Value Converter
首先需要添加引用
using System.Windows.Data;
1.实现Bool值取反转换
internal class bool2InverterConverter : IValueConverter
{
public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
{
return !(bool)value;
}
public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
{
throw new NotImplementedException();
}
}
UI设计绑定转换类
<DockPanel Grid.Row="0" Margin="3">
<TextBlock DockPanel.Dock="Left" VerticalAlignment="Center">License expired</TextBlock>
<TextBlock DockPanel.Dock="Left" VerticalAlignment="Center" Foreground="Green" FontWeight="Black" Text="{Binding LicenseExpired}" Padding="3"/>
<Button Margin="3" Content="Start" x:Name="btnStart"
IsEnabled="{Binding LicenseExpired, Converter={StaticResource bool2Inverter}}"/>
</DockPanel>
UI 后台代码：
public partial class MainWindow : Window
{
public bool LicenseExpired { get; set; } = true;
public MainWindow()
{
InitializeComponent();
this.DataContext = this;
}
}
设计一个布尔属性，初始化绑定到自身后，使用窗口类的布尔属性，初始值true，但是经过转换Converter={StaticResource bool2Inverter} 后，取反
值 True取反，所以Button是Disable
2. 实现Bool 转换为整型值
internal class bool2IntConverter : IValueConverter
{
public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
{
return (bool)value ? 5:2;
}
public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
{
return System.Convert.ToInt32(value) < 5 ? false : true;
}
}
如果是true 返回整数5，否则返回2
UI设计绑定
添加Windows 资源：
<local:bool2IntConverter x:Key="bool2Int"/>
绑定Window资源转换类
<Border Grid.Row="1" Margin="3" x:Name="bd"
BorderThickness="{Binding HasThickBorder,Converter={StaticResource bool2Int }}" BorderBrush="Black">
<StackPanel HorizontalAlignment="Center" VerticalAlignment="Center">
<TextBlock Text="BorderThickness:"/>
<TextBlock Text="{Binding ElementName=bd,Path=BorderThickness,UpdateSourceTrigger=PropertyChanged}"
FontSize="{Binding BoolProperty ,Converter={StaticResource bool2Int},Mode=OneWayToSource}"/>
</StackPanel>
</Border>
HasThickBorder 窗口类的属性字段
public bool HasThickBorder { get; set; } = true;
public bool BoolProperty { get; set; }=true;
3. 整型转换到字符串
internal class Int2StringConverter : IValueConverter
{
public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
{
if (parameter != null)
return System.Convert.ToInt32(parameter) >= 60?"Passed":"Failed";
else
return System.Convert.ToInt32(value)>=60 ?"Passed":"Failed";
}
public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
{
return System.Convert.ToInt32(value) < 15 ? false : true;
}
}
UI设计
<local:Int2StringConverter x:Key="Int2Str"/>
<TextBox Text="{Binding Grade,Converter={StaticResource Int2Str},ConverterParameter=45}"></TextBox>
UI后台代码设计字段：
public int Grade { get; set; } = 50;
4. 字符串是否为空转换为可见/不可见属性
转换类型
internal class StringEmpty2BoolConverter : IValueConverter
{
public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
{
return value.ToString().Equals(string.Empty)?false:true;
}
public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
{
return System.Convert.ToInt32(value) < 15 ? false : true;
}
}
UI设计：
<local:StringEmpty2BoolConverter x:Key="str2Bool"/>
<TextBox Grid.Column="1" Name="tb_input" Padding="5 0" Margin="5"/>
<Button Grid.Column="2" Content="Submit" IsEnabled="{Binding ElementName=tb_input, Path=Text, Converter={StaticResource str2Bool}}" />
输入字符串为空时，Button 不可用，字符串输入不为空时，Enable
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