我有一个显示数据的UITableView，但是当它滚动时，数据（UILabel）会消失，或者它们会一遍又一遍地叠加在一起。每次我滚动每个细胞交换数据。
这是我的cellForRowAtIndexPath:代码
-(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *cellIdentifier = @"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:cellIdentifier];
if(cell == nil) {
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:cellIdentifier];
}
cell.selectionStyle = UITableViewCellSelectionStyleNone;
// configure the cell's background
UIImageView *gradient = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"gradient"]];
[cell.contentView addSubview:gradient];
// configure the cell's label
UILabel *nameLabel = [[UILabel alloc] initWithFrame:CGRectMake(50, 130, 300, 44)];
// grab a reference to the label's text from the tableData
nameLabel.text = [name objectAtIndex:indexPath.row];
nameLabel.textColor = [UIColor blackColor];
nameLabel.font = [UIFont fontWithName:@"DIN-Bold" size:12];
nameLabel.backgroundColor = [UIColor clearColor];
// set the autoReiszing mask -- this way if the label spills over the editing
// [icon?] then the text will trail off in ...
nameLabel.autoresizingMask = UIViewAutoresizingFlexibleWidth;
[cell.contentView addSubview:nameLabel];
// configure the cell's label
UILabel *tableTextViewLbl = [[UILabel alloc] initWithFrame:CGRectMake(50, 80, 220, 50)];
// grab a reference to the label's text from the tableData
tableTextViewLbl.text = [message objectAtIndex:indexPath.row];
tableTextViewLbl.textColor = [UIColor blackColor];
tableTextViewLbl.font = [UIFont fontWithName:@"DIN" size:10];
tableTextViewLbl.backgroundColor = [UIColor clearColor];
tableTextViewLbl.autoresizingMask = UIViewAutoresizingFlexibleWidth;
[cell.contentView addSubview:tableTextViewLbl];
// configure the cell's label
UILabel *tableTimeStampViewLbl = [[UILabel alloc] initWithFrame:CGRectMake(50, 30, 200, 50)];
// grab a reference to the label's text from the tableData
tableTimeStampViewLbl.text = [timeStamp objectAtIndex:indexPath.row];
tableTimeStampViewLbl.textColor = [UIColor lightGrayColor];
tableTimeStampViewLbl.font = [UIFont fontWithName:@"DIN" size:7];
tableTimeStampViewLbl.backgroundColor = [UIColor clearColor];
tableTimeStampViewLbl.autoresizingMask = UIViewAutoresizingFlexibleWidth;
[cell.contentView addSubview:tableTimeStampViewLbl];
// UIImageView *image;
// UIImage *image1=[UIImage imageNamed:@"rest.png"];
// image=[[UIImageView alloc]initWithImage:image1];
// image.frame=CGRectMake(10,30,40,30);
//
// [cell.contentView addSubview:image];
//
return cell;
}
答案 0 :(得分：3)
每次将单元格加载/重新加载到视图中时，您都在创建UILabel实例。这不是它的完成方式。相反 - 在UITableView子类中添加UILabel作为属性（可能是IBOutlet）并在cellForRowAtIndexPath:中更改它。
所以你会有一个新类，继承自UITableViewCell - 让我们称之为MyCustomCell。
在MyCustomCell.h中：
@interface MyCustomCell : UITableViewCell
@property (weak, nonatomic) IBOutlet UILabel *nameLabel;
@end
MyCustomCell.xib将定义UILabel位置和配置，当然需要与nameLabel属性相关联。
在cellForRowAtIndexPath中，您只需引用cell.nameLabel并更改文本，而不是实例化新的UILabel。确保在接口构建器中为单元类定义resuseIdentifier，并使用以下方法对其进行实例化：
MyCustomCell *cell = [tableView dequeueReusableCellWithIdentifier:@"MyIdentifier"];
if (!cell) {
cell = [[MyCustomCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:@"MyIdentifier"];
}
答案 1 :(得分：1)
只需添加以下代码
即可NSArray *subviews = [[NSArray alloc] initWithArray:cell.contentView.subviews];
for (UILabel *subview in subviews)
{
[subview removeFromSuperview];
}
[subviews release];
subviews = nil;
之后 -
if (cell == nil)
{
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];
}
然后添加您的代码。
答案 2 :(得分：0)
在您按照我的回答之前，我想告诉您，以下代码对内存管理不利，因为它会为UITableView的每一行创建新单元格，所以要小心。
但最好使用，当UITableView有限行（约50-100可能）时，以下代码对您的情况有帮助，如果它适合于它，请使用它你。
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
NSString *CellIdentifier = [NSString stringWithFormat:@"S%1dR%1d",indexPath.section,indexPath.row];
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if(cell == nil)
{
cell = [[[UITableViewCell alloc]initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
/// Put your code here
}
return cell;
}
如果您的行数有限，那么这是最好的代码。
答案 3 :(得分：0)
首先，您需要了解UITableView的工作原理。实际上UItableView Cell的概念是每次滚动表格视图时，它不会为您创建新单元格，它只是在cellIdentifier的帮助下重用单元格。
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:cellIdentifier];那时我们需要更新单元格的数据。就是这样，更好。你可以在下面看到：
-(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *cellIdentifier = @"Cell";
UILabel *nameLabel = nil;
UILabel *tableTextViewLbl= nil;
UILabel *tableTimeStampViewLbl= nil;
//Here we are , reuse the cells...
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:cellIdentifier];
if(cell == nil) {
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:cellIdentifier];
cell.selectionStyle = UITableViewCellSelectionStyleNone;
// configure the cell's background
UIImageView *gradient = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"gradient"]];
[cell.contentView addSubview:gradient];
// configure the cell's label
nameLabel = [[UILabel alloc] initWithFrame:CGRectMake(50, 130, 300, 44)];
// grab a reference to the label's text from the tableData
nameLabel.textColor = [UIColor blackColor];
nameLabel.font = [UIFont fontWithName:@"DIN-Bold" size:12];
nameLabel.backgroundColor = [UIColor clearColor];
nameLabel.tag = 111;//Giving this component to tag so we can access it
// set the autoReiszing mask -- this way if the label spills over the editing
// [icon?] then the text will trail off in ...
nameLabel.autoresizingMask = UIViewAutoresizingFlexibleWidth;
[cell.contentView addSubview:nameLabel];
// configure the cell's label
tableTextViewLbl = [[UILabel alloc] initWithFrame:CGRectMake(50, 80, 220, 50)];
tableTextViewLbl.textColor = [UIColor blackColor];
tableTextViewLbl.font = [UIFont fontWithName:@"DIN" size:10];
tableTextViewLbl.backgroundColor = [UIColor clearColor];
tableTextViewLbl.autoresizingMask = UIViewAutoresizingFlexibleWidth;
tableTextViewLbl.tag = 222;//Giving this component to tag so we can access it
[cell.contentView addSubview:tableTextViewLbl];
// configure the cell's label
tableTimeStampViewLbl = [[UILabel alloc] initWithFrame:CGRectMake(50, 30, 200, 50)];
tableTimeStampViewLbl.textColor = [UIColor lightGrayColor];
tableTimeStampViewLbl.font = [UIFont fontWithName:@"DIN" size:7];
tableTimeStampViewLbl.backgroundColor = [UIColor clearColor];
tableTimeStampViewLbl.autoresizingMask = UIViewAutoresizingFlexibleWidth;
tableTimeStampViewLbl.tag = 333;//Giving this component to tag so we can access it
[cell.contentView addSubview:tableTimeStampViewLbl];
}
nameLabel = (UILabel*)[cell.contentView viewWithTag:111];//Here we access the name label with the help of tag, is that we have assigned tag while making the componant.
nameLabel.text = [name objectAtIndex:indexPath.row];
tableTextViewLbl = (UILabel*)[cell.contentView viewWithTag:222];//Here we access the name label with the help of tag, is that we have assigned tag while making the componant.
// grab a reference to the label's text from the tableData
tableTextViewLbl.text = [message objectAtIndex:indexPath.row];
tableTimeStampViewLbl = (UILabel*)[cell.contentView viewWithTag:333];//Here we access the name label with the help of tag, is that we have assigned tag while making the componant.
// grab a reference to the label's text from the tableData
tableTimeStampViewLbl.text = [timeStamp objectAtIndex:indexPath.row];
return cell;
}
答案 4 :(得分：-2)
使用这种方式
if (cell == nil) {
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];
}
else{
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];
}
但是采用自定义单元格是最好的答案。检查此链接是custom cell
的最佳解决方案