(原)带圆角矩形边框的view

- (id)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self) 
    {
        CGFloat col[] = {1, 1, 1, 1}; //背景色.
        float offset = XXX_EdgeWidth;//边宽
        self.backgroundColor = XXX_EdgeColor;//边框色.
        
        //圆角
        self.layer.cornerRadius = 8.0f;
        self.layer.masksToBounds = YES;
        
        //弄出一个圆角的边
        CGRect frame2 = frame;
        frame2.origin.x = offset;
        frame2.origin.y = offset;
        frame2.size.width -= offset * 2;
        frame2.size.height -= offset * 2;
        CALayer *layer2 = [[CALayer alloc] init];
        layer2.frame = frame2;
        CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
        CGColorRelease(layer2.backgroundColor = CGColorCreate(colorSpace, col));
        CGColorSpaceRelease(colorSpace);
        layer2.cornerRadius = self.layer.cornerRadius - offset;
        self.layer.masksToBounds = YES;
        [self.layer addSublayer:layer2];
        [layer2 release];
    }
    return self;
}