ios半透明遮罩层

简单的半透明遮罩层的生成，具体的alpha、样式可以根据自己的需求进行调节，代码如下:

#import "ViewController.h"

#define screenW self.view.bounds.size.width
#define screenH self.view.bounds.size.height
@interface ViewController ()

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
}
/**
 *  xib - button click - 生成半透明遮罩层
 */
- (IBAction)translucentMaskButtonClick:(UIButton *)sender {
    UIToolbar *toolbar = [[UIToolbar alloc]initWithFrame:CGRectMake(0, 0, screenW, screenH)];
    //样式
    toolbar.barStyle = UIBarStyleBlackTranslucent;//半透明
    //透明度
    toolbar.alpha = 0.5f;
    [self.view addSubview:toolbar];
}

@end