how to clear the graphics(rectangle shape) in picturebox

问题

i created rectangle shape user control and i am using this user control in my application.In my application i am processing a image for different operations such as reading barcode from images etc.Here i have two possibility of processing a image, one is processing entire image and another is processing selected part of the image,i am selecting the specific part of the image using rectangle shape(this is user-control).so i have given two option in my GUI for this purpose one is Entire image and another is Rectangle.if i used rectangle first time for selection and next time i selected entire image,then previously selected rectangle shape was not removed from the picturebox.So how can i clear this Rectangle shape from my picturebox? The below image shows the Rectangle shape in picturebox

回答1:

Try this Graphics.clear(); or this.Invalidate();

来源：https://stackoverflow.com/questions/10442279/how-to-clear-the-graphicsrectangle-shape-in-picturebox