IValueConvert的例子
在MVVM中经常遇到控制界面显示的问题
下面来一段代码用true和false来控制界面的显示
先写一个类实现接口IValueConvert
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1 public class BoolToVisibilityConvert:IValueConverter 2 { 3 public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture) 4 { 5 bool trueOrFalse = (bool)value; 6 string str = trueOrFalse ? "Visible" : "Collapsed"; 7 return str; 8 } 9 10 public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture) 11 { 12 string visibility = (string)value; 13 switch (visibility) 14 { 15 case "Visible": 16 return true; 17 case "Hidden": 18 return false; 19 case "Collapsed": 20 return false; 21 default: 22 return false; 23 } 24 } 25 }
然后再xaml界面定义一下
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1 <Window x:Class="Test1BoolenToVisiableConvert.MainWindow" 2 xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 3 xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 4 xmlns:Converter="clr-namespace:Test1BoolenToVisiableConvert" 5 Title="MainWindow" Height="350" Width="525"> 6 <Window.Resources> 7 <Converter:BoolToVisibilityConvert x:Key="booltovisibleConvert"/> 8 </Window.Resources> 9 <Grid> 10 <TextBlock Text="BoolToVisibleConvert" 11 HorizontalAlignment="Center" VerticalAlignment="Center" 12 Visibility="{Binding ShowText,Converter={StaticResource booltovisibleConvert}}"/> 13 </Grid> 14 </Window>
那么在对应的ViewModel中就可以用了
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1 public class MainWindowViewModel 2 { 3 public MainWindowViewModel() 4 { ShowText = true; } 5 6 public bool ShowText { get; set; } 7 }
简单的一个demo写完了