在iOS中使用评级星（DLStarRating）时，在滚动时冻结UITableView

Question

我正在使用DLStarRating来显示评分。它工作正常但是当我在tableview单元格中使用它时，冷却问题会在滚动时开始。我想在UITableview中显示评分星数 Ex： - 3.2,1.9,2,4.6等评级。

UITableViewCell *cell=nil;
if(cell==nil)
{

[tableView registerNib:[UINib nibWithNibName:@"TableViewCell" bundle:nil] forCellReuseIdentifier:@"CellID"];
cell = [tableView dequeueReusableCellWithIdentifier:@"CellID"];
cell.selectionStyle = UITableViewCellEditingStyleNone;
}
   UILabel *LabelTitle= (UILabel*)[cell viewWithTag:1];
LabelTitle.text=[[ArrayData objectAtIndex:indexPath.row] objectForKey:@"name"];


UILabel *LabelAddress= (UILabel*)[cell viewWithTag:100];
LabelAddress.text=[[ArrayData objectAtIndex:indexPath.row] objectForKey:@"address"];

UIImageView *imgView = (UIImageView*)[cell viewWithTag:200];
[imgView setImageWithURL:[NSURL URLWithString:[[ArrayData objectAtIndex:indexPath.row] objectForKey:@"icon"]] placeholderImage:[UIImage imageNamed:@"loading.png"]];

DLStarRatingControl *customNumberOfStars = [[DLStarRatingControl alloc] initWithFrame:CGRectMake(20, 140, 140, 30) andStars:5 isFractional:YES];
customNumberOfStars.delegate = self;
customNumberOfStars.backgroundColor = [UIColor groupTableViewBackgroundColor];
customNumberOfStars.autoresizingMask =  UIViewAutoresizingFlexibleLeftMargin | UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight | UIViewAutoresizingFlexibleRightMargin | UIViewAutoresizingFlexibleTopMargin | UIViewAutoresizingFlexibleBottomMargin;
customNumberOfStars.rating = [[ArrayData objectAtIndex:indexPath.row] floatValue];
[cell addSubview:customNumberOfStars];
    return cell;

Answer 1

你做错了。

您应该按照以下步骤操作。

1. 首先，您需要获取可重复使用的标识符单元格。
2. 如果没有可重复使用的单元格，则在其中创建并添加所需的组件/子视图。
3. 根据您的逻辑更改单元格及其组件/子视图的属性和行为。

您不需要每次都像创建DLStarRatingControl那样创建子视图。这会影响tableview性能并且会冻结。

按照以下步骤操作，我将更改您的实施，如下所示

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

    static NSString * CellIdentifier = @"CellID";
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
    if(cell==nil)
    {
        cell = [[NSBundle mainBundle] loadNibNamed:@"TableViewCell" owner:nil options:nil][0];
        cell.selectionStyle = UITableViewCellEditingStyleNone;

        DLStarRatingControl *customNumberOfStars = [[DLStarRatingControl alloc] initWithFrame:CGRectMake(20, 140, 140, 30) andStars:5 isFractional:YES];
        customNumberOfStars.tag = 1001;
        customNumberOfStars.delegate = self;
        customNumberOfStars.backgroundColor = [UIColor groupTableViewBackgroundColor];
        customNumberOfStars.autoresizingMask =  UIViewAutoresizingFlexibleLeftMargin | UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight | UIViewAutoresizingFlexibleRightMargin | UIViewAutoresizingFlexibleTopMargin | UIViewAutoresizingFlexibleBottomMargin;
        [cell addSubview:customNumberOfStars];
    }
    UILabel *LabelTitle= (UILabel*)[cell viewWithTag:1];
    LabelTitle.text=[[ArrayData objectAtIndex:indexPath.row] objectForKey:@"name"];


    UILabel *LabelAddress= (UILabel*)[cell viewWithTag:100];
    LabelAddress.text=[[ArrayData objectAtIndex:indexPath.row] objectForKey:@"address"];

    UIImageView *imgView = (UIImageView*)[cell viewWithTag:200];
    [imgView setImageWithURL:[NSURL URLWithString:[[ArrayData objectAtIndex:indexPath.row] objectForKey:@"icon"]] placeholderImage:[UIImage imageNamed:@"loading.png"]];

    DLStarRatingControl *customNumberOfStars = (customNumberOfStars *)[cell viewWithTag:1001];
    customNumberOfStars.rating = [[ArrayData objectAtIndex:indexPath.row] floatValue];

    return cell;
}

请注意，没有用户[UITableView registerNib: forCellReuseIdentifier:]，因为您需要将评级控件添加为子视图。您每次调用cellForRowAtIndexPath方法时都会添加它，现在只有在创建新单元格时才会添加它。

我还怀疑表视图是否冻结，因为您正在从某个URL加载图像。我不确定该图像的大小，但如果tableView仍然冻结，则需要为该图像实现延迟加载。