WPF 值转换

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

<Button Margin=“3” Content=“Start” x:Name=“btnStart”

IsEnabled=“{Binding LicenseExpired, Converter={StaticResource bool2Inverter}}”/>

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”>

<TextBlock Text=“{Binding ElementName=bd,Path=BorderThickness,UpdateSourceTrigger=PropertyChanged}”

FontSize=“{Binding BoolProperty ,Converter={StaticResource bool2Int},Mode=OneWayToSource}”/>

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”/>

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”/>

输入字符串为空时，Button 不可用，字符串输入不为空时，Enable