ios - 在 iOS 中使用评级星 (DLStarRating) 时在滚动时卡住 UITableView

Question

我正在使用 DLStarRating用于显示评级。它工作完美，但是当我在 tableview 单元格中使用它时，滚动时卡住问题开始。我想在 UITableview 中显示评级星星分数例如:- 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

你这样做是不对的。

您应该按照以下步骤操作。

首先，您需要为标识符获取可重复使用的单元格。

如果没有可重用的单元格可用，则在其中创建并添加所需的组件/ subview 。

根据您的逻辑更改单元格及其组件/ subview 的属性和行为。

您不需要像为 DLStarRatingControl 所做的那样每次都创建 subview 。这会影响 tableview 的性能并且会卡住。

通过执行这些步骤，我将更改您的实现，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;
}

注意没有用户[UITableView registerNib: forCellReuseIdentifier:]因为您需要将评级控件添加为 subview 。您每次都添加它cellForRowAtIndexPath方法调用，现在它只会在创建新单元格时添加。

我还怀疑表格 View 卡住，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 仍然卡住，您需要为该图像实现延迟加载。