.NET Resize Event: get old size?

Question

I added a resize event to one of my widgets, which looks like this:

void glControl_Resize(object sender, EventArgs e) { 

Is there a way to get the old widget size (before resizing)? Maybe I can give e something that will give me more information? Or should I just save it during this event?

Answer 1

Yes, just keeping track of the old size in the class field is a simple solution. For example:

 Size mOldSize; private void glControl_Resize(object sender, EventArgs e) { if (mOldSize != Size.Empty && mOldSize != glControl.Size) { // do something... } mOldSize = glControl.Size; } 

Answer 2

By convention, you should add an OnResizing event that fires only when it is about to change, but has not changed, and then you OnResize after changing it. You will get the old value from your EventArg in the OnResizing event.

Edit:

Are you creating your own event or activating one of the included controls?

If you are making your own event, you can get EventArg and do something like ResizeEventArg , which includes the size of the thing you want.

I would use ResizeEventArg for the Resize and OnResizing , and still follow what I said earlier.

Or, if you know what type of control it is, you can apply an Object sender to the type, and then read the property.