DependencyObject Binding
在Silverlight之前的版本中,其支持的元素绑定只是允许绑定继承自FrameworkElement类下元素,但是比如一些形变比如Transformations就不能绑定了。现在数据绑定也可以绑定继承自DependencyObject下的任何元素。
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代码语言:javascript复制 <Grid x:Name="LayoutRoot"
Background="White">
<StackPanel Width="400" Margin="0,22,0,0">
<StackPanel.RenderTransform>
<CompositeTransform
ScaleX="{Binding Value,ElementName=stretcher}"
ScaleY="{Binding Value,ElementName=stretcher}" />
</StackPanel.RenderTransform>
<Button Content="Button"/>
<Button Content="Button"/>
<Button Content="Button"/>
<Button Content="Button"/>
<Button Content="Button"/>
</StackPanel>
<Slider Minimum=".5"
Maximum="4"
x:Name="stretcher"
Value="1" VerticalAlignment="Top" />
</Grid>
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String Formatting 新版的Silverlight4中新增加了格式化字符串的能力。在这之前如果要做一个数据格式化不得不使用一个Converter来格式化字符串。现在可以使用扩展标记StringFormat来做一些比如日期、货币等的格式化。
在VS2010中也提供了可视化的支持。
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代码语言:javascript复制 <Grid x:Name="LayoutRoot" Background="White">
<TextBox Text="{Binding ReleaseDate, StringFormat='yyyy年MM月dd日',
Mode=TwoWay}"
Margin="0,30,0,0"
Height="26"
VerticalAlignment="Top" d:LayoutOverrides="Height" />
<TextBlock Text="{Binding Price, StringFormat='c'}"
Margin="0,0,0,0"
Height="26" VerticalAlignment="Top" />
</Grid>
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Null and Fallback Values 在某些特殊的情况下,数据有可能加载失败。数据绑定中有新增加了两个宽展标记TargetNullValue、FallbackValue,TargetNullValue这个标记表示了当绑定值是null的时候显示的值。FallbackValue则是在数据未绑定时显示的值。 =================================
代码语言:javascript复制 <Grid x:Name="LayoutRoot" Background="White">
<TextBlock Text="{Binding Developer,
TargetNullValue='(暂无)'}"
Height="26" Margin="0,100,0,0"
VerticalAlignment="Top" d:LayoutOverrides="Height" />
<TextBlock Text="{Binding Publisher,
FallbackValue='(暂无)'}" Height="26"
VerticalAlignment="Top" Margin="0,33,0,0" />
</Grid>
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CollectionViewSource Changes 对于在GataGrid中做分组管理,现在的CollectionViewSource支持数据到GroupDescriptions的绑定,这样可以更加轻松的在XAML做分组。
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代码语言:javascript复制 <UserControl.Resources>
<CollectionViewSource x:Name="dataSource"
Source="{Binding}">
<CollectionViewSource.GroupDescriptions>
<PropertyGroupDescription PropertyName="Gender" />
<PropertyGroupDescription PropertyName="AgeGroup" />
</CollectionViewSource.GroupDescriptions>
<CollectionViewSource.SortDescriptions>
<compMod:SortDescription PropertyName="AgeGroup" Direction="Ascending"/>
</CollectionViewSource.SortDescriptions>
</CollectionViewSource>
</UserControl.Resources>
<Grid x:Name="LayoutRoot" Background="White">
<sdk:DataGrid ItemsSource="{Binding Source={StaticResource dataSource}}" />
</Grid>
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代码语言:javascript复制 public List<Person> GetPeople()
{
List<Person> peeps = new List<Person>();
peeps.Add(new Person() { FirstName = "Wang", LastName = "Zhe", Gender = "M", AgeGroup = "Adult" });
peeps.Add(new Person() { FirstName = "nasa", LastName = "wang", Gender = "M", AgeGroup = "Adult" });
peeps.Add(new Person() { FirstName = "summer", LastName = "liang", Gender = "F", AgeGroup = "Kid" });
peeps.Add(new Person() { FirstName = "liang", LastName = "jing", Gender = "F", AgeGroup = "Kid" });
return peeps;
}
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Error Propogation Silverlight的数据验证机制,在这里得到了很多的扩充,提供了IDataErrorInfo、INotifyDataErrorInfo从而能得到更多的信息。