在iPhone中重复和重叠UITableView单元格

Question

UITableView单元格在滚动时重复并且彼此重叠。 我该如何解决这个问题

这是我的代码

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    return 11;
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    UIButton *buyBtn = [UIButton buttonWithType:UIButtonTypeCustom];
    UIImageView *img;
    UILabel *lbl;
    UIImageView *backImage;
    UILabel *textLabel;
    UILabel *detailTextLabel;

    NSInteger val = [indexPath row] * 3;

    if (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad)
    {
        backImage =  [[UIImageView alloc] initWithFrame:CGRectMake(2, 4, 316, 62)];
        [buyBtn setFrame:CGRectMake(257, 35, 57, 24)];
        img = [[UIImageView alloc] initWithFrame:CGRectMake(257, 10, 57, 24)];

        lbl = [[UILabel alloc] initWithFrame:CGRectMake(0, 0, 57, 24)];
        textLabel = [[UILabel alloc] initWithFrame:CGRectMake(4, 4, 230, 25)];
        detailTextLabel = [[UILabel alloc] initWithFrame:CGRectMake(4, 25, 230, 30)];

        backImage.image = [UIImage imageNamed:@"shop-bg.png"];
        [buyBtn setImage:[UIImage imageNamed:@"buy_button"] forState:UIControlStateNormal];
        [img setImage:[UIImage imageNamed:@"price_button.png"]];
    }
    else
    {
        backImage =  [[UIImageView alloc] initWithFrame:CGRectMake(2, 4, 316, 62)];
        [buyBtn setFrame:CGRectMake(257, 35, 57, 24)];
        img = [[UIImageView alloc] initWithFrame:CGRectMake(257, 10, 57, 24)];

        lbl = [[UILabel alloc] initWithFrame:CGRectMake(0, 0, 57, 24)];
        textLabel = [[UILabel alloc] initWithFrame:CGRectMake(4, 4, 230, 25)];
        detailTextLabel = [[UILabel alloc] initWithFrame:CGRectMake(4, 25, 230, 30)];

        backImage.image = [UIImage imageNamed:@"shop-bg.png"];
        [buyBtn setImage:[UIImage imageNamed:@"buy_button"] forState:UIControlStateNormal];
        [img setImage:[UIImage imageNamed:@"price_button.png"]];
    }



    lbl.center = img.center;
    lbl.textAlignment =  UITextAlignmentCenter;
    lbl.text = [self.original_List objectAtIndex:val+2];
    lbl.backgroundColor = [UIColor clearColor];

    textLabel.font = [UIFont fontWithName:@"Arial Rounded MT Bold" size:14];
    textLabel.backgroundColor = [UIColor clearColor];
    textLabel.text = [self.original_List objectAtIndex:val];

    detailTextLabel.text = [self.original_List objectAtIndex:val+1];
    detailTextLabel.backgroundColor = [UIColor clearColor];
    detailTextLabel.font = [UIFont fontWithName:@"Arial Rounded MT Bold" size:10];
    textLabel.textColor = [UIColor blackColor];
    detailTextLabel.textColor = [UIColor whiteColor];
    detailTextLabel.numberOfLines = 2;

    [buyBtn setTag:[indexPath row]];
    [buyBtn addTarget:self action:@selector(buyBtnPressed:) forControlEvents:UIControlEventTouchDown];



    static NSString *myIdentifier = @"myIdentifier";
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:myIdentifier];
    NSLog(@"%d" , [[cell subviews] count]);
    if (cell == nil)
    {
        cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:myIdentifier];
    }
             cell.accessoryType = UITableViewCellAccessoryNone;
        [cell setSelectionStyle:UITableViewCellEditingStyleNone];
        cell.backgroundColor = [UIColor clearColor];

    [cell.contentView addSubview:backImage];
    [cell.contentView addSubview:detailTextLabel];
    [cell.contentView addSubview:textLabel];
    [cell.contentView addSubview:buyBtn];
    [cell.contentView addSubview:img];
    [cell.contentView addSubview:lbl];
    return cell;
}

Answer 1

试试这个代码：-

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    UIButton *buyBtn = [UIButton buttonWithType:UIButtonTypeCustom];
    UIImageView *img;
    UILabel *lbl;
    UIImageView *backImage;
    UILabel *textLabel;
    UILabel *detailTextLabel;

    NSInteger val = [indexPath row] * 3;

    if (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad)
    {
        backImage =  [[UIImageView alloc] initWithFrame:CGRectMake(2, 4, 316, 62)];
        [buyBtn setFrame:CGRectMake(257, 35, 57, 24)];
        img = [[UIImageView alloc] initWithFrame:CGRectMake(257, 10, 57, 24)];

        lbl = [[UILabel alloc] initWithFrame:CGRectMake(0, 0, 57, 24)];
        textLabel = [[UILabel alloc] initWithFrame:CGRectMake(4, 4, 230, 25)];
        detailTextLabel = [[UILabel alloc] initWithFrame:CGRectMake(4, 25, 230, 30)];

        backImage.image = [UIImage imageNamed:@"shop-bg.png"];
        [buyBtn setImage:[UIImage imageNamed:@"buy_button"] forState:UIControlStateNormal];
        [img setImage:[UIImage imageNamed:@"price_button.png"]];
    }
    else
    {
        backImage =  [[UIImageView alloc] initWithFrame:CGRectMake(2, 4, 316, 62)];
        [buyBtn setFrame:CGRectMake(257, 35, 57, 24)];
        img = [[UIImageView alloc] initWithFrame:CGRectMake(257, 10, 57, 24)];

        lbl = [[UILabel alloc] initWithFrame:CGRectMake(0, 0, 57, 24)];
        textLabel = [[UILabel alloc] initWithFrame:CGRectMake(4, 4, 230, 25)];
        detailTextLabel = [[UILabel alloc] initWithFrame:CGRectMake(4, 25, 230, 30)];

        backImage.image = [UIImage imageNamed:@"shop-bg.png"];
        [buyBtn setImage:[UIImage imageNamed:@"buy_button"] forState:UIControlStateNormal];
        [img setImage:[UIImage imageNamed:@"price_button.png"]];
    }



    lbl.center = img.center;
    lbl.textAlignment =  UITextAlignmentCenter;
    lbl.text = [self.original_List objectAtIndex:val+2];
    lbl.backgroundColor = [UIColor clearColor];

    textLabel.font = [UIFont fontWithName:@"Arial Rounded MT Bold" size:14];
    textLabel.backgroundColor = [UIColor clearColor];
    textLabel.text = [self.original_List objectAtIndex:val];

    detailTextLabel.text = [self.original_List objectAtIndex:val+1];
    detailTextLabel.backgroundColor = [UIColor clearColor];
    detailTextLabel.font = [UIFont fontWithName:@"Arial Rounded MT Bold" size:10];
    textLabel.textColor = [UIColor blackColor];
    detailTextLabel.textColor = [UIColor whiteColor];
    detailTextLabel.numberOfLines = 2;

    [buyBtn setTag:[indexPath row]];
    [buyBtn addTarget:self action:@selector(buyBtnPressed:) forControlEvents:UIControlEventTouchDown];



    static NSString *myIdentifier = @"myIdentifier";
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:myIdentifier];
    NSLog(@"%d" , [[cell subviews] count]);
    //if (cell == nil)
    {
        cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:myIdentifier];
    }
             cell.accessoryType = UITableViewCellAccessoryNone;
        [cell setSelectionStyle:UITableViewCellEditingStyleNone];
        cell.backgroundColor = [UIColor clearColor];

    [cell.contentView addSubview:backImage];
    [cell.contentView addSubview:detailTextLabel];
    [cell.contentView addSubview:textLabel];
    [cell.contentView addSubview:buyBtn];
    [cell.contentView addSubview:img];
    [cell.contentView addSubview:lbl];
    return cell;
}

Answer 2

您需要在- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath;检查单元格的高度- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath;

它应该更大，然后代码中使用的最大高度可能是65

Answer 3

不要使用复用标识符并将其设置为nil。

UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:nil];
    if (cell == nil)
    {
        cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:nil];


    }

Answer 4

这里发生的是您使用

UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:myIdentifier];

此代码可确保在UITableView中滚动时，单元被重用以节省内存。 由于您对所有单元格都使用相同的标识符，因此它将仅重用已经具有“ backImage”，“ detailTextLabel”等元素的单元格，并将新视图组件添加到现有组件的顶部。

您可以使用类似于以下的代码来解决此问题：

static NSString *myIdentifier = @"myIdentifier";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:myIdentifier];
if (cell == nil)
{
    cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:myIdentifier];
    // Create backImage, detailTextLabel, etc. here
    ...

    // Give view components tags
    backImage.tag = 1;
    detailTextLabel.tag = 2;
    ...
}

UIImageView* retrievedBackImage = (UIImageView*)[cell.contentView viewWithTag:1];
UILabel* retrievedDetailTextLabel = (UILabel *)[cell.contentView viewWithTag:2];
...
// Initialise values
retrievedBackImage.image = [UIImage imageNamed:@"someImage.png"];
retrievedDetailTextLabel.text = @"something";
...

希望这会有所帮助。

尼古拉斯