如何重新加载当前的 UIView

Question

我有一个从主视图调用的方法，该方法正在设置我想在滚动视图中显示的图像的图像名称。

 - (void)loadImage:(NSString *)myImageName
    {
        if (myImageName == @"one") {
            imageName = myImageName;
        }
        if (myImageName == @"two") {
            imageName = myImageName;
        }
        if (myImageName == @"three") {
            imageName = myImageName;
        }

        //Reloads view here???
    }

我正在像这样在我的 viewdidload 方法中加载图像

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.

    //Create scrollview
    scrollView = [[UIScrollView alloc] initWithFrame:[[UIScreen mainScreen] applicationFrame]];
    scrollView.delegate = self;
    scrollView.bounces = NO;

    //Create scrollviewimage
    if (imageName == @"one") {
        image = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"ha.png"]];
    }
    if (imageName == @"two") {
        image = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"haha.png"]];
    }
    if (imageName == @"three") {
        image = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"hahaha.png"]];
    }



    containerView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 320, 550)];
    //Add subview
    [containerView addSubview:image];
    //initViews
    scrollView.contentSize = containerView.frame.size;
    [scrollView addSubview:containerView];

    //scrolling
    scrollView.minimumZoomScale = 1.0;
    scrollView.maximumZoomScale = 31.0;
    [scrollView setZoomScale:scrollView.minimumZoomScale];

    //highrachy
    [self.view addSubview:scrollView];

}

当我从 tableviewcell 选择中设置父视图的图像名称时会发生什么我将 nsstring 传递到 loadImage.. 然后加载图像在 viewdidload 中设置名称.. 但是发生的事情是只有第一个选择剂量任何东西..所以你总是会看到你选择的第一张图片..所以如果你选择第二张图片，你选择的每隔一个图片就会显示第二张图片..

任何帮助都会很棒。

这是父视图单元格选择的样子

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
    //Sets the back button for the new view that loads (this overrides the usual parentview name with "Back")
    self.navigationItem.backBarButtonItem = [[UIBarButtonItem alloc] initWithTitle:@"Back" style: UIBarButtonItemStyleBordered target:nil action:nil];

    if (!self.detailViewController) {
        self.detailViewController = [[ICDDetailViewController alloc] initWithNibName:@"ICDDetailViewController" bundle:nil];

        if (indexPath.section == 0) {
            _detailViewController.imageName = @"one";
            //        NSLog(@"%@", indexPath);
        }
        if (indexPath.section == 1) {
            _detailViewController.imageName = @"two";
            //        NSLog(@"%@", indexPath);
        }
        if (indexPath.section == 2) {
            _detailViewController.imageName = @"three";
            //        NSLog(@"%@", indexPath);
        }
    }
    [self.navigationController pushViewController:self.detailViewController animated:YES];

}

Answer 1

不要使用 myImageName == @"three"。有一种比较字符串的特殊方法。

试试这个：

if ([myImageName isEqualToString:@"three"]) {
    [image setImage:[UIImage imageNamed:myImageName]];
}

如果有文件扩展名，请执行以下操作：

NSString *imagePath = [NSString stringWithFormat:@"%@.png",myImageName];
[image setImage:[UIImage imageNamed:imagePath]];

顺便说一句，您仍在发布您在其他问题中的旧代码。您将 detailView 保留在原始类中，而不是发布和创建新实例。取出 if (!detailView) 语句。

更新：唯一的其他选择是将分配从大 if( ) 块中取出。

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
    //Sets the back button for the new view that loads (this overrides the usual parentview name with "Back")
    self.navigationItem.backBarButtonItem = [[UIBarButtonItem alloc] initWithTitle:@"Back" style: UIBarButtonItemStyleBordered target:nil action:nil];

    if (!self.detailViewController) {
        self.detailViewController = [[ICDDetailViewController alloc] initWithNibName:@"ICDDetailViewController" bundle:nil];


    //MY CHANGES HERE:
    //If you left these if () statements inside the original code, they would never
    //fire if the detailView was already instantiated once.  Does this make sense?
    }  // <--- moved the bracket up here
        if (indexPath.section == 0) {
            _detailViewController.imageName = @"one";
            //        NSLog(@"%@", indexPath);
        }
        if (indexPath.section == 1) {
            _detailViewController.imageName = @"two";
            //        NSLog(@"%@", indexPath);
        }
        if (indexPath.section == 2) {
            _detailViewController.imageName = @"three";
            //        NSLog(@"%@", indexPath);
        }
    //}  <--- commented this one out
    [self.navigationController pushViewController:self.detailViewController animated:YES];

}

唯一的另一种方法是：

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
    //Sets the back button for the new view that loads (this overrides the usual parentview name with "Back")
    self.navigationItem.backBarButtonItem = [[UIBarButtonItem alloc] initWithTitle:@"Back" style: UIBarButtonItemStyleBordered target:nil action:nil];
    //commented out the next line, don't need to check to see if it's already present
    //just create a new instance to push on the stack
    //if (!self.detailViewController) {
        self.detailViewController = [[ICDDetailViewController alloc] initWithNibName:@"ICDDetailViewController" bundle:nil];

        if (indexPath.section == 0) {
            _detailViewController.imageName = @"one";
            //        NSLog(@"%@", indexPath);
        }
        if (indexPath.section == 1) {
            _detailViewController.imageName = @"two";
            //        NSLog(@"%@", indexPath);
        }
        if (indexPath.section == 2) {
            _detailViewController.imageName = @"three";
            //        NSLog(@"%@", indexPath);
        }
    //} <--- get rid of this bracket since the original if () was commented out
    [self.navigationController pushViewController:self.detailViewController animated:YES];

}

Answer 2

听起来您从未发布过您的 UIScrollView 实例。因此，当您第二次重用它时， viewDidLoad 不会再次被调用。这意味着您的“图像”变量永远不会被重新分配新图像。

要检查是否是这种情况，请尝试在 viewDidLoad 方法中调用 NSLog 并查看它是否在您第二次从 tableViewCell 中选择时被调用。

如果是这种情况，有几个选项可以修复它。你在使用 ARC 吗？

Answer 3

您是否尝试过仅更新UIImageView？

- (void)loadImage:(NSString *)myImageName
{
    if (myImageName == @"one") {
        imageName = myImageName;
    }
    if (myImageName == @"two") {
        imageName = myImageName;
    }
    if (myImageName == @"three") {
        imageName = myImageName;
    }

    [image setImage:[UIImage imageNamed:imageName];
}