代码如下：
[button setBackgroundImage:[UIImage imageNamed:@"pic1"] forState:UIControlStateNormal]
[button setBackgroundImage:[UIImage imageNamed:@"pic2"] forState:UIControlStateHighlighted];
如果想使用纯色为背景色
可以使用如下代码：
-(UIImage*) imageWithColor:(UIColor*)color
{
CGRect rect = CGRectMake(0.0f, 0.0f, 1.0f, 1.0f);
UIGraphicsBeginImageContext(rect.size);
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextSetFillColorWithColor(context, [color CGColor]);
CGContextFillRect(context, rect);
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return image;
}
