如何从另一个线程访问和修改绑定到控件属性的依赖项属性?

问题描述

你好，

我想使用一个简单的例程:如果用户单击一个按钮，则该按钮消失，并且显示进度条.处理完成后，该按钮变为可见.

Hello,

I want to use a simple routine: if user clicks a button, then the button disappears and progress bar shows up. After processing is done, the button becomes visible.

viewModel.StartRendering();
string script = viewModel.LilyScript;
ThreadStart x = delegate
{
    Thread.Sleep(1000); // simulate long processing
    lily.ProcessScript(script);
    Dispatcher.Invoke(new Action(delegate
    {
        viewModel.LilyRenderOutput = lily.ImageSource;
        viewModel.EndRendering();
    }), DispatcherPriority.Normal);
};
Thread thr = new Thread(x);
thr.Name = "Renderowanie";
thr.Start();

viewModel具有dep属性，这些属性绑定到控件的属性.

The viewModel has dep properties which are bound to controls'' properties.

class MainWindowVM
{
...
// (obvious code omitted)
        public Visibility RenderingProgressBarVisibility...
        public static readonly DependencyProperty ...
        public Visibility PaintNotesButtonVisibility...
        public static readonly DependencyProperty ...
        public ImageSource LilyRenderOutput
        internal void StartRendering()
        {
            RenderingProgressBarVisibility = Visibility.Visible;
            PaintNotesButtonVisibility = Visibility.Hidden;
        }

        internal void EndRendering()
        {
            RenderingProgressBarVisibility = Visibility.Hidden;
            PaintNotesButtonVisibility = Visibility.Visible;
        }

}

我有一个异常调用线程无法访问该对象，因为其他线程拥有它.在线

I got an exception The calling thread cannot access this object because a different thread owns it. on line

viewModel.LilyRenderOutput = lily.ImageSource;

在xaml中:

In xaml:

<Image Source="{Binding LilyRenderOutput}" Stretch="None" />

有趣的事实:代码

Interesting fact: the code

Dispatcher.Invoke(new Action(delegate
{
    this.Title="abc";
}), DispatcherPriority.Normal);

确实有效.我使用错误的调度程序还是什么?我尝试过viewModel.Dispather没有成功.

感谢任何帮助.

does work. Do I use a wrong dispatcher or what? I tried viewModel.Dispather with no success.

Any help appreciated.

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