WPF调用控制 [英] WPF invoke a control

问题描述

我如何可以调用一个带参数的控制？我GOOGLE了这件事，但没有去哪里找！

How can i invoke a control with parameters? I've googled this up, but no where to find!

的调用UI线程

这是错误我得到：

更多信息：参数数量不匹配

Additional information: Parameter count mismatch.

和发生这种情况时，我做一个简单的检查一个TextBox控件的Text属性是否为空。这在WinForms的：

And this happens when i do a simple check whether the text property of a textbox control is empty or not. This works in WinForms:

if (this.textboxlink.Text == string.Empty)
   SleepThreadThatIsntNavigating(5000);

从这个跳跃如果行catch块，并表明我的消息。

It jumps from this if line to the catch block and shows me that message.

这是我如何尝试调用控件：

This is how i try to invoke the control:

//委托：
私人委托无效TBXTextChanger（串文本）;

// the delegate: private delegate void TBXTextChanger(string text);

private void WriteToTextBox(string text)
    {
        if (this.textboxlink.Dispatcher.CheckAccess())
        {
            this.textboxlink.Text = text;
        }

        else
        {
            this.textboxlink.Dispatcher.Invoke(
                System.Windows.Threading.DispatcherPriority.Normal,
                new TBXTextChanger(this.WriteToTextBox));
        }
    }

我在做什么错了？而且，由于我什么时候来调用控件时，我只是想读的内容？

What am I doing wrong? And since when do i have to invoke a control when i just want to read its content?

推荐答案

当你调用调用，你再没有指定你的论点（文本）。当调度员试图运行你的方法，它没有一个参数提供，你会得到一个异常

When you call Invoke, you're not specifying your argument (text). When the Dispatcher tries to run your method, it doesn't have a parameter to supply, and you get an exception.

尝试：

this.textboxlink.Dispatcher.Invoke(
     System.Windows.Threading.DispatcherPriority.Normal,
     new TBXTextChanger(this.WriteToTextBox), text);

---

如果您想从文本中读取的值中，一种选择是使用lambda：

---

If you want to read the value from a text box, one option is to use a lambda:

string textBoxValue = string.Empty;

this.textboxlink.Dispatcher.Invoke(DispatcherPriority.Normal, 
     new Action( () => { textBoxValue = this.textboxlink.Text; } ));

if (textBoxValue == string.Empty)
    Thread.Sleep(5000);

这篇关于WPF调用控制的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！