IOS 平铺图片

UIImage *bgImg = [UIImage imageNamed:@"图集背景@2x_33"];
    UIColor *color = [[UIColor alloc] initWithPatternImage:bgImg];
    UIView *bg = [[UIView alloc] initWithFrame:self.view.frame];
    [bg setBackgroundColor:color];
    [self.view addSubview:bg];