修改UIAlert样式的代码

修改UIAlert样式的代码 

UIImage *theImage = [UIImage imageNamed:@"alert_big.png"];    

theImage = [theImage stretchableImageWithLeftCapWidth:0. topCapHeight:0.];

CGSize theSize = [alertShow frame].size;

UIGraphicsBeginImageContext(theSize);    

[theImage drawInRect:CGRectMake(0, 0, theSize.width, theSize.height)];    

theImage = UIGraphicsGetImageFromCurrentImageContext();    

UIGraphicsEndImageContext();

alertShow.layer.contents = (id)[theImage CGImage];