半透明弹出选择窗时屏蔽导航栏

 chooseView = [[UIView alloc]initWithFrame:CGRectMake(0, 0, [DMDevceManager screenWidth], [DMDevceManager screenHeight])];
    
    chooseView.backgroundColor = [[UIColor blackColor] colorWithAlphaComponent:0.75];
//以下方法来自cocoaChina的135790的回帖
    UIWindow* currentWindow = [UIApplication sharedApplication].keyWindow;
    [currentWindow addSubview:chooseView];

效果如图:

记录个小方法.