C# WinForm: Simulate Right Mouse Click

[nuhfeken]

We have a C# winform that uses the MVP design pattern for the user interface. For reasons I'd rather not explain we need to simulate a right mouse click on a specific control to deactivate the control. I found code that almost does what we need.

[DllImport("user32.dll")]
private static extern void mouse_event(
UInt32 dwFlags, // motion and click options
UInt32 dx, // horizontal position or change
UInt32 dy, // vertical position or change
UInt32 dwData, // wheel movement
IntPtr dwExtraInfo // application-defined information
);

public static void PerformSingleRightMouseClick(Point cursorLocation)
{
const UInt32 MOUSEEVENTF_RIGHTDOWN = 0x0008; /* right button down */
const UInt32 MOUSEEVENTF_RIGHTUP = 0x0010; /* right button up */

UInt32 x = Convert.ToUInt32(cursorLocation.X);
UInt32 y = Convert.ToUInt32(cursorLocation.Y);

mouse_event(MOUSEEVENTF_RIGHTDOWN, x, y, 0, new IntPtr());
mouse_event(MOUSEEVENTF_RIGHTUP, x, y, 0, new IntPtr());
}

When PerformSingleRightMouseClick is called, it does simulate a right mouse click but there is one problem. It performs the mouseclick from wherever the mouse is currently. So if the user clicks outside of the form, say on the desktop, the windows popup menu displays.

How can I get it so the coordinates I pass to the mouse_event actually use the position I'm passing in.

I tried passing both Cursor.Position and Control.ClientToPoint and they both still did the same thing.

[Plater]

you could try picking a static number like (10,10) and see if it performs the click 10,10 from the top left corner of screen, top left corner of window or top left corner of a control?

[nuhfeken]

Well, I learned some more yesterday on this. I still haven't fixed the underlying problem which is a control won't release the mouse, which forces someone to click any other control (other than the one already selected) twice. Once to activate or set the focus to it, again to click the control. That is the underlying problem which I had hoped to fix by simulating a right mouse click (a horrible solution but the only one that seemed to work). I tried setting control properties, tried changing the focus, nothing seems to work. Except the right click. The real problem is a call to Application.DoEvents in the middle of a controls UI events. But it is required to keep the circular wait cursor moving.

When I called the above "mouse_event", the x,y coordinates are meaningless unless you add MOUSEEVENTF_MOVE to the code like this.

public static void PerformSingleRightMouseClick(/*Point cursorLocation*/)
{
const UInt32 MOUSEEVENTF_RIGHTDOWN = 0x0008; /* right button down */
const UInt32 MOUSEEVENTF_RIGHTUP = 0x0010; /* right button up */
//const UInt32 MOUSEEVENTF_ABSOLUTE = 0x8000;
const UInt32 MOUSEEVENTF_MOVE = 0x0001;

UInt32 x = Convert.ToUInt32(cursorLocation.X);
UInt32 y = Convert.ToUInt32(cursorLocation.Y);

mouse_event(MOUSEEVENTF_RIGHTDOWN | MOUSEEVENTF_MOVE , 0, 0, 0, new IntPtr());
mouse_event(MOUSEEVENTF_RIGHTUP | MOUSEEVENTF_MOVE , 0, 0, 0, new IntPtr());
}

This will move the mouse to whatever the specified co-ordinates are. This really isn't the desired behavior I was seeking. I just want to instantly perform a right click at the exact time the user clicks the control.

I also tried
[DllImportAttribute("user32.dll")]
public static extern bool ReleaseCapture();

Hoping this would release the mouse capture but it didn't seem to fix the problem either.

[Plater]

I know you said not to ask, but if you're using mvc...why are you even bothering to come into the .NET world.
That's like buying a $4000 couch so you can grind your muddy shoes on it.

[nuhfeken]

Well, because I inherited the project. That is why. LOL!

In their defense, the application is a rather complex, large application (UI layout is similer to Microsoft Outlook) with a ton of controls and no popup forms/separate forms. Minus some minor complexity and the occasional weird problem like this one I think the alternative might of been even scarier. A spaghetti-code nightmare with insane amounts of duplicate code, near identical forms and controls everywhere.

[chagbert]

You need run your events under a different THREAD and use an await async to get the results from it (if you need results)