如何在Objective-C中的UICollectionView的didSelectItemAtIndexPath委托上顯示UIProgressView？

Question

我想在用戶單擊單元格時在集合視圖中顯示進度視圖 ，並且還想顯示該單元格進度視圖的進度。

// ...在.h文件中，我聲明了UIProgressView-

@property(nonatomic,retain)IBOutlet UIProgressView *pv;

// ...然后在.m文件中將其用作-

我在UICollectionView的方法cellForItemAtIndexPath中添加了UIProgressView ，如下所示；

- (UICollectionViewCell *)collectionView:(UICollectionView *)cv cellForItemAtIndexPath:(NSIndexPath *)indexPath
{
    UICollectionViewCell *cell = [cv dequeueReusableCellWithReuseIdentifier:@"ArticleCell" forIndexPath:indexPath];

    pv = [[UIProgressView alloc]init];
    pv.frame = CGRectMake(45, 270, 230, 50);
    pv.progress = 0.0f;
    pv.progressViewStyle = UIProgressViewStyleDefault;
    pv.hidden = YES;

   [cell.contentView addSubview:pv];

  return cell;

}

然后在didSelectItemAtIndexPath中顯示進度視圖及其進度，如下所示；

- (void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath
{
 //to show progressview in cell..
            UICollectionViewCell *selectedCell = [collView cellForItemAtIndexPath:indexPath];

            NSLog(@"subviews - %@",selectedCell.contentView.subviews);
            pv = (UIProgressView *)[selectedCell.contentView.subviews objectAtIndex:0];
            pv.hidden = NO;

           [self performSelector:@selector(checkDownload) withObject:nil afterDelay:1.0];
}


//to check whether all images are downloaded or not and showing progress accordingly
-(void)checkDownload
{
    NSError *error;

    NSArray* arrArticleImages = [[NSArray alloc]init];

    arrArticleImages = [[NSFileManager defaultManager] contentsOfDirectoryAtPath:imgPath error:&error];
    NSLog(@"arr cnt-%d",arrArticleImages.count );

    if (arrArticleImages.count <= 8)
    {
        float m = (float)arrArticleImages.count / 100;
        float t = pv.progress ;
        float g = m + t;

        pv.progress = g;

        NSLog(@"prgs-%f",g);

        [self performSelector:@selector(checkDownload) withObject:nil afterDelay:4.0];
    }
    else
    {
        pv.progress = 1.0;

        [self insertIntoDatabase];

        [self performSelector:@selector(goToNewsPaperView) withObject:nil afterDelay:2.0];
    }

    arrArticleImages = nil;
}

但是現在的問題是，我單擊一個單元格開始顯示帶有進度的進度視圖，但是一旦單擊之間的另一個單元格，第一個單元格的進度就會停止顯示進度，而第二個進度會開始顯示進度。

我想顯示每個單元格的progressview的進度（如果單擊）。

我認為我的方法是錯誤的。

我無法找到答案。

我怎樣才能做到這一點？？

請幫我。

謝謝..

Answer 1

這是因為您在didSelectItemAtIndexPath上獲得了進度視圖的新引用 。 以前對progrress視圖的看法怎么樣？

您可以在NSDictionary中使用鍵值索引路徑添加所有進度視圖 。 然后在checkDownload中傳遞您的索引路徑，然后從NSDictionary獲取具有傳遞的索引路徑的進度視圖並使用它

//在其他地方初始化NSMutable字典，然后在其中添加進度視圖

- (UICollectionViewCell *)collectionView:(UICollectionView *)cv cellForItemAtIndexPath:(NSIndexPath *)indexPath
        {
            UICollectionViewCell *cell = [cv dequeueReusableCellWithReuseIdentifier:@"ArticleCell" forIndexPath:indexPath];

            pv = [[UIProgressView alloc]init];

            [dictionary setObject:pv forKey:indexpath];

        }

或者您可以在其中添加進度視圖

- (void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath
        {
         //to show progressview in cell..
             UICollectionViewCell *selectedCell = [collView cellForItemAtIndexPath:indexPath];

             NSLog(@"subviews - %@",selectedCell.contentView.subviews);
             pv = (UIProgressView *)[selectedCell.contentView.subviews objectAtIndex:0];
             pv.hidden = NO;
             [dictionary setObject:pv forKey:indexpath];

             [self performSelector:@selector(checkDownload) withObject:indexpath afterDelay:1.0];
        }

自定義您的支票

  -(void)checkDownload:(NSIndexPath*)indexpath
    {
       pv = [dictionary objectForKey:indexpath];
    }

Answer 2

這是因為您在所有單元格中都使用相同的對象pv ，因此需要執行以下操作：

為每個單元格創建UIProgressView：

- (UICollectionViewCell *)collectionView:(UICollectionView *)cv cellForItemAtIndexPath:(NSIndexPath *)indexPath
{
    UICollectionViewCell *cell = [cv dequeueReusableCellWithReuseIdentifier:@"ArticleCell" forIndexPath:indexPath];

    UIProgressView *pv = [[UIProgressView alloc] init];
    pv.tag = 10;
    .....
}

並在didSelectItemAtIndexPath中獲取引用並將其傳遞給下載功能：

- (void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath
{
 //to show progressview in cell..
        UICollectionViewCell *selectedCell = [collView cellForItemAtIndexPath:indexPath];

        NSLog(@"subviews - %@",selectedCell.contentView.subviews);
        UIProgressView *pv = (UIProgressView *)[selectedCell viewForTag:10]; 

       // pass the progressView to your checkDownload
       [self performSelector:@selector(checkDownload:) withObject:pv afterDelay:1.0];
}

並且checkDownload將是：

-(void)checkDownload:(UIProgressView *)progressView{
   //use progressView instead of pv
   ....
}