column[/color][color=#0000ff]="2"[/color][color=#ff0000] Grid.Row[/color][color=#0000ff]="0"[/color][color=#ff0000] Grid.RowSpan[/color][color=#0000ff]="3"[/color][color=#ff0000] Margin[/color][color=#0000ff]="5,5,5,5"[/color][color=#0000ff]>[/color]
[color=#008080]32[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/None.gif[/img] [/color][color=#0000ff]<[/color][color=#800000]Border [/color][color=#ff0000]BorderThickness[/color][color=#0000ff]="1"[/color][color=#ff0000] CornerRadius[/color][color=#0000ff]="5"[/color][color=#ff0000] BorderBrush[/color][color=#0000ff]="Gray"[/color][color=#0000ff]/>[/color]
[color=#008080]33[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/None.gif[/img] [/color][color=#0000ff]</[/color][color=#800000]Border[/color][color=#0000ff]>[/color]
[color=#008080]34[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/None.gif[/img] [/color][color=#0000ff]</[/color][color=#800000]Grid[/color][color=#0000ff]>[/color]
[color=#008080]35[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/None.gif[/img][/color][color=#0000ff]</[/color][color=#800000]Window[/color][color=#0000ff]>[/color] [/size]
现在，看起来结构更加清晰一些了。但是，我们如何让数据层和表示层进行衔接呢？往往这些衔接的逻辑可能会使我们系统的层次界限变得模糊。最终变成了铁板一块。
我们来看一下在WPF中是如何实现这种衔接的。下面的是完整的数据展示层XAML。
[size=13px][color=#008080] 1[/color][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/None.gif[/img][color=#0000ff]<?[/color][color=#ff00ff]Mapping XmlNamespace="local" ClrNamespace="ColorPicker2"[/color][color=#0000ff]?>[/color]
[color=#008080] 2[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/None.gif[/img][/color][color=#0000ff]<[/color][color=#800000]Window [/color][color=#ff0000]x:Class[/color][color=#0000ff]="ColorPicker2.Window1"[/color]
[color=#008080] 3[/color][color=#ff0000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/None.gif[/img] xmlns[/color][color=#0000ff]="http://schemas.microsoft.com/winfx/avalon/2005"[/color]
[color=#008080] 4[/color][color=#ff0000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/None.gif[/img] xmlns:x[/color][color=#0000ff]="http://schemas.microsoft.com/winfx/xaml/2005"[/color]
[color=#008080] 5[/color][color=#ff0000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/None.gif[/img] xmlns:l[/color][color=#0000ff]="local"[/color]
[color=#008080] 6[/color][color=#ff0000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/None.gif[/img] Title[/color][color=#0000ff]="ColorPicker2"[/color]
[color=#008080] 7[/color][color=#ff0000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/None.gif[/img] Height[/color][color=#0000ff]="130"[/color][color=#ff0000] Width[/color][color=#0000ff]="300"[/color]
[color=#008080] 8[/color][color=#ff0000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/None.gif[/img] [/color][color=#0000ff]>[/color]
[color=#008080] 9[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/None.gif[/img] [/color][color=#0000ff]<[/color][color=#800000]Grid[/color][color=#0000ff]>[/color]
[color=#008080]10[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/None.gif[/img] [/color][color=#0000ff][color=#0000ff]<[/color][color=#800000]Grid[/color][color=#ff0000].Resources[/color][color=#0000ff]>[/color]
[/color][color=#008080]11[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/None.gif[/img] [/color][color=#0000ff][color=#0000ff]<[/color][color=#800000]l:ColorPickerData [/color][color=#ff0000]x:Key[/color][color=#0000ff]="colorPickerData"[/color][color=#0000ff]/>[/color]
[/color][color=#008080]12[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/None.gif[/img]
[color=#0000ff]</[/color][color=#800000]Grid.Resources[/color][color=#0000ff]>[/color]
[/color][color=#008080]13[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/None.gif[/img]
[color=#0000ff]<[/color][color=#800000]Grid[/color][color=#ff0000].DataContext[/color][color=#0000ff]>[/color]
[/color][color=#008080]14[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/None.gif[/img] [/color][color=#0000ff][color=#0000ff]<[/color][color=#800000]Binding [/color][color=#ff0000]Source[/color][color=#0000ff]="{StaticResource colorPickerData}"[/color][color=#0000ff]/>[/color]
[/color][color=#008080]15[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/None.gif[/img] [/color][color=#0000ff][color=#0000ff]</[/color][color=#800000]Grid.DataContext[/color][color=#0000ff]>[/color]
[/color][color=#008080]16[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/None.gif[/img] [/color][color=#0000ff]<[/color][color=#800000]Grid[/color][color=#ff0000].RowDefinitions[/color][color=#0000ff]>[/color]
[color=#008080]17[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/None.gif[/img] [/color][color=#0000ff]<[/color][color=#800000]RowDefinition[/color][color=#0000ff]/>[/color]
[color=#008080]18[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/None.gif[/img] [/color][color=#0000ff]<[/color][color=#800000]RowDefinition[/color][color=#0000ff]/>[/color]
[color=#008080]19[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/None.gif[/img] [/color][color=#0000ff]<[/color][color=#800000]RowDefinition[/color][color=#0000ff]/>[/color]
[color=#008080]20[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/None.gif[/img] [/color][color=#0000ff]</[/color][color=#800000]Grid.RowDefinitions[/color][color=#0000ff]>[/color]
[color=#008080]21[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/None.gif[/img] [/color][color=#0000ff]<[/color][color=#800000]Grid[/color][color=#ff0000].ColumnDefinitions[/color][color=#0000ff]>[/color]
[color=#008080]22[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/None.gif[/img] [/color][color=#0000ff]<[/color][color=#800000]ColumnDefinition [/color][color=#ff0000]Width[/color][color=#0000ff]="40"[/color][color=#0000ff]/>[/color]
[color=#008080]23[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/None.gif[/img] [/color][color=#0000ff]<[/color][color=#800000]ColumnDefinition [/color][color=#ff0000]Width[/color][color=#0000ff]="150"[/color][color=#0000ff]/>[/color]
[color=#008080]24[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/None.gif[/img] [/color][color=#0000ff]<[/color][color=#800000]ColumnDefinition[/color][color=#0000ff]/>[/color]
[color=#008080]25[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/None.gif[/img] [/color][color=#0000ff]</[/color][color=#800000]Grid.ColumnDefinitions[/color][color=#0000ff]>[/color]
[color=#008080]26[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/None.gif[/img]
[/color][color=#008080]27[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/None.gif[/img] [/color][color=#0000ff]<[/color][color=#800000]TextBlock [/color][color=#ff0000]Grid.Column[/color][color=#0000ff]="0"[/color][color=#ff0000] Grid.Row[/color][color=#0000ff]="0"[/color][color=#0000ff]>[/color][color=#000000]Red:[/color][color=#0000ff]</[/color][color=#800000]TextBlock[/color][color=#0000ff]>[/color]
[color=#008080]28[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/None.gif[/img] [/color][color=#0000ff]<[/color][color=#800000]Slider [/color][color=#ff0000]Grid.Column[/color][color=#0000ff]="1"[/color][color=#ff0000] Grid.Row[/color][color=#0000ff]="0"[/color]
[color=#008080]29[/color][color=#ff0000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/None.gif[/img] Minimum[/color][color=#0000ff]="0"[/color][color=#ff0000] Maximum[/color][color=#0000ff]="255"[/color][color=#ff0000] [color=#ff0000]Value[/color][color=#0000ff]="{Binding Path=Red}"[/color][/color][color=#0000ff]/>[/color]
[color=#008080]30[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/None.gif[/img]
[/color][color=#008080]31[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/None.gif[/img] [/color][color=#0000ff]<[/color][color=#800000]TextBlock [/color][color=#ff0000]Grid.Column[/color][color=#0000ff]="0"[/color][color=#ff0000] Grid.Row[/color][color=#0000ff]="1"[/color][color=#0000ff]>[/color][color=#000000]Green:[/color][color=#0000ff]</[/color][color=#800000]TextBlock[/color][color=#0000ff]>[/color]
[color=#008080]32[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/None.gif[/img] [/color][color=#0000ff]<[/color][color=#800000]Slider [/color][color=#ff0000]Grid.Column[/color][color=#0000ff]="1"[/color][color=#ff0000] Grid.Row[/color][color=#0000ff]="1"[/color]
[color=#008080]33[/color][color=#ff0000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/None.gif[/img] Minimum[/color][color=#0000ff]="0"[/color][color=#ff0000] Maximum[/color][color=#0000ff]="255"[/color][color=#ff0000] [color=#ff0000]Value[/color][color=#0000ff]="{Binding Path=Green}"[/color][/color][color=#0000ff]/>[/color]
[color=#008080]34[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/None.gif[/img]
[/color][color=#008080]35[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/None.gif[/img] [/color][color=#0000ff]<[/color][color=#800000]TextBlock [/color][color=#ff0000]Grid.Column[/color][color=#0000ff]="0"[/color][color=#ff0000] Grid.Row[/color][color=#0000ff]="2"[/color][color=#0000ff]>[/color][color=#000000]Blue:[/color][color=#0000ff]</[/color][color=#800000]TextBlock[/color][color=#0000ff]>[/color]
[color=#008080]36[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/None.gif[/img] [/color][color=#0000ff]<[/color][color=#800000]Slider [/color][color=#ff0000]Grid.Column[/color][color=#0000ff]="1"[/color][color=#ff0000] Grid.Row[/color][color=#0000ff]="2"[/color]
[color=#008080]37[/color][color=#ff0000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/None.gif[/img] Minimum[/color][color=#0000ff]="0"[/color][color=#ff0000] Maximum[/color][color=#0000ff]="255"[/color][color=#ff0000] [color=#ff0000]Value[/color][color=#0000ff]="{Binding Path=Blue}[/color][/color][color=#0000ff]"[/color][color=#0000ff]/>[/color]
[color=#008080]38[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/None.gif[/img]
[/color][color=#008080]39[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/None.gif[/img] [/color][color=#0000ff]<[/color][color=#800000]Border [/color][color=#ff0000]Grid.Column[/color][color=#0000ff]="2"[/color][color=#ff0000] Grid.Row[/color][color=#0000ff]="0"[/color][color=#ff0000] Grid.RowSpan[/color][color=#0000ff]="3"[/color][color=#ff0000] Margin[/color][color=#0000ff]="5, 5, 5, 5"[/color][color=#0000ff]>[/color]
[color=#008080]40[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/None.gif[/img] [/color][color=#0000ff]<[/color][color=#800000]Border [/color][color=#ff0000]BorderThickness[/color][color=#0000ff]="1"[/color][color=#ff0000] CornerRadius[/color][color=#0000ff]="5"[/color][color=#ff0000] BorderBrush[/color][color=#0000ff]="Gray"[/color][color=#ff0000] [color=#ff0000]Background[/color][color=#0000ff]="{Binding Path=Background}"[/color][/color][color=#0000ff]/>[/color]
[color=#008080]41[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/None.gif[/img] [/color][color=#0000ff]</[/color][color=#800000]Border[/color][color=#0000ff]>[/color]
[color=#008080]42[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/None.gif[/img] [/color][color=#0000ff]</[/color][color=#800000]Grid[/color][color=#0000ff]>[/color]
[color=#008080]43[/color][color=#000000][img=11,16]http://www.cnblogs.com/Images/OutliningIndicators/None.gif[/img][/color][color=#0000ff]</[/color][color=#800000]Window[/color][color=#0000ff]>[/color] [/size]
与前一个XAML不同的地方主要在于黄色标注的部分。
在行10-12中，我们将一个ColorPickerData数据包作为一个资源嵌入到这个XAML中来。并且将Grid的当前数据内容映射到这个数据包上（行13-15声明）。
然后将后面的三个Slider的Value属性分别绑在数据包的几个不同的属性上。将Border的Background也绑定到数据包的Background属性上。
Ok，看起来展示层已经描述的很清楚了。WPF项目组的一个PM（产品经理）看着这个设计露出了非常满足的笑容。清晰，明了，解决了大多数的用户需求。如果你是WPF项目组中的一个开发人员，现在你一定会跳得很高。
“不可能，我怎么知道数据层什么时候变化了？”
“不可能，你所描述的结构，我必须使用反射来读取数据，这样的性能将是无法接受的。”
“不可能…………”你想了想，说：“对不起，麻烦问一下，‘{Binding Path=Blue}’似乎没有见过，代表什么呢？” [b]-_-![/b]