WPF中的线程错误（另一个线程拥有它。） [英] Thread error in WPF (a different thread owns it.)

问题描述

我正在尝试从WPF中的另一个类访问文本框。该方法由线程启动。当我尝试设置文本框值时会出现错误



WindowsBase.dll中出现未处理的System.InvalidOperationException类型异常



附加信息：调用线程无法访问此对象，因为另一个线程拥有它。



方法调用：

线程tScan =  new 线程（MyClass.Start）; 

方法从MyClass.Start（）方法调用的状态，例如，

  public   static   void  StatusPrint（）
 {
 Instance.txtReport.Text =  将在此处设置值。< /跨度>; 
} 

因为我是WPF的新手所以，需要你的帮助来摆脱这个。



我尝试了什么：



我试过这样做。

  public   static   void  StatusPrint（）
 {
 System.Windows.Threading.Dispatcher.CurrentDispatcher.BeginInvoke（ new  ThreadStart（（） = >  Instance.txtReport.Text =   value将在这里设置。））; 
} 

这里实例是在MainWindow中声明的静态变量class已启动到此。

这里我没有收到任何运行时错误，但它只是没有执行。

解决方案

为什么 ThreadStart 在 Dispatcher.CurrentDispatcher 中？您不想启动新线程。将 ThreadStart 更改为操作，它应该可以。

我有一个扩展名我喜欢在这种情况下使用的方法：

  public   static   void  BeginInvokeIfRequired（此调度程序调度程序，操作操作）
 {
  if （operation ==  null ） return ; 
  if （dispatcher.CheckAccess（））
 {
 action（）; 
} 
  else  
 {
 dispatcher.BeginInvoke（action）; 
} 
} 

要调用它，您需要做的就是：

 Application.Current.Dispatcher.BeginInvokeIfRequired（（）=> Instance.txtReport.Text =  将在此处设置值。）; 

Hi,

I am trying to access the textbox from another class in WPF. The method has been initiated by a thread. And when I am trying to set the textbox value it is getting an error

An unhandled exception of type 'System.InvalidOperationException' occurred in WindowsBase.dll

Additional information: The calling thread cannot access this object because a different thread owns it.

method called:

Thread tScan = new Thread(MyClass.Start);

method Statusprint called from MyClass.Start() method like,

public static void StatusPrint()
        {
            Instance.txtReport.Text = "value will set here.";
        }

As I am new in WPF so, need your help to get rid of this.

What I have tried:

I tried to do this way.

public static void StatusPrint()
        {
            System.Windows.Threading.Dispatcher.CurrentDispatcher.BeginInvoke(new ThreadStart(() => Instance.txtReport.Text = "value will set here."));
        }

here Instance is a static variable declared in MainWindow class initiated to this.
here I am not getting any runtime error but it is just not executing.

解决方案

Why ThreadStart inside the Dispatcher.CurrentDispatcher? You don't want to start a new thread. Change ThreadStart to Action and it should work.

I have an extension method that I like to use in this case:

public static void BeginInvokeIfRequired(this Dispatcher dispatcher, Action operation)
{
  if (operation== null) return;
  if (dispatcher.CheckAccess())
  {
    action();
  }
  else
  {
    dispatcher.BeginInvoke(action);
  }
}

To call it, all you need to do is this:

Application.Current.Dispatcher.BeginInvokeIfRequired(()=>Instance.txtReport.Text = "value will set here.");

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