滚动视图不显示 UIView 和 UIImage

Posted 2023-02-27

【中文标题】滚动视图不显示 UIView 和 UIImage

【英文标题】：Scrollview Does not Show with UIView and UIImage

【发布时间】：2014-10-01 04:39:08

【问题描述】：

我有：

UIView 包含一个 ImageView 在此 UIView 中添加 UIScrollView 以启用 Scroll（不起作用） 我有一个 AlertView 来弹出这个 UIView 我添加了 UIImageView 和 UIScrollView 作为 UIView 的子视图

每次我运行代码时，都没有滚动视图存在的迹象。我不知道为什么。

代码如下：

- (void) handleImageTap:(UIGestureRecognizer *)gestureRecognizer 



    //create image

    UIImageView *imageView = [[UIImageView alloc] initWithFrame:CGRectMake(10, 10, 500, 500)];



    //create a scrollview to contain the uiview above

    UIScrollView* scrollview=[[UIScrollView alloc]initWithFrame:CGRectMake(0,0,320,480)];

    scrollview.showsVerticalScrollIndicator=YES;

    scrollview.scrollEnabled=YES;

    scrollview.userInteractionEnabled=YES;

    [scrollview setDelegate:self];

    [scrollview setBouncesZoom:YES];



    scrollview.contentSize = CGSizeMake(500,500);

    //create a view to show picture

    UIView *demoView = [[UIView alloc] init];

    if(gestureRecognizer.view == _firstImageView)

        UIImage *image = [UIImage imageNamed:_photoDetailModel[1]];

        [imageView setImage:image];



        CGSize imageSize = imageView.image.size;

        [demoView setFrame: CGRectMake(0, 0, 290, 200)];

//        [demoView setFrame: CGRectMake(0, 0,imageSize.width, imageSize.height)];

    else

        UIImage *image = [UIImage imageNamed:_photoDetailModel[2]];

        [imageView setImage:image];



        CGSize imageSize = imageView.image.size;

        [demoView setFrame: CGRectMake(0, 0, 290, 200)];

    

    //add imageview

    [demoView addSubview:imageView];



    //add scollview

    [demoView addSubview:scrollview];



    //create a pop up view to contain the above uiview

    Customios7AlertView *alertView = [[CustomIOS7AlertView alloc] init];



    // Add some custom content to the alert view

    [alertView setContainerView: demoView];



    // Modify the parameters

    [alertView setButtonTitles:[NSMutableArray arrayWithObjects:@"Close", nil]];



    // You may use a Block, rather than a delegate.

//    [alertView setOnButtonTouchUpInside:^(CustomIOS7AlertView *alertView, int buttonIndex) 

//        NSLog(@"Block: Button at position %d is clicked on alertView %d.", buttonIndex, (int)[alertView tag]);

//        [alertView close];

//    ];



    [alertView setUseMotionEffects:true];



    // And launch the dialog

    [alertView show];

【参考方案1】：

现在您正在将scrollview 添加到demoView。应该是相反的。

//add scrollview
[scrollview addSubview:demoView];

如果您希望 scrollview 成为警报视图的 contentView，您还希望将其设置为警报视图，而不是 demoView。

// Add some custom content to the alert view
[alertView setContainerView:scrollview];

您的最终视图层次结构应如下所示：

| AlertView
| --- ScrollView
| ------- DemoView
| ----------- ImageView

【讨论】：

你能告诉我在这种情况下如何启用缩放吗？我尝试：scrollView.delegate = alertView;然后添加这个滚动视图委托方法：但它不起作用。

除非您将警报视图子类化，否则您将希望将委托设置为视图控制器。然后设置最小和最大缩放比例。最后实现viewForZoomingInScrollView方法，返回demoView。

我尝试这样做，但我没有调用 viewForZoomingInScrollView，这是我在 github 上的代码：github.com/anthony1810/PhotoViewer。

返回demoView 而不是imageView。

我只是打开它并更改为demoView，它仍然无法正常工作:(