Lee's approach can be simplified further
public static void InvokeIfRequired(this Control control, MethodInvoker action)
{
// See Update 2 for edits Mike de Klerk suggests to insert here.
if (control.InvokeRequired) {
control.Invoke(action);
} else {
action();
}
}
And can be called like this
richEditControl1.InvokeIfRequired(() =>
{
// Do anything you want with the control here
richEditControl1.RtfText = value;
RtfHelpers.AddMissingStyles(richEditControl1);
});
There is no need to pass the control as parameter to the delegate. C# automatically creates a closure.
UPDATE:
According to several other posters Control
can be generalized as ISynchronizeInvoke
:
public static void InvokeIfRequired(this ISynchronizeInvoke obj,
MethodInvoker action)
{
if (obj.InvokeRequired) {
var args = new object[0];
obj.Invoke(action, args);
} else {
action();
}
}
DonBoitnott pointed out that unlike Control
the ISynchronizeInvoke
interface requires an object array for the Invoke
method as parameter list for the action
.
UPDATE 2
Edits suggested by Mike de Klerk (see comment in 1st code snippet for insert point):
// When the form, thus the control, isn't visible yet, InvokeRequired returns false,
// resulting still in a cross-thread exception.
while (!control.Visible)
{
System.Threading.Thread.Sleep(50);
}
See ToolmakerSteve's comment below for concerns about this suggestion.
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