How to enable form button after process has exited?
I have an windows application developed using C#. In this application, I am creating one process. I want to enable and disable few buttons when Process_Exited() event occures. In Process_Exited() method, I have written code to enable buttons but at runtime I get error as
"Cross-thread operation not valid: Control 'tabPage_buttonStartExtraction' accessed from a thread other than the thread it was created on."
My code snippet is :
void rinxProcess_Exited(object sender, EventArgs e)
{
tabPage_buttonStartExtraction.Enabled = true;
tabPageExtraction_StopExtractionBtn.Enabl开发者_如何学Goed = false;
}
Can anyone suggest how to make this possible?
Move the enable/disable lines in a separate method and call that method from rinxProcess_Exited using Control.Invoke method.
You're attempting to change the UI from a different thread. Try something like this;
private void SetText(string text)
{
// InvokeRequired required compares the thread ID of the
// calling thread to the thread ID of the creating thread.
// If these threads are different, it returns true.
if (this.textBox1.InvokeRequired)
{
SetTextCallback d = new SetTextCallback(SetText);
this.Invoke(d, new object[] { text });
}
else
{
this.textBox1.Text = text;
}
}
You shouldn't be doing much work on the UI from another thread, as the invocations are quite expensive.
Source: http://msdn.microsoft.com/en-us/library/ms171728.aspx
You must make UI changes on the UI thread. See this question for more details.
Here's the solution applied to your example:
void rinxProcess_Exited(object sender, EventArgs e)
{
if (this.InvokeRequired)
{
this.Invoke((Action)(() => ProcessExited()));
return;
}
ProcessExited();
}
private void ProcessExited()
{
tabPage_buttonStartExtraction.Enabled = true;
tabPageExtraction_StopExtractionBtn.Enabled = false;
}
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