我正在尝试将 View 与 ResourceDictionary 中的 ViewModel 绑定,但它不起作用。
该应用程序是一个非常简单的窗口,带有 2 个文本框。当我向 textbox1 键入文本时,textbox2 必须自动获得相同的文本。当然,视图中的文本框必须绑定到视图模型中的属性。
我是 WPF 新手,我开始绑定 View 和 ViewModel 的方式是在 View 的代码隐藏中:
DataContext = new MyViewModel();
现在我正在尝试实现更清洁的分离。我的代码是
应用程序.xaml:
<Application x:Class="NavigationCleanBinding.App"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
StartupUri="/Views/MainWindowView.xaml">
<Application.Resources>
<ResourceDictionary Source="MainResourceDictionary.xaml" />
</Application.Resources>
</Application>
MainResourceDictionary.xaml:
<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xamlpresentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:Views="clr-namespace:NavigationCleanBinding.Views"
xmlns:ViewModels="clr-namespace:NavigationCleanBinding.ViewModels">
<DataTemplate DataType="{x:Type ViewModels:MainWindowViewModel}">
<Views:MainWindowView />
</DataTemplate>
</ResourceDictionary>
MainWindowView.xaml:
<Window x:Class="NavigationCleanBinding.Views.MainWindowView"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="MainWindow" Height="350" Width="525">
<Grid>
<TextBox Height="23" HorizontalAlignment="Left" Margin="61,14,0,0"
Name="textBox1" VerticalAlignment="Top" Width="120"
Text="{Binding TestData, Mode=TwoWay,
UpdateSourceTrigger=PropertyChanged}"/>
<Label Content="Test:" Height="28" HorizontalAlignment="Left" Margin="12,12,0,0"
Name="label1" VerticalAlignment="Top" Width="43" />
<Label Content="Result:" Height="28" HorizontalAlignment="Left" Margin="10,46,0,0"
Name="label2" VerticalAlignment="Top" />
<TextBox Height="23" HorizontalAlignment="Left" Margin="61,48,0,0"
Name="textBox2" VerticalAlignment="Top" Width="120"
Text="{Binding TestData, Mode=TwoWay,UpdateSourceTrigger=PropertyChanged}"/>
</Grid>
</Window>
主窗口视图模型:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace NavigationCleanBinding.ViewModels
{
class MainWindowViewModel
{
private String _testData;
public String TestData
{
get { return _testData; }
set { _testData = value; }
}
private MainWindowViewModel()
{
_testData = null;
}
}
}
更新:
我将属性 TestData 更改为:
public String TestData
{
get { return _testData; }
set
{
_testData = value;
OnPropertyChanged("TestData");
}
}
并像这样实现了 INotifyPropertyChanged:
public event PropertyChangedEventHandler PropertyChanged;
private void OnPropertyChanged(String propertyName)
{
PropertyChangedEventHandler handler = PropertyChanged;
if (handler != null)
{
handler(this, new PropertyChangedEventArgs(propertyName));
}
}