clearing screen after CGContextDrawImage

I am trying for a image relaterd i-phone application.I am using a line of code

    CGContextDrawImage(context1, CGRectMake(0, 0, width, height), imageRef);

I am working with multiple images.So i want to clear the screen after this .Any bui开发者_开发知识库lt in function using for this (Like in C we can use cleardevice in graphics).Any help appreciating.

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Check out CGContextFillRect - just set the rect to be the whole view and the brush to be solid white :)

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For example, to clear the image you just drew with white :

const CGFloat white[] = {1.0f, 1.0f, 1.0f, 1.0f};
CGContextSetFillColor(context1, white);
CGContextFillRect(context1, CGRectMake(0, 0, width, hight));