C# 当依赖的变量或字段发生更改时，更新依赖属性
我需要做的是什么 我需要做一个表达式，依赖属性应该依赖于这个表达式 假设如下：C# 当依赖的变量或字段发生更改时，更新依赖属性,c#,.net,wpf,dependency-properties,C#,.net,Wpf,Dependency Properties,我需要做的是什么 我需要做一个表达式，依赖属性应该依赖于这个表达式 假设如下： Count = dependOne + dependTwo; 这里，Count是依赖性属性和dependOne和dependTwo是依赖性属性Count应该依赖的两个变量 现在，每当我更改变量dependOne或dependtow2时，依赖项属性都必须自动更新 可能吗？如果是，那怎么办 请参见下面的代码 XAML: <Window x:Class="DependecnyProperty.MainWindow"
Count = dependOne + dependTwo;
CountdependOnedependTwoCountdependOnedependtow2<Window x:Class="DependecnyProperty.MainWindow"
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 Background="LightGray" Text="{Binding Path=Count}" Height="23" HorizontalAlignment="Left" Margin="164,102,0,0" Name="textBox1" VerticalAlignment="Top" Width="120" />
<Button Content="Button" Height="23" HorizontalAlignment="Left" Margin="164,148,0,0" Name="button1" VerticalAlignment="Top" Width="120" Click="button1_Click" />
</Grid>
</Window>
namespace DependecnyProperty
{
/// <summary>
/// Interaction logic for MainWindow.xaml
/// </summary>
public partial class MainWindow : Window
{
public MainWindow()
{
InitializeComponent();
this.DataContext = this;
Count = dependOne + dependTwo;
}
int dependOne = 0;
int dependTwo = 0;
public int Count
{
get { return (int)GetValue(CountProperty); }
set { SetValue(CountProperty, value); }
}
// Using a DependencyProperty as the backing store for Count. This enables animation, styling, binding, etc...
public static readonly DependencyProperty CountProperty =
DependencyProperty.Register("Count", typeof(int), typeof(MainWindow), new UIPropertyMetadata(12));
private void button1_Click(object sender, RoutedEventArgs e)
{
dependOne = dependOne + 2;
dependTwo = dependTwo + 1;
//I need to find way ...now here i have changed value of two variable.
//now it is possible to change Dependency Property
//Without here setting the value of dependency property
}
}
}
namespace DependecnyProperty
{
/// <summary>
/// Interaction logic for MainWindow.xaml
/// </summary>
public partial class MainWindow : Window
{
ViewModel vm;
public MainWindow()
{
InitializeComponent();
this.DataContext = this;
vm = new ViewModel();
//this.DataContext = vm;
Count = vm.DependOne + vm.DependTwo;
}
public int Count
{
get { return (int)GetValue(CountProperty); }
set { SetValue(CountProperty, value); }
}
// Using a DependencyProperty as the backing store for Count. This enables animation, styling, binding, etc...
public static readonly DependencyProperty CountProperty =
DependencyProperty.Register("Count", typeof(int), typeof(MainWindow), new UIPropertyMetadata(12));
private void button1_Click(object sender, RoutedEventArgs e)
{
vm.DependOne++;
vm.DependTwo++;
//I need to find way ...now here i have changed value of two variable.
//now it is possible to change Dependency Property
//Without here setting the value of dependency property
}
public class ViewModel : INotifyPropertyChanged
{
public ViewModel()
{
}
private int dependOne;
public int DependOne
{
get
{
return dependOne;
}
set
{
dependOne = value;
OnPropertyChanged("DependOne");
}
}
private int dependTwo;
public int DependTwo
{
get
{
return dependTwo;
}
set
{
dependTwo = value;
OnPropertyChanged("DependTwo");
}
}
#region -- INotifyPropertyChanged Members --
public event PropertyChangedEventHandler PropertyChanged;
public void OnPropertyChanged(string propertyNameArg)
{
PropertyChangedEventHandler handler = this.PropertyChanged;
if (handler != null)
{
handler(this, new PropertyChangedEventArgs(propertyNameArg));
}
}
#endregion
}
}
}
<Window x:Class="DependecnyProperty.MainWindow"
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 Background="LightGray" Text="{Binding Path=Count}" Height="23" HorizontalAlignment="Left" Margin="164,102,0,0" Name="textBox1" VerticalAlignment="Top" Width="120" />
<Button Content="Button" Height="23" HorizontalAlignment="Left" Margin="164,148,0,0" Name="button1" VerticalAlignment="Top" Width="120" Click="button1_Click" />
</Grid>
</Window>
namespace DependecnyProperty
{
/// <summary>
/// Interaction logic for MainWindow.xaml
/// </summary>
public partial class MainWindow : Window
{
public MainWindow()
{
InitializeComponent();
this.DataContext = this;
Count = dependOne + dependTwo;
}
int dependOne = 0;
int dependTwo = 0;
public int Count
{
get { return (int)GetValue(CountProperty); }
set { SetValue(CountProperty, value); }
}
// Using a DependencyProperty as the backing store for Count. This enables animation, styling, binding, etc...
public static readonly DependencyProperty CountProperty =
DependencyProperty.Register("Count", typeof(int), typeof(MainWindow), new UIPropertyMetadata(12));
private void button1_Click(object sender, RoutedEventArgs e)
{
dependOne = dependOne + 2;
dependTwo = dependTwo + 1;
//I need to find way ...now here i have changed value of two variable.
//now it is possible to change Dependency Property
//Without here setting the value of dependency property
}
}
}
namespace DependecnyProperty
{
/// <summary>
/// Interaction logic for MainWindow.xaml
/// </summary>
public partial class MainWindow : Window
{
ViewModel vm;
public MainWindow()
{
InitializeComponent();
this.DataContext = this;
vm = new ViewModel();
//this.DataContext = vm;
Count = vm.DependOne + vm.DependTwo;
}
public int Count
{
get { return (int)GetValue(CountProperty); }
set { SetValue(CountProperty, value); }
}
// Using a DependencyProperty as the backing store for Count. This enables animation, styling, binding, etc...
public static readonly DependencyProperty CountProperty =
DependencyProperty.Register("Count", typeof(int), typeof(MainWindow), new UIPropertyMetadata(12));
private void button1_Click(object sender, RoutedEventArgs e)
{
vm.DependOne++;
vm.DependTwo++;
//I need to find way ...now here i have changed value of two variable.
//now it is possible to change Dependency Property
//Without here setting the value of dependency property
}
public class ViewModel : INotifyPropertyChanged
{
public ViewModel()
{
}
private int dependOne;
public int DependOne
{
get
{
return dependOne;
}
set
{
dependOne = value;
OnPropertyChanged("DependOne");
}
}
private int dependTwo;
public int DependTwo
{
get
{
return dependTwo;
}
set
{
dependTwo = value;
OnPropertyChanged("DependTwo");
}
}
#region -- INotifyPropertyChanged Members --
public event PropertyChangedEventHandler PropertyChanged;
public void OnPropertyChanged(string propertyNameArg)
{
PropertyChangedEventHandler handler = this.PropertyChanged;
if (handler != null)
{
handler(this, new PropertyChangedEventArgs(propertyNameArg));
}
}
#endregion
}
}
}
namespace DependecnyProperty
{
///
///MainWindow.xaml的交互逻辑
///
公共部分类主窗口：窗口
{
公共主窗口（）
{
初始化组件（）；
this.DataContext=this；
计数=dependOne+dependTwo；
}
int dependOne=0；
int dependtow2=0；
公共整数计数
{
获取{return（int）GetValue（CountProperty）；}
set{SetValue（CountProperty，value）；}
}
//使用DependencyProperty作为计数的后备存储。这将启用动画、样式、绑定等。。。
公共静态只读DependencyProperty CountProperty=
DependencyProperty.Register（“计数”、typeof（int）、typeof（MainWindow）、新UIPropertyMetadata（12））；
私有无效按钮1\u单击（对象发送者，路由目标）
{
dependOne=dependOne+2；
dependTwo=dependTwo+1；
//我需要找到方法…现在我已经改变了两个变量的值。
//现在可以更改依赖项属性了
//在这里不设置dependency属性的值
}
}
}
<Window x:Class="DependecnyProperty.MainWindow"
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 Background="LightGray" Text="{Binding Path=Count}" Height="23" HorizontalAlignment="Left" Margin="164,102,0,0" Name="textBox1" VerticalAlignment="Top" Width="120" />
<Button Content="Button" Height="23" HorizontalAlignment="Left" Margin="164,148,0,0" Name="button1" VerticalAlignment="Top" Width="120" Click="button1_Click" />
</Grid>
</Window>
namespace DependecnyProperty
{
/// <summary>
/// Interaction logic for MainWindow.xaml
/// </summary>
public partial class MainWindow : Window
{
public MainWindow()
{
InitializeComponent();
this.DataContext = this;
Count = dependOne + dependTwo;
}
int dependOne = 0;
int dependTwo = 0;
public int Count
{
get { return (int)GetValue(CountProperty); }
set { SetValue(CountProperty, value); }
}
// Using a DependencyProperty as the backing store for Count. This enables animation, styling, binding, etc...
public static readonly DependencyProperty CountProperty =
DependencyProperty.Register("Count", typeof(int), typeof(MainWindow), new UIPropertyMetadata(12));
private void button1_Click(object sender, RoutedEventArgs e)
{
dependOne = dependOne + 2;
dependTwo = dependTwo + 1;
//I need to find way ...now here i have changed value of two variable.
//now it is possible to change Dependency Property
//Without here setting the value of dependency property
}
}
}
namespace DependecnyProperty
{
/// <summary>
/// Interaction logic for MainWindow.xaml
/// </summary>
public partial class MainWindow : Window
{
ViewModel vm;
public MainWindow()
{
InitializeComponent();
this.DataContext = this;
vm = new ViewModel();
//this.DataContext = vm;
Count = vm.DependOne + vm.DependTwo;
}
public int Count
{
get { return (int)GetValue(CountProperty); }
set { SetValue(CountProperty, value); }
}
// Using a DependencyProperty as the backing store for Count. This enables animation, styling, binding, etc...
public static readonly DependencyProperty CountProperty =
DependencyProperty.Register("Count", typeof(int), typeof(MainWindow), new UIPropertyMetadata(12));
private void button1_Click(object sender, RoutedEventArgs e)
{
vm.DependOne++;
vm.DependTwo++;
//I need to find way ...now here i have changed value of two variable.
//now it is possible to change Dependency Property
//Without here setting the value of dependency property
}
public class ViewModel : INotifyPropertyChanged
{
public ViewModel()
{
}
private int dependOne;
public int DependOne
{
get
{
return dependOne;
}
set
{
dependOne = value;
OnPropertyChanged("DependOne");
}
}
private int dependTwo;
public int DependTwo
{
get
{
return dependTwo;
}
set
{
dependTwo = value;
OnPropertyChanged("DependTwo");
}
}
#region -- INotifyPropertyChanged Members --
public event PropertyChangedEventHandler PropertyChanged;
public void OnPropertyChanged(string propertyNameArg)
{
PropertyChangedEventHandler handler = this.PropertyChanged;
if (handler != null)
{
handler(this, new PropertyChangedEventArgs(propertyNameArg));
}
}
#endregion
}
}
}
namespace DependecnyProperty
{
///
///MainWindow.xaml的交互逻辑
///
公共部分类主窗口：窗口
{
视图模型虚拟机；
公共主窗口（）
{
初始化组件（）；
this.DataContext=this；
vm=新的ViewModel（）；
//this.DataContext=vm；
Count=vm.DependOne+vm.dependtow2；
}
公共整数计数
{
获取{return（int）GetValue（CountProperty）；}
set{SetValue（CountProperty，value）；}
}
//使用DependencyProperty作为计数的后备存储。这将启用动画、样式、绑定等。。。
公共静态只读DependencyProperty CountProperty=
DependencyProperty.Register（“计数”、typeof（int）、typeof（MainWindow）、新UIPropertyMetadata（12））；
私有无效按钮1\u单击（对象发送者，路由目标）
{
vm.DependOne++；
vm.dependtow2++；
//我需要找到方法…现在我已经改变了两个变量的值。
//现在可以更改依赖项属性了
//在这里不设置dependency属性的值
}
公共类视图模型：INotifyPropertyChanged
{
公共视图模型（）
{
}
独立的私人公司；
公共int DependOne
{
得到
{
返回dependOne；
}
设置
{
dependOne=值；
不动产变更（“依赖”）；
}
}
私有int依赖于两个；
公共int依赖于2
{
得到
{
返回依赖项2；
}
设置
{
dependTwo=值；
OnPropertyChanged（“DependTwo”）；
}
}
#区域--INotifyPropertyChanged成员--
公共事件属性更改事件处理程序属性更改；
OnPropertyChanged上的公共无效（字符串propertyNameArg）
{
PropertyChangedEventHandler处理程序=this.PropertyChanged；
if（处理程序！=null）
{
处理程序（这是新的PropertyChangedEventArgs（propertyNameArg））；
}
}
#端区
}
}
}
//field
private int _dependOne;
//property
public int DependOne
{
get { return _dependOne; }
set {
_dependOne = value;
Count += value;
}
}
//Finally, use the property instead of the field
//dependOne = dependOne + 2;
DependOne += 2;
更新： 重要的是不要在Codebehind中更新ViewModel属性。相反，您可以调用ViewModel方法 XAML
<Window x:Class="WpfApplication1.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:Local="clr-namespace:WpfApplication1"
Title="MainWindow" Height="350" Width="525">
<StackPanel>
<StackPanel.Resources>
<Local:MyConverter x:Key="myConverter"/>
</StackPanel.Resources>
<TextBox>
<TextBox.Text>
<MultiBinding Converter="{StaticResource myConverter}">
<Binding Path="DependOne" Mode="OneWay"/>
<Binding Path="DependTwo" Mode="OneWay"/>
</MultiBinding>
</TextBox.Text>
</TextBox>
<Button Click="button1_Click">click</Button>
</StackPanel>
</Window>
我不知道什么是对你最好的解决方案。但是，其中之一是使用如下属性：
//field
private int _dependOne;
//property
public int DependOne
{
get { return _dependOne; }
set {
_dependOne = value;
Count += value;
}
}
//Finally, use the property instead of the field
//dependOne = dependOne + 2;
DependOne += 2;
更新： 重要的是不要在Codebehind中更新ViewModel属性。相反，您可以调用ViewModel方法 XAML
<Window x:Class="WpfApplication1.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:Local="clr-namespace:WpfApplication1"
Title="MainWindow" Height="350" Width="525">
<StackPanel>
<StackPanel.Resources>
<Local:MyConverter x:Key="myConverter"/>
</StackPanel.Resources>
<TextBox>
<TextBox.Text>
<MultiBinding Converter="{StaticResource myConverter}">
<Binding Path="DependOne" Mode="OneWay"/>
<Binding Path="DependTwo" Mode="OneWay"/>
</MultiBinding>
</TextBox.Text>
</TextBox>
<Button Click="button1_Click">click</Button>
</StackPanel>
</Window>
- 在视图模型中放置
和dependOnedependtow2 - 将INotifyPropertyChanged添加到视图模型
- 调用属性的setter时引发属性更改事件
- 使用将依赖项属性绑定到这两个视图模型属性
- 在视图模型中放置
和dependOnedependtow2 - 将INotifyPropertyChanged添加到视图模型
- 筹集财产