如何刪除自定義UICollectionViewCell

Question

我真的陷入了這個問題。 我有一個使用自定義單元格的UICollectionView（在用戶按下按鈕后添加了單元格）

每個單元格都有一個按鈕以及一些其他不相關的控件。 點擊該按鈕后，我希望刪除該單元格。

這是我當前的問題順序：

• 用戶點擊UICollectionView下面的按鈕以進入ViewController editMode
• 用戶點擊一個單元格，然后所選單元格進入它自己的editMode（不是VC editMode）
• 用戶出於某種原因輕敲另一個單元格並得到提醒，一次只能編輯一個單元格
• 用戶按下“確定”並決定通過按下單元格A內的按鈕子視圖來刪除第一個選定的單元格。
• 因為用戶在單元格A上點擊“刪除”之前輕按了單元格B，所以indexPathsForSelectedItems設置為單元格B而不是單元格A，從而導致用戶不幸地刪除了錯誤的單元格。

刪除碼：

- (void)deleteProjects:(NSNotification *)notification {
// Get the current project
NSString *currentProject = [[MyManager sharedManager] projectForDeletion];

[_objects removeObject:currentProject];

[_projectsCollectionView performBatchUpdates:^{

    NSArray *selectedItemsIndexPaths = [_projectsCollectionView indexPathsForSelectedItems];

    // Now delete the items from the collection view.
    [_projectsCollectionView deleteItemsAtIndexPaths:selectedItemsIndexPaths];

} completion:nil];

// Set deleteAlert to NO as we're pretty much done with deleting
deleteAlert = NO;

// Set editedProjects to 0
editedProjects = 0;

// Set deletedProject
deletedProject = currentProject;

// Save the new objects
[[NSUserDefaults standardUserDefaults] setObject:_objects forKey:@"myProjects"];

// Delete the associated subjects if any
[self deleteAssociatedSubjects];

// HERE
[_projectsCollectionView.collectionViewLayout invalidateLayout];
}

選擇代碼：

- (void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:     (NSIndexPath *)indexPath
{
// Get the tapped cell
ProjectCell *projectCell = (ProjectCell *)[collectionView cellForItemAtIndexPath:indexPath];

if (editMode == YES) {
    if (editedProjects == 0) {
        // Set deleteAlert to YES so that we don't mix this UIAlertView
        // with the create project UIAlertView
        deleteAlert = YES;

        // Set editMode to YES for the selected cell
        [projectCell editProject];

        // Prepare the project cell
        projectCell.projectTextField.text = projectCell.projectLabel.text;

        // Set the firstProjectsViewController to YES
        // indicating that the next tapped cell will be second in line
        // in case the user decides to edit a new cell without closing this

        // Set editedProjects to 1
        editedProjects = 1;
    } else if (editedProjects == 1) {
        // Check if the tapped cell is being edited
        if (projectCell.editMode == YES) {
            // Set deleteAlert to YES so that we don't mix this UIAlertView
            // with the create project UIAlertView
            deleteAlert = YES;

            // Set editMode to YES for the selected cell
            [projectCell editProject];

            // Set editedProjects to 0
            editedProjects = 0;

            // Close the keyboard
            [self.view endEditing:YES];

            // Set editedProjects to 0 as we're closing editMode on this cell
            editedProjects = 0;

        } else if (projectCell.editMode == NO) {
            // Tell the user that only 1 project is editable at a time
            UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Can only edit 1" message:@"You can only edit 1 project at a time" delegate:nil cancelButtonTitle:@"Ok" otherButtonTitles:nil, nil];
            alert.alertViewStyle = UIAlertViewStyleDefault;
            [alert show];
        }
    }
} else {
    // Set the open project
    MyManager *sharedManager = [MyManager sharedManager];
    sharedManager.openProject = nil;
    sharedManager.openProject = @"";
    sharedManager.openProject = _objects[indexPath.item];

    // Open the selected project and dismiss this ViewController
    [self dismissViewControllerAnimated:YES completion:nil];
}
}

按鈕IBAction（單元格代碼）：

- (IBAction)deleteProjectAction:(id)sender {

// Set the projectForDeletion in MyManager
MyManager *sharedManager = [MyManager sharedManager];
sharedManager.projectForDeletion = _projectLabel.text;

// Leave editMode so that we're ready for a new project cell if desired
[self editProject];

// Programatically select this cell
self.selected = YES;

// Tell the ProjectsViewController to delete the project
[[NSNotificationCenter defaultCenter] postNotificationName:@"deleteProject" object:self];
}

簡而言之：如何輕松刪除自定義UICollectionViewCell？

我無法形容我的幸福和感激之情！

謝謝！

Answer 1

使用collectionView:shouldDeselectItemAtIndexPath:可以防止用戶取消選擇當前處於編輯模式的項目（並且通過不允許多次選擇，不應選擇被點擊的項目，盡管您也可以使用collectionView:shouldSelectItemAtIndexPath: 。

Answer 2

我通過在需要時備份NSIndexPath並將其刪除來修復它。 像這樣：

didSelectItemAtIndexPath：

    // Set the cellForDeletionIndexPath so that it won't change even though another cell is tapped
    cellForDeletionIndexPath = indexPath;

從單元格類發送的通知所調用的刪除代碼（按鈕）

    [_projectsCollectionView performBatchUpdates:^{

    // Now delete the items from the collection view.
    [_projectsCollectionView deleteItemsAtIndexPaths:[NSArray arrayWithObject:cellForDeletionIndexPath]];

} completion:nil];