WPF 调用控件

发布于 2024-09-29 03:56:53 字数 1059 浏览 0 评论 0原文

如何使用参数调用控件？我用谷歌搜索过这个，但无处可寻！

这是我得到的错误：

附加信息：参数计数不匹配。

当我简单检查文本框控件的文本属性是否为空时，就会发生这种情况。这在 WinForms 中有效：

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

它从 if 行跳转到 catch 块并向我显示该消息。

这就是我尝试调用控件的方式：

// 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));
    }
}

我做错了什么？当我只想读取控件的内容时，从什么时候开始我必须调用该控件？

原文

How can I invoke a control with parameters? I've googled this up, but nowhere to find!

invoke ui thread

This is the error i get:

Additional information: Parameter count mismatch.

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);

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

This is how i try to invoke the control:

// 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));
    }
}

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

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森罗 2024-10-06 03:56:53

当您调用 Invoke 时，您没有指定您的参数 (text)。当调度程序尝试运行您的方法时，它没有要提供的参数，并且您会收到异常。

尝试：

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

如果您想从文本框中读取值，一种选择是使用 lambda：

string textBoxValue = string.Empty;

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

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

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.

Try:

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

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);

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