drawRect：rect如何调用此方法，我正在绘制一个字符串

Question

-(void)drawRect:(CGRect)rect
{   
    CGContextRef  context = UIGraphicsGetCurrentContext();
    CGContextSelectFont(context, "Arial", 24, kCGEncodingFontSpecific);
    CGContextSetTextPosition(context,80,80);
    CGContextShowText(context, "hello", 6);
    //not even this works
    CGContextShowTextAtPoint(context, 1,1, "hello", 6);
}

I want to know how to call the above method, I have pasted the above code into the implementation file, but don't know why it's not called when I execute the project.

Does anyone know why this could be?

Answer 1

setNeedsDisplay should do that for you, here is a link link text

The methods is also called when the view first displays...

Answer 2

Finally I got the anser, just take a new class and inherit the class with UIView instead of NSobject,

This class will give us UIView object and it will also contain the drawRect method inbuilt.

so this is How i done. it :)