Cross-thread operation not valid解法

取得控制項文字

delegate string GetTextCallback(ComboBox cb);
private string GetText(ComboBox cb)
{
if (cb.InvokeRequired)
{
GetTextCallback stc = new GetTextCallback(GetText);
return this.Invoke(stc, new object[] { cb }).ToString ();
}
else
{
return cb.Text;
}
}

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設定控制項文字

delegate void SetTextCallback(string text);
private void SetText(string text)
{
if (txtbMeasureState.InvokeRequired)
{
SetTextCallback stc = new SetTextCallback(SetText);
this.Invoke(stc, new object[] { text  });
}
else
{
txtbMeasureState.Text = text;
}
}