Silverlight 4常用StringFormat格式总结

在Silverlight项目中，经常会根据需求的不同，提供不同的字符格式到客户端。这篇文章总结了目前Silverlight 4常用StringFormat绑定字符格式，方便大家在以后的开发中调用参考。

早期的格式转换方法

在Silverlight 4之前的版本，通常修改字符格式是通过实现IValueConverter接口，在IValueConverter接口中包含有两个方法：

1. Convert， 在绑定源数据传送到客户端显示前，转换修改数据；

2. ConvertBack，在目标数据传送到绑定源数据前，转换修改数据，该方法仅被用于“TwoWay”绑定模式；

例如，根据布尔型判断实现控件是否显示在客户端，下面是一个简单的转换代码，通过实现IValueConverter，判断控件Visibility属性值。

 

 1 public class VisibilityConverter : IValueConverter
 2 
 3 {
 4 
 5 public object Convert(object value,Type targetType,object parameter,CultureInfo culture)
 6 
 7 {
 8 
 9 bool visibility = (bool)value;
10 
11 return visibility ? Visibility.Visible : Visibility.Collapsed;
12 
13 }
14 
15 public object ConvertBack(object value,Type targetType,object parameter,CultureInfo culture)
16 
17 {
18 
19 Visibility visibility = (Visibility)value;
20 
21 return (visibility == Visibility.Visible);
22 
23 }
24 
25 }

 

 

Silverlight 4的StringFormat属性

在Silverlight 4中，数据绑定SDK提供一个“StringFormat”的属性，该属性允许开发人员自由定义输出字符格式，例如，DataPicker控件，该控件提供SelectedDateFormat属性，控制其输出格式“短格式”或“长格式”。

SelectedDateFormat="Short", “默认”

SelectedDateFormat="Long"

而如果需要输出“April 01, 2011”格式，则无法使用SelectedDateFormat控制其格式，这时可以使用StringFormat属性完成需求。

<toolkit:DatePicker SelectedDate="{Binding DemoDate,Mode=TwoWay, StringFormat='MMM d, yyyy'}" />

再例如，早期实现一段文字绑定信息需要按照以下格式操作：

<TextBlock Text=”当前登录用户: ”/>

<TextBlock Text=“{Binding Name}”/>

输出: 当前登录用户Jv9

在Silverlight 4中使用StringFormat属性，可以简单的实现如下:

<TextBlock Text=“{Binding Name, StringFormat=’当前登录用户: /{0/}’}”>

这样实现简单而又方便。

对于StringFormat属性的使用方法还有很多，下面使用实例演示常用的属性：

 

  1 <Grid x:Name="LayoutRoot">
  2 <ScrollViewer x:Name="PageScrollViewer" Style="{StaticResource PageScrollViewerStyle}">
  3 <StackPanel Orientation="Horizontal">
  4 <StackPanel x:Name="ContentStackPanel">
  5 <TextBlock FontSize="16" TextWrapping="Wrap" Text="StringFormat和字符串格式" Margin="8"/>
  6 <Border BorderBrush="LightGray" BorderThickness="1" Width="300" Margin="5" HorizontalAlignment="Left">
  7 <StackPanel Orientation="Vertical" Margin="5" >
  8 <TextBox x:Name="txtSource" Width="125" HorizontalAlignment="Left"/>
  9 <TextBlock TextWrapping="Wrap" Text="StringFormat='正在输入 &quot;/{0/}&quot;." FontWeight="Bold" Margin="0,4,0,2"/>
 10 <TextBlock Text="{Binding Text, ElementName=txtSource, StringFormat='正在输入 &quot;/{0/}&quot;.'}" TextWrapping="Wrap" Margin="0,0,0,4"/>
 11 <TextBlock TextWrapping="Wrap" Text="StringFormat=/{0/,20/}" FontWeight="Bold" Margin="0,4,0,2"/>
 12 <TextBlock Text="{Binding Text, ElementName=txtSource, StringFormat=/{0/,20/}}" TextWrapping="Wrap" Margin="0,0,0,4" />
 13 <TextBlock TextWrapping="Wrap" Text="StringFormat=/{0/,-20/}" FontWeight="Bold" Margin="0,4,0,2"/>
 14 <TextBlock Text="{Binding Text, ElementName=txtSource, StringFormat=/{0/,-20/}}" TextWrapping="Wrap" Margin="0,0,0,4"/>
 15 </StackPanel>
 16 </Border>
 17 
 18 <StackPanel x:Name="DatePanel">
 19 <TextBlock Text="StringFormat和日期格式" Margin="8" FontSize="16" />
 20 <Border BorderBrush="LightGray" BorderThickness="1" Width="300" Margin="5" HorizontalAlignment="Left">
 21 <StackPanel DataContext="{StaticResource SampleDate}">
 22 <TextBlock TextWrapping="Wrap" Text="StringFormat=f" FontWeight="Bold" Margin="0,4,0,2"/>
 23 <TextBlock TextWrapping="Wrap" Text="{Binding CurrentDateTime, StringFormat=f}" Margin="8,0" />
 24 <TextBlock TextWrapping="Wrap" Text="StringFormat=F" FontWeight="Bold" Margin="0,4,0,2"/>
 25 <TextBlock TextWrapping="Wrap" Text="{Binding CurrentDateTime, StringFormat=F}" Margin="8,0" />
 26 <TextBlock TextWrapping="Wrap" Text="StringFormat=g" FontWeight="Bold" Margin="0,4,0,2"/>
 27 <TextBlock TextWrapping="Wrap" Text="{Binding CurrentDateTime, StringFormat=g}" Margin="8,0" />
 28 <TextBlock TextWrapping="Wrap" Text="StringFormat=G" FontWeight="Bold" Margin="0,4,0,2"/>
 29 <TextBlock TextWrapping="Wrap" Text="{Binding CurrentDateTime, StringFormat=G}" Margin="8,0" />
 30 <TextBlock TextWrapping="Wrap" Text="StringFormat=m" FontWeight="Bold" Margin="0,4,0,2"/>
 31 <TextBlock TextWrapping="Wrap" Text="{Binding CurrentDateTime, StringFormat=m}" Margin="8,0" />
 32 <TextBlock TextWrapping="Wrap" Text="StringFormat=y" FontWeight="Bold" Margin="0,4,0,2"/>
 33 <TextBlock TextWrapping="Wrap" Text="{Binding CurrentDateTime, StringFormat=y}" Margin="8,0" />
 34 <TextBlock TextWrapping="Wrap" Text="StringFormat=t" FontWeight="Bold" Margin="0,4,0,2"/>
 35 <TextBlock TextWrapping="Wrap" Text="{Binding CurrentDateTime, StringFormat=t}" Margin="8,0" />
 36 <TextBlock TextWrapping="Wrap" Text="StringFormat=T" FontWeight="Bold" Margin="0,4,0,2"/>
 37 <TextBlock TextWrapping="Wrap" Text="{Binding CurrentDateTime, StringFormat=T}" Margin="8,0" />
 38 <TextBlock TextWrapping="Wrap" Text="StringFormat=u" FontWeight="Bold" Margin="0,4,0,2"/>
 39 <TextBlock TextWrapping="Wrap" Text="{Binding CurrentDateTime, StringFormat=u}" Margin="8,0" />
 40 <TextBlock TextWrapping="Wrap" Text="StringFormat=o" FontWeight="Bold" Margin="0,4,0,2"/>
 41 <TextBlock TextWrapping="Wrap" Text="{Binding CurrentDateTime, StringFormat=o}" Margin="8,0" />
 42 <TextBlock TextWrapping="Wrap" Text="StringFormat=MM/dd/yy" FontWeight="Bold" Margin="0,4,0,2"/>
 43 <TextBlock TextWrapping="Wrap" Text="{Binding CurrentDateTime, StringFormat=MM/dd/yy}" Margin="8,0"/>
 44 <TextBlock TextWrapping="Wrap" Text="StringFormat=MMMM dd/, yyyy g" FontWeight="Bold" Margin="0,4,0,2"/>
 45 <TextBlock TextWrapping="Wrap" Text="{Binding CurrentDateTime, StringFormat=MMMM dd/, yyyy g}" Margin="8,0" />
 46 <TextBlock TextWrapping="Wrap" Text="StringFormat=hh:mm:ss.fff tt" FontWeight="Bold" Margin="0,4,0,2"/>
 47 <TextBlock TextWrapping="Wrap" Text="{Binding CurrentDateTime, StringFormat=hh:mm:ss.fff tt}" Margin="8,0" />
 48 <TextBlock TextWrapping="Wrap" Text="StringFormat=/{0:r/}" FontWeight="Bold" Margin="0,4,0,2"/>
 49 <TextBlock TextWrapping="Wrap" Text="{Binding CurrentDateTime, StringFormat=/{0:r/}}" Margin="8,0" />
 50 <TextBlock TextWrapping="Wrap" Text="StringFormat='MMM d, yyyy'" FontWeight="Bold" Margin="0,4,0,2"/>
 51 <TextBlock TextWrapping="Wrap" Text="{Binding CurrentDateTime, StringFormat='MMM d, yyyy'}" Margin="8,0" />
 52 </StackPanel>
 53 </Border> 
 54 </StackPanel>
 55 </StackPanel>
 56 <StackPanel Orientation="Vertical" >
 57 <TextBlock Text="StringFormat和数字演示" Margin="8" FontSize="16"/>
 58 <Border BorderBrush="LightGray" BorderThickness="1" Width="300" Margin="5" HorizontalAlignment="Left">
 59 <StackPanel Orientation="Vertical" Margin="5">
 60 <Grid >
 61 <Grid.RowDefinitions>
 62 <RowDefinition Height="Auto"/>
 63 <RowDefinition Height="Auto"/>
 64 </Grid.RowDefinitions>
 65 <Grid.ColumnDefinitions>
 66 <ColumnDefinition Width="Auto" MinWidth="18"/>
 67 <ColumnDefinition/>
 68 <ColumnDefinition Width="Auto" MinWidth="28"/>
 69 </Grid.ColumnDefinitions>
 70 <TextBlock Text="1" HorizontalAlignment="Left" d:LayoutOverrides="Height" />
 71 <TextBlock Text="100,000" d:LayoutOverrides="Width, Height" Grid.Column="2" Margin="0" />
 72 <Slider x:Name="BigNumSlider" Margin="0" d:LayoutOverrides="Height" Grid.ColumnSpan="3" Grid.Row="1" Maximum="100000" Minimum="1" Value="50000"/>
 73 </Grid>
 74 <TextBlock TextWrapping="Wrap" Text="StringFormat=c" FontWeight="Bold" Margin="0,4,0,2"/>
 75 <TextBox TextWrapping="Wrap" Text="{Binding Value, ElementName=BigNumSlider, Mode=TwoWay, StringFormat=c}" Margin="8,0"/>
 76 <TextBlock TextWrapping="Wrap" Text="StringFormat=目前拥有现金 /{0:C0/}" FontWeight="Bold" Margin="0,4,0,2"/>
 77 <TextBox TextWrapping="Wrap" Text="{Binding Value, ElementName=BigNumSlider, Mode=TwoWay, StringFormat=目前拥有现金 /{0:C0/}}" Margin="8,0"/>
 78 <TextBlock TextWrapping="Wrap" Text="StringFormat=e" FontWeight="Bold" Margin="0,4,0,2"/>
 79 <TextBox TextWrapping="Wrap" Text="{Binding Value, ElementName=BigNumSlider, Mode=TwoWay, StringFormat=e}" Margin="8,0"/>
 80 <TextBlock TextWrapping="Wrap" Text="StringFormat=/{0:E4/}" FontWeight="Bold" Margin="0,4,0,2"/>
 81 <TextBox TextWrapping="Wrap" Text="{Binding Value, ElementName=BigNumSlider, Mode=TwoWay, StringFormat=/{0:E4/}}" Margin="8,0"/>
 82 <TextBlock TextWrapping="Wrap" Text="StringFormat=n" FontWeight="Bold" Margin="0,4,0,2"/>
 83 <TextBox TextWrapping="Wrap" Text="{Binding Value, ElementName=BigNumSlider, Mode=TwoWay, StringFormat=n}" Margin="8,0"/>
 84 <TextBlock TextWrapping="Wrap" Text="StringFormat=/{0:N0/}" FontWeight="Bold" Margin="0,4,0,2"/>
 85 <TextBox TextWrapping="Wrap" Text="{Binding Value, ElementName=BigNumSlider, Mode=TwoWay, StringFormat=/{0:N0/}}" Margin="8,0"/>
 86 <TextBlock TextWrapping="Wrap" Text="StringFormat='###,###.##'" FontWeight="Bold" Margin="0,4,0,2"/>
 87 <TextBox TextWrapping="Wrap" Text="{Binding Value, ElementName=BigNumSlider, Mode=TwoWay, StringFormat='###,###.##'}" Margin="8,0" />
 88 </StackPanel>
 89 </Border>
 90 <Border BorderBrush="LightGray" BorderThickness="1" Width="300" Margin="5" HorizontalAlignment="Left">
 91 <StackPanel Orientation="Vertical" Margin="5">
 92 <Grid >
 93 <Grid.RowDefinitions>
 94 <RowDefinition Height="Auto"/>
 95 <RowDefinition Height="Auto"/>
 96 </Grid.RowDefinitions>
 97 <Grid.ColumnDefinitions>
 98 <ColumnDefinition Width="Auto" MinWidth="18"/>
 99 <ColumnDefinition/>
100 <ColumnDefinition Width="Auto" MinWidth="28"/>
101 </Grid.ColumnDefinitions>
102 <TextBlock Text="-1" HorizontalAlignment="Left" d:LayoutOverrides="Height" />
103 <TextBlock Text="1" d:LayoutOverrides="Width, Height" Grid.Column="2" Margin="0" />
104 <Slider x:Name="BigNumSlider1" Margin="0" d:LayoutOverrides="Height" Grid.ColumnSpan="3" Grid.Row="1" Maximum="1" Minimum="-1" Value="0.2" LargeChange="0.1" SmallChange="0.01"/>
105 </Grid>
106 <TextBlock TextWrapping="Wrap" Text="StringFormat=n" FontWeight="Bold" Margin="0,4,0,2"/>
107 <TextBox TextWrapping="Wrap" Text="{Binding Value, ElementName=BigNumSlider1, Mode=TwoWay, StringFormat=n}" Margin="8,0"/>
108 <TextBlock TextWrapping="Wrap" Text="StringFormat=/{0:N4/}" FontWeight="Bold" Margin="0,4,0,2"/>
109 <TextBox TextWrapping="Wrap" Text="{Binding Value, ElementName=BigNumSlider1, Mode=TwoWay, StringFormat=/{0:N4/}}" Margin="8,0"/>
110 <TextBlock TextWrapping="Wrap" Text="StringFormat=p" FontWeight="Bold" Margin="0,4,0,2"/>
111 <TextBox TextWrapping="Wrap" Text="{Binding Value, ElementName=BigNumSlider1, Mode=TwoWay, StringFormat=p}" Margin="8,0"/>
112 <TextBlock TextWrapping="Wrap" Text="StringFormat=/{0:P0/}" FontWeight="Bold" Margin="0,4,0,2"/>
113 <TextBox TextWrapping="Wrap" Text="{Binding Value, ElementName=BigNumSlider1, Mode=TwoWay, StringFormat=/{0:P0/}}" Margin="8,0"/>
114 <TextBlock TextWrapping="Wrap" Text="StringFormat=/{0:E5/}" FontWeight="Bold" Margin="0,4,0,2"/>
115 <TextBox TextWrapping="Wrap" Text="{Binding Value, ElementName=BigNumSlider1, Mode=TwoWay, StringFormat=/{0:E5/}}" Margin="8,0"/>
116 <TextBlock TextWrapping="Wrap" Text="StringFormat=/{0:C3/}" FontWeight="Bold" Margin="0,4,0,2"/>
117 <TextBox TextWrapping="Wrap" Text="{Binding Value, ElementName=BigNumSlider1, Mode=TwoWay, StringFormat=/{0:C3/}}" Margin="8,0"/>
118 </StackPanel>
119 </Border>
120 </StackPanel>
121 
122 </StackPanel>
123 </ScrollViewer>
124 </Grid>

 

 

源代码下载

在线演示

 

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