private delegate void SetTextHandle(string id, string value);private void ThreadSetText(string id, string value){this.Controls.Find(id, true)[0].Text = value;}private void SetText(string id, string value){if (this.InvokeRequired){this.Invoke(new SetTextHandle(ThreadSetText), new object[] { id, value });}else{ThreadSetText(id, value);}}

// the canonical form (C# consumer)public delegate void ControlStringConsumer(Control control, string text);  // defines a delegate typepublic void SetText(Control control, string text) {if (control.InvokeRequired) {control.Invoke(new ControlStringConsumer(SetText), new object[]{control, text});  // invoking itself} else {control.Text=text;      // the "functional part", executing only on the main thread}
}

public static class ControlHelpers
{public static void InvokeIfRequired<T>(this T control, Action<T> action) where T : ISynchronizeInvoke{if (control.InvokeRequired){control.Invoke(new Action(() => action(control)), null);}else{action(control);}}
}

theLabel.Invoke(new Action(() => theLabel.Text = "hello world from worker thread!"));

public static void InvokeIfRequired(this Control control, MethodInvoker action)
{if (control.InvokeRequired) {control.Invoke(action);} else {action();}
}

richEditControl1.InvokeIfRequired(() =>
{// Do anything you want with the control hererichEditControl1.RtfText = value;RtfHelpers.AddMissingStyles(richEditControl1);
});

public static void InvokeIfRequired(this ISynchronizeInvoke obj,MethodInvoker action)
{if (obj.InvokeRequired) {var args = new object[0];obj.Invoke(action, args);} else {action();}
}

public static void InvokeIfRequired(this Control c, Action<Control> action)
{if(c.InvokeRequired){c.Invoke(new Action(() => action(c)));}else{action(c);}
}

public static void InvokeIfRequired<T>(this T c, Action<T> action) where T : Control

object1.InvokeIfRequired(c => { c.Visible = true; });