使用dequereusable單元格重疊滾動後的uitableview單元格的內容

Question

當我使用dequeReusableCell，當我向下滾動或向上滾動最後單元格（即從可見屏幕出去）的內容時會重疊，但每次創建新單元格時都會起作用。 我想使用dequereusble功能。

下面的代碼工作，但當我取消註釋dequereusable問題的部分再次出現。

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath 
{ 

static NSString *cellIdentifier=@"Cell"; 

    //Code causing problem 
    /*UITableViewCell *cell=[tableView dequeueReusableCellWithIdentifier:cellIdentifier]; 

    if(!cell) 
    { 
     cell=[[UITableViewCell alloc]initWithStyle:UITableViewCellStyleDefault reuseIdentifier:cellIdentifier]; 
    }*/ 

    //Code working fine 
    UITableViewCell *cell=[[UITableViewCell alloc]initWithStyle:UITableViewCellStyleDefault reuseIdentifier:cellIdentifier]; 

    UILabel *titleLabel=[[UILabel alloc]initWithFrame:CGRectMake(10, 10, 180, 20)]; 
    [titleLabel setFont:[UIFont boldSystemFontOfSize:15]]; 

    UIImageView *headerImageView=[[UIImageView alloc]initWithFrame:CGRectMake(0, 0, 320, 200)]; 
    headerImageView.image=[UIImage imageNamed:@"offer_details.jpg"]; 

    UILabel *detailLabel=[[UILabel alloc]initWithFrame:CGRectMake(10, 30, 300, 20)]; 
    [detailLabel setFont:[UIFont systemFontOfSize:14]]; 

    UIButton *callButton=[[UIButton alloc]initWithFrame:CGRectMake(10, 30, 20, 20)]; 
    [callButton setBackgroundColor:[UIColor orangeColor]]; 

    MKMapView *mapView=[[MKMapView alloc] initWithFrame:CGRectMake(10, 30, 320, 200)]; 

    switch (indexPath.row) { 
     case 0: 
      [cell.contentView addSubview:headerImageView]; 
      [cell setBackgroundColor:[UIColor blackColor]]; 
      titleLabel.text=@"Get great offer Upto 20% Off"; 
      titleLabel.frame=CGRectMake(10, 220, 230, 20); 
      titleLabel.textColor=[UIColor colorWithRed:251.0/255.0f green:78.0f/255.0f blue:8.0f/255.0f alpha:1]; 
      detailLabel.frame=CGRectMake(10, 240, 300, 20); 
      detailLabel.textColor=[UIColor whiteColor]; 
      detailLabel.text=@"Lorem ipsum dolor sit er elit lamet, consectetaur cillium adipisicing pecu, sed do eiusmod tempor incididunt."; 
      [cell.contentView addSubview:detailLabel]; 
      break; 
     case 1: 
      titleLabel.text=@"Details"; 
      detailLabel.text=@"Lorem ipsum dolor sit er elit lamet, consectetaur cillium adipisicing pecu, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. "; 
      [cell.contentView addSubview:detailLabel]; 
      break; 
     case 2: 
      titleLabel.text=@"Collection Methods"; 
      detailLabel.text=@"Call and Reserve"; 
      detailLabel.frame=CGRectMake(50, 30, 300, 20); 
      [cell.contentView addSubview:detailLabel]; 
      [cell.contentView addSubview:callButton]; 
      break; 
     case 3: 
      titleLabel.text=@"Location"; 
      [cell.contentView addSubview:mapView]; 
      break; 
     case 4: 
      titleLabel.text=@"About us"; 
      detailLabel.text=@"Lorem ipsum dolor sit er elit lamet, consectetaur cillium adipisicing pecu, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum. Nam liber te conscient to factor tum poen legum odioque civiuda."; 
      [cell.contentView addSubview:detailLabel]; 
      break; 
     case 5: 
      titleLabel.text=@"Legal"; 
      detailLabel.text=@"Lorem ipsum dolor sit er elit lamet, consectetaur cillium adipisicing pecu, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum. Nam liber te conscient to factor tum poen legum odioque civiuda."; 
      [cell.contentView addSubview:detailLabel]; 

      break; 
     default: 
      break; 
    } 

    detailLabel.numberOfLines=0; 
    [detailLabel sizeToFit]; 
    [cell.contentView addSubview:titleLabel]; 


    return cell; 
} 

編輯：

我將能夠使用dequereusable細胞，因爲我行的內容是不常見？一行包含圖像，一個包含mapview，一個僅包含標籤。提前Thanx。

EDIT2：

@HRM現在其示出細節拉布勒空白除第一小區

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath 

{ 靜態的NSString * cellIdentifier = @ 「小區」;

UITableViewCell *cell=[tableView dequeueReusableCellWithIdentifier:cellIdentifier]; 

//UITableViewCell *cell; 

if(!cell) 
{ 
    cell=[[UITableViewCell alloc]initWithStyle:UITableViewCellStyleDefault reuseIdentifier:cellIdentifier]; 

    UILabel *titleLabel=[[UILabel alloc]initWithFrame:CGRectMake(10, 10, 180, 20)]; 
    [titleLabel setFont:[UIFont boldSystemFontOfSize:13]]; 
    titleLabel.tag=1001; 

    [cell.contentView addSubview:titleLabel]; 
    switch (indexPath.row) { 
     case 0: 
     { 
      UIImageView *headerImageView=[[UIImageView alloc]initWithFrame:CGRectMake(0, 0, 320, 200)]; 
      headerImageView.image=[UIImage imageNamed:@"offer_details.jpg"]; 
      headerImageView.tag=1002; 

      UILabel *detailLabel=[[UILabel alloc]initWithFrame:CGRectMake(10, 30, 300, 20)]; 
      [detailLabel setFont:[UIFont systemFontOfSize:12]]; 
      detailLabel.tag=1003; 
      detailLabel.numberOfLines=0; 
      [detailLabel sizeToFit]; 
      [cell.contentView addSubview:headerImageView]; 
      [cell.contentView addSubview:detailLabel]; 
     } 
      break; 

     case 1: 
     { 
      UILabel *detailLabel=[[UILabel alloc]initWithFrame:CGRectMake(10, 30, 300, 20)]; 
      [detailLabel setFont:[UIFont systemFontOfSize:12]]; 
      detailLabel.numberOfLines=0; 
      [detailLabel sizeToFit]; 
      [cell.contentView addSubview:detailLabel]; 
      detailLabel.tag=1004; 
     } 
      break; 
     case 2: 
     { 
      UILabel *detailLabel=[[UILabel alloc]initWithFrame:CGRectMake(10, 30, 300, 20)]; 
      [detailLabel setFont:[UIFont systemFontOfSize:12]]; 
      UIButton *callButton=[[UIButton alloc]initWithFrame:CGRectMake(10, 30, 15, 15)]; 
      [callButton setBackgroundColor:[UIColor orangeColor]]; 
      detailLabel.numberOfLines=0; 
      [detailLabel sizeToFit]; 
      [cell.contentView addSubview:detailLabel]; 
      detailLabel.tag=1005; 
      [cell.contentView addSubview:callButton]; 
     } 
      break; 
     case 3: 
     { 
      MKMapView *mapView=[[MKMapView alloc] initWithFrame:CGRectMake(0, 30, 320, 140)]; 
      [cell.contentView addSubview:mapView]; 
     } 
      break; 
     case 4: 
     { 
      UILabel *detailLabel=[[UILabel alloc]initWithFrame:CGRectMake(10, 30, 300, 20)]; 
      [detailLabel setFont:[UIFont systemFontOfSize:12]]; 
      detailLabel.tag=1006; 
      detailLabel.numberOfLines=0; 
      [detailLabel sizeToFit]; 
      [cell.contentView addSubview:detailLabel]; 
     } 
      break; 
     case 5: 
     { 
      UILabel *detailLabel=[[UILabel alloc]initWithFrame:CGRectMake(10, 30, 300, 20)]; 
      [detailLabel setFont:[UIFont systemFontOfSize:12]]; 
      detailLabel.tag=1007; 
      detailLabel.numberOfLines=0; 
      [detailLabel sizeToFit]; 
      [cell.contentView addSubview:detailLabel]; 
     } 
      break; 
     default: 
      break; 
    } 
} 


switch (indexPath.row) { 
    case 0: 
    { 
     [cell setBackgroundColor:[UIColor blackColor]]; 
     UILabel *titleLabel = (UILabel*)[cell.contentView viewWithTag:1001]; 
     UILabel *detailLabel=(UILabel*)[cell.contentView viewWithTag:1003]; 
     titleLabel.text=@"Get great offer Upto 20% Off"; 
     titleLabel.frame=CGRectMake(10, 210, 230, 20); 
     titleLabel.textColor=[UIColor colorWithRed:251.0/255.0f green:78.0f/255.0f blue:8.0f/255.0f alpha:1]; 
     detailLabel.frame=CGRectMake(10, 230, 300, 20); 
     detailLabel.textColor=[UIColor whiteColor]; 
     detailLabel.text=@"Lorem ipsum dolor sit er elit lamet, consectetaur cillium adipisicing pecu, sed do eiusmod tempor incididunt."; 
    } 
     break; 
    case 1: 
    { 
     UILabel *titleLabel = (UILabel*)[cell.contentView viewWithTag:1001]; 
     UILabel *detailLabel=(UILabel*)[cell.contentView viewWithTag:1004]; 
     titleLabel.text=@"Details"; 
     detailLabel.text=@"Lorem ipsum dolor sit er elit lamet, consectetaur cillium adipisicing pecu, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. "; 
    } 
     break; 
    case 2: 
    { 
     UILabel *titleLabel = (UILabel*)[cell.contentView viewWithTag:1001]; 
     UILabel *detailLabel=(UILabel*)[cell.contentView viewWithTag:1005]; 
     titleLabel.text=@"Collection Methods"; 
     detailLabel.text=@"Call and Reserve"; 
     detailLabel.frame=CGRectMake(30, 30, 300, 20); 

    } 
     break; 
    case 3: 
    { 
     UILabel *titleLabel = (UILabel*)[cell.contentView viewWithTag:1001]; 
     titleLabel.text=@"Location"; 
    } 
     break; 
    case 4: 
    { 
     UILabel *titleLabel = (UILabel*)[cell.contentView viewWithTag:1001]; 
     UILabel *detailLabel=(UILabel*)[cell.contentView viewWithTag:1006]; 
     titleLabel.text=@"About us"; 
     detailLabel.text=@"Lorem ipsum dolor sit er elit lamet, consectetaur cillium adipisicing pecu, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. \n\n Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum. Nam liber te conscient to factor tum poen legum odioque civiuda."; 
    } 
     break; 
    case 5: 
    { 
     UILabel *titleLabel = (UILabel*)[cell.contentView viewWithTag:1001]; 
     UILabel *detailLabel=(UILabel*)[cell.contentView viewWithTag:1007]; 
     titleLabel.text=@"Legal"; 
     detailLabel.text=@"Lorem ipsum dolor sit er elit lamet, consectetaur cillium adipisicing pecu, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. \n\n Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum. Nam liber te conscient to factor tum poen legum odioque civiuda."; 

    } 
     break; 
    default: 
     break; 
} 





return cell; 

}

Answer 1

當您使用dequeueReusableCellWithIdentifier，該會的tableView重新使用現有的細胞，並在你的代碼，你想一次又一次地創造新的控件，因此它會重疊。這樣做的最好方法就是這樣。請通過這個。希望能幫助到你。

根據您的評論更新。

static NSString *cellIdentifier= @"Cell"; 
UITableViewCell *cell=[tableView dequeueReusableCellWithIdentifier:cellIdentifier]; 

//If tableView dont have cell available for reuse, then 
//create a new cell and attach the controls to it 
if(cell == nil) 
{ 
    cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:cellIdentifier]; 

    if(indexPath.row == 0){ 

     UILabel *titleLabel=[[UILabel alloc]initWithFrame:CGRectMake(10, 10, 180, 20)]; 
    [titleLabel setFont:[UIFont boldSystemFontOfSize:15]]; 
     titleLabel.tag = 1002; 
     [cell.contentView addSubview:titleLabel]; 
    } 
} 

//Now we have a cell object with controls attached. 
//Now to update the contents on the control, just get the control from cell 
//using its tag and set your data from datasource 
if(indexPath.row == 0){ 
    UILabel *titleLabel = (UILabel*)[cell.contentView viewWithTag:1002]; 
    titleLabel.text = //Text from your datasource for this row 
} 

請注意，您還需要注意heightForRowAtIndexPath中的高度。同樣的邏輯也將應用於那裏。

Answer 2

這裏就是我會建議：

1. 創建一個自定義UITableViewCell類，並在其initWithStyle:reuseIdentifier:創建所需的所有子視圖。您還需要將您的子視圖分配給外部使用的屬性。
2. 告訴您的UITableView對象在viewDidLoad中註冊該課程或NIB。
3. 在tableView:cellForRowAtIndexPath:中，您可以訪問單元格的屬性並適當更新它們。

這樣，每次調用tableView:cellForRowAtIndexPath:時都不會重新創建單元格或其子視圖。

Answer 3

我建議通過objective-C枚舉從cellForRowAtInddexPath中的UITableViewCell的內容視圖中刪除子視圖。查看以下代碼以供參考。

for(UIView *view in cell.contentView.subviews){ 
    if ([view isKindOfClass:[UIView class]]) { 
     [view removeFromSuperview]; 
    } 
}