C# WPF&;SimpleMVVM:将新viewmodel绑定到视图
请注意,此问题专门针对SimpleMVVM及其ViewModelLocator的使用。 我有这样的视图设置:C# WPF&;SimpleMVVM:将新viewmodel绑定到视图,c#,wpf,data-binding,viewmodellocator,simple-mvvm,C#,Wpf,Data Binding,Viewmodellocator,Simple Mvvm,请注意,此问题专门针对SimpleMVVM及其ViewModelLocator的使用。 我有这样的视图设置: <UserControl x:Class="CallTracker.WPF.Views.CallUserControl" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/w
<UserControl x:Class="CallTracker.WPF.Views.CallUserControl"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
DataContext="{Binding Source={StaticResource Locator}, Path=CallViewModel}">
<StackPanel>
<TextBlock Text="{Binding GreetingText}" />
</StackPanel>
</UserControl>
在执行过程中,我试图创建一个新的CallUserControl来使用,但是使用Snoops,我可以看到CallUserControl的datacontext没有绑定到viewmodel(Snoops中的datacontext表示null)
通过代码,我可以看到CallViewModel正在创建并分配给定位器中的对象,但是UserControl的datacontext没有绑定到这个新创建的对象
我正在创建新的CallViewModel,如下所示:
private void NewCall()
{
MessageBox.Show("NewCallCommand executed.");
// Only start a new call if one doesn't currently exist
if((App.Current.Resources["Locator"] as ViewModelLocator).CallViewModel == null)
{
CurrentCallViewModel = new CallViewModel();
}
}
....
/// <summary>
/// Current MainContentViewModel
/// </summary>
public CallViewModel CurrentCallViewModel
{
get
{
//Visibility _visible = (new ViewModelLocator()).CallViewModel == null ? Visibility.Collapsed : Visibility.Visible;
return (App.Current.Resources["Locator"] as ViewModelLocator).CallViewModel;
}
set
{
if (this._CurrentCallViewModel != value)
{
this._CurrentCallViewModel = value;
(App.Current.Resources["Locator"] as ViewModelLocator).CallViewModel = value;
NotifyPropertyChanged(m => m.CurrentCallViewModel);
}
}
}
private CallViewModel _CurrentCallViewModel = null;
private void NewCall()
{
Show(“NewCallCommand已执行”);
//仅当当前不存在新呼叫时才开始新呼叫
if((App.Current.Resources[“Locator”]作为ViewModelLocator.CallViewModel==null)
{
CurrentCallViewModel=新的CallViewModel();
}
}
....
///
///当前MainContentViewModel
///
公共调用视图模型CurrentCallViewModel
{
收到
{
//可见性_visible=(新的ViewModelLocator()).CallViewModel==null?可见性。折叠:可见性。可见;
返回(App.Current.Resources[“Locator”]作为ViewModelLocator);
}
设置
{
如果(此._CurrentCallViewModel!=值)
{
这。_CurrentCallViewModel=值;
(App.Current.Resources[“Locator”]作为ViewModelLocator);
NotifyPropertyChanged(m=>m.CurrentCallViewModel);
}
}
}
私有CallViewModel _CurrentCallViewModel=null;
您知道为什么这个新的ViewModel不会绑定到新模型吗?是否存在类似于NotifyPropertyChanged的机制,我必须从定位器调用该机制才能绑定对象?我在这里暗中拍摄了一张完整的照片……您已经设置了
CurrentCallViewModel=new CallViewModel()
,但您是否也需要将(App.Current.Resources[“Locator”]设置为ViewModelLocator)。CallViewModel=CurrentCallViewModel
?我想您需要调用CallViewModel属性的setter中更改的属性。我应该知道我正在调用(App.Current.Resources[“Locator”]作为ViewModelLocator).CallViewModel=值:在CurrentCallViewModel的属性设置器中。我已经用属性设置器更新了OP。
private void NewCall()
{
MessageBox.Show("NewCallCommand executed.");
// Only start a new call if one doesn't currently exist
if((App.Current.Resources["Locator"] as ViewModelLocator).CallViewModel == null)
{
CurrentCallViewModel = new CallViewModel();
}
}
....
/// <summary>
/// Current MainContentViewModel
/// </summary>
public CallViewModel CurrentCallViewModel
{
get
{
//Visibility _visible = (new ViewModelLocator()).CallViewModel == null ? Visibility.Collapsed : Visibility.Visible;
return (App.Current.Resources["Locator"] as ViewModelLocator).CallViewModel;
}
set
{
if (this._CurrentCallViewModel != value)
{
this._CurrentCallViewModel = value;
(App.Current.Resources["Locator"] as ViewModelLocator).CallViewModel = value;
NotifyPropertyChanged(m => m.CurrentCallViewModel);
}
}
}
private CallViewModel _CurrentCallViewModel = null;