如何在运行时从超级视图中删除视图？

Posted 2023-02-26

【中文标题】如何在运行时从超级视图中删除视图？

【英文标题】：How to remove view from superview in run time?

【发布时间】：2016-09-26 10:43:37

【问题描述】：

基于互联网连接，我必须删除或添加子视图到超级视图。

我可以在运行时添加子视图。但不能从子视图中删除。

我试过这样

if ([statusString isEqualToString:@"Access Not Available"])
   view = [[UIView alloc]initWithFrame:CGRectMake(0, navigationView.frame.size.height, self.view.frame.size.width, 50)];
    [self.view addSubview:view];
    view.backgroundColor = [UIColor lightGrayColor];
else
    [[NSOperationQueue mainQueue] addOperationWithBlock:^ 

        [view removeFromSuperview];
    ];

但它并没有从超级视图中删除。

我该怎么做？

【问题讨论】：

除非view 为nil，否则这将起作用。

你能比“它不工作”更具体吗？结果如何？

@Arc676 查看我编辑的问题

您的子视图是UIViewController 吗？您可能正在寻找removeFromParentView()

您正在if 语句的真实块内创建视图。这意味着在 false 块中捕获的值是 nil。

【参考方案1】：

///in view did load
view_NoConnectn = [[UIView alloc]init];
[view_NoConnectn setBackgroundColor:[UIColor whiteColor]];
[view_NoConnectn setFrame:CGRectMake(0, frameHeight, frameWidth, 35)];

UIWindow* mainWindow = [[UIApplication sharedApplication] keyWindow];
 bool isFound=false;
for(UIView *child in [mainWindow subviews])

    if([child tag]==007)
        isFound=true;

 if(!isFound)

    [mainWindow addSubview: btn_setting];


[self.navigationController.view addSubview:view_NoConnectn];



////// whereever required
   if (show)
    if (self.navigationController.view.frame.size.height == frameHeight) 
        [UIView animateWithDuration:1.0 animations:^
            [self.navigationController.view setFrame:CGRectMake(self.navigationController.view.frame.origin.x, self.navigationController.view.frame.origin.y, self.navigationController.view.frame.size.width, frameHeight - 35)];
            [view_NoConnectn setFrame:CGRectMake(0, frameHeight-35, frameWidth, 35)];
            [self.view layoutIfNeeded];
        ];

    


else

    if (self.navigationController.view.frame.size.height != frameHeight) 
        [UIView animateWithDuration:1.0 animations:^
            [UIView animateWithDuration:0.8 animations:^
                [self.navigationController.view setFrame:CGRectMake(self.navigationController.view.frame.origin.x, self.navigationController.view.frame.origin.y, self.navigationController.view.frame.size.width, frameHeight)];
                [view_NoConnectn setFrame:CGRectMake(0, frameHeight, frameWidth, 35)];
                [self.view layoutIfNeeded];
            ];
         completion:^(BOOL finished) 
            [view_NoConnectn removeFromSuperview];
        ];