Question

我有一个包含25个单元格的集合视图对于一个单元格，我创建了文本颜色为白色。现在当我重新加载集合视图时，其他单元格文本颜色也会在我重新加载集合视图时逐个变为白色。我不知道问题出在哪里。这是我的代码。

        if (indexPath.item == 0)
    {
        myCell.hidden=NO;
        NSLog(@"index path = %ld",(long)indexPath.row );
        NSArray *Object=  [[jsonData valueForKey:@"TimeTabledPeriods"]objectAtIndex:0];
        NSLog(@"object %@",Object);
        myCell.roomLabel.text= [NSString stringWithFormat:@"Room: %@", [Object valueForKey:@"RoomDescription"]];
        myCell.subjectLabel.text =  [Object valueForKey:@"SubjectDescription"];
        [myCell.redXbuttonOutlet setTag:indexPath.row];
        [myCell.redXbuttonOutlet addTarget:self action:@selector(buttonPressed:) forControlEvents:UIControlEventTouchUpInside];
        myCell.noSessionView.backgroundColor=[UIColor clearColor];
        myCell.myLearningChoicesBackground.hidden=YES;

        if ([[Object valueForKey:@"Changed"] isEqualToString:@"YES"])
        {
            if ([[Object valueForKey:@"ChangedColorCode"] isEqualToString:@"Present"])
            {
                myCell.noSessionView.backgroundColor=[UIColor colorWithRed:97.0/255.0 green:182.0/255.0 blue:73/255.0 alpha:1];

    //The below lines to change the text color to white is written only for index path  0
                myCell.roomLabel.textColor=[UIColor whiteColor];
                myCell.subjectLabel.textColor=[UIColor whiteColor];

            }

        }
//code for other cells

    if (indexPath.item == 1)
{
    myCell.hidden=NO;
    NSLog(@"index path = %ld",(long)indexPath.row );
    NSArray *Object=  [[jsonData valueForKey:@"TimeTabledPeriods"]objectAtIndex:0];
    NSLog(@"object %@",Object);
    myCell.roomLabel.text= [NSString stringWithFormat:@"Room: %@", [Object valueForKey:@"RoomDescription"]];
    myCell.subjectLabel.text =  [Object valueForKey:@"SubjectDescription"];
    [myCell.redXbuttonOutlet setTag:indexPath.row];
    [myCell.redXbuttonOutlet addTarget:self action:@selector(buttonPressed:) forControlEvents:UIControlEventTouchUpInside];
    myCell.noSessionView.backgroundColor=[UIColor clearColor];
    myCell.myLearningChoicesBackground.hidden=YES;

    if ([[Object valueForKey:@"Changed"] isEqualToString:@"YES"])
    {
        if ([[Object valueForKey:@"ChangedColorCode"] isEqualToString:@"Present"])
        {
            myCell.noSessionView.backgroundColor=[UIColor colorWithRed:97.0/255.0 green:182.0/255.0 blue:73/255.0 alpha:1];

        }

    }

    if (indexPath.item == 3)
{
    myCell.hidden=NO;
    NSLog(@"index path = %ld",(long)indexPath.row );
    NSArray *Object=  [[jsonData valueForKey:@"TimeTabledPeriods"]objectAtIndex:0];
    NSLog(@"object %@",Object);
    myCell.roomLabel.text= [NSString stringWithFormat:@"Room: %@", [Object valueForKey:@"RoomDescription"]];
    myCell.subjectLabel.text =  [Object valueForKey:@"SubjectDescription"];
    [myCell.redXbuttonOutlet setTag:indexPath.row];
    [myCell.redXbuttonOutlet addTarget:self action:@selector(buttonPressed:) forControlEvents:UIControlEventTouchUpInside];
    myCell.noSessionView.backgroundColor=[UIColor clearColor];
    myCell.myLearningChoicesBackground.hidden=YES;

    if ([[Object valueForKey:@"Changed"] isEqualToString:@"YES"])
    {
        if ([[Object valueForKey:@"ChangedColorCode"] isEqualToString:@"Present"])
        {
            myCell.noSessionView.backgroundColor=[UIColor colorWithRed:97.0/255.0 green:182.0/255.0 blue:73/255.0 alpha:1];

        }

    }

//等等 }

Answer 1

我认为你想要的是第一项，而不是第一项。

if (indexPath.item == 0)
{
    myCell.hidden=NO;
    NSLog(@"index path = %ld",(long)indexPath.row );
    NSArray *Object=  [[jsonData valueForKey:@"TimeTabledPeriods"]objectAtIndex:0];
    NSLog(@"object %@",Object);
    myCell.roomLabel.text= [NSString stringWithFormat:@"Room: %@", [Object valueForKey:@"RoomDescription"]];
    myCell.subjectLabel.text =  [Object valueForKey:@"SubjectDescription"];
    [myCell.redXbuttonOutlet setTag:indexPath.row];
    [myCell.redXbuttonOutlet addTarget:self action:@selector(buttonPressed:) forControlEvents:UIControlEventTouchUpInside];
    myCell.noSessionView.backgroundColor=[UIColor clearColor];
    myCell.myLearningChoicesBackground.hidden=YES;

    if ([[Object valueForKey:@"Changed"] isEqualToString:@"YES"])
    {
        if ([[Object valueForKey:@"ChangedColorCode"] isEqualToString:@"Present"])
        {
            myCell.noSessionView.backgroundColor=[UIColor colorWithRed:97.0/255.0 green:182.0/255.0 blue:73/255.0 alpha:1];

//The below lines to change the text color to white is written only for index path  0
            myCell.roomLabel.textColor=[UIColor whiteColor];
            myCell.subjectLabel.textColor=[UIColor whiteColor];

        }

    }

修改

这是我处理集合视图单元格的方式。

UICollectionViewCell *cell = [self.collectionView cellForItemAtIndexPath:indexPath]; //cell.backgroundColor = [UIColor greenColor]; UILabel *label = (UILabel *)[cell viewWithTag:101]; UIImageView *recipeImageView = (UIImageView *)[cell viewWithTag:100]; UIStoryboard *storyboard=[[UIStoryboard alloc] init]; currentIndexPath=indexPath; int selectedCellNum=(int)indexPath.item; if (selectedCellNum==0) { if (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPhone) { storyboard = [UIStoryboard storyboardWithName:@"Main_iPhone" bundle:nil]; } else { storyboard = [UIStoryboard storyboardWithName:@"Main_iPad" bundle:nil]; } recipeImageView.image = [UIImage imageNamed:@"1B copy.png"]; label.textColor = [UIColor blackColor]; POISTableViewController * destViewController = [storyboard instantiateViewControllerWithIdentifier:@"POISList"]; destViewController.selectedCategory=0; destViewController.sightsToShow=self.groups; [self.navigationController pushViewController:destViewController animated:YES]; } else if (selectedCellNum==1) { if (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPhone) { storyboard = [UIStoryboard storyboardWithName:@"Main_iPhone" bundle:nil]; } else { storyboard = [UIStoryboard storyboardWithName:@"Main_iPad" bundle:nil]; } recipeImageView.image = [UIImage imageNamed:@"2B copy.png"]; label.textColor = [UIColor blackColor]; MonumentsViewController * destViewController = [storyboard instantiateViewControllerWithIdentifier:@"MonumentsViewController"]; destViewController.sightsToShow=self.groups; [self.navigationController pushViewController:destViewController animated:YES]; }

Answer 2

这种行为没有“奇怪”，这是因为没有妥善处理细胞再利用。您在第一个if子句中将文本设置为白色，但从未将其设置回其他if子句中的任何其他颜色。因此，当重复使用该单元格时，它的文本仍将设置为白色。除了颜色变化之外，代码似乎在每个if子句中都是相同的，所以你甚至不应该拥有每个项目的所有if子句;您需要重构代码以消除所有重复。在任何if子句之外，如果你实际上仍然需要其中任何一个，你应该将文本颜色设置为白色仅用于项目0，而将黑色设置为所有其他项目，

myCell.roomLabel.textColor = (indexPath.item == 0)? [UIColor whiteColor] : [UIColor blackColor];
myCell.subjectLabel.textColor= (indexPath.item == 0)? [UIColor whiteColor] : [UIColor blackColor];

Collection视图中的奇怪行为

2 个答案: