我有一个带有以下XAML的测试WPF窗口:
<Window x:Class="WpfApplication2.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:wpfApplication2="clr-namespace:WpfApplication2"
xmlns:test="clr-namespace:WpfApplication2.Properties"
DataContext="{Binding Path=TestClass}"
Title="MainWindow" Height="350" Width="525" >
<Window.Resources>
<wpfApplication2:TestTypeConverter x:Key="TestConverter"/>
</Window.Resources>
<Grid>
<Grid Visibility="{Binding TestProperty, Converter={StaticResource TestConverter}, ConverterParameter='nottest'}">
<Label Content="Test Label"></Label>
</Grid>
</Grid>
</Window>
我有一个测试类型转换器类,如下所示:
using System;
using System.Globalization;
using System.Windows.Data;
namespace WpfApplication2
{
class TestTypeConverter : IValueConverter
{
public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
{
var valueToTest = (string) value;
var parameterToCheck = (string) parameter;
return valueToTest == parameterToCheck ? System.Windows.Visibility.Visible : System.Windows.Visibility.Collapsed;
}
public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
{
return value;
}
}
}
TestClass如下:
using System.ComponentModel;
using System.Runtime.CompilerServices;
using WpfApplication2.Annotations;
namespace WpfApplication2
{
public class TestClass : INotifyPropertyChanged
{
public TestClass()
{
TestProperty = "test";
}
private string _testProperty;
public string TestProperty
{
get { return _testProperty; }
set
{
if (_testProperty == value)
{
return;
}
_testProperty = value;
OnPropertyChanged();
}
}
public event PropertyChangedEventHandler PropertyChanged;
[NotifyPropertyChangedInvocator]
protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null)
{
var handler = PropertyChanged;
if (handler != null) handler(this, new PropertyChangedEventArgs(propertyName));
}
}
}
可见性属性不受类型转换器的影响,并且甚至没有调用Convert方法本身(我已经放置了一个未被命中的断点)。
我做错了什么?
由于
答案 0 :(得分:2)
您的绑定似乎有误:
Visibility="{Binding 'test', Converter={StaticResource TestConverter}, ConverterParameter='nottest'}"
将其更改为:
Visibility="{Binding test, Converter={StaticResource TestConverter}, ConverterParameter='nottest'}"
如果属性测试不存在,则不会调用转换器
答案 1 :(得分:1)
为转换器参数创建资源(如下面的代码段所示),并使用资源作为转换器参数而不是文字
<Window x:Class="WpfApplication2.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:wpfApplication2="clr-namespace:WpfApplication2"
xmlns:test="clr-namespace:WpfApplication2.Properties"
xmlns:sys="clr-namespace:System;assembly=mscorlib"
DataContext="{Binding Path=TestClass}"
Title="MainWindow" Height="350" Width="525" >
<Window.Resources>
<wpfApplication2:TestTypeConverter x:Key="TestConverter"/>
<sys:String x:Key="converterParam">nottest</sys:String>
</Window.Resources>
<Grid>
<Grid Visibility="{Binding TestProperty, Converter={StaticResource TestConverter}, ConverterParameter={StaticResource converterParam}">
<Label Content="Test Label"></Label>
</Grid>
</Grid>
</Window>
答案 2 :(得分:0)
如果你没有datacontext就可以完全省略属性的名称并且它会起作用,以下内容对我来说很糟糕。
Visibility =“{Binding Converter = {StaticResource myTestConverter}}”
//看看关键字如何跟随关键字Binding关键字,我没有在Binding关键字后指定属性名称。