iphone - 丑陋的heightForRowAtIndexPath和cellForRowAtIndexPath

我有一个UItableview，我使用heightForRowAtIndexPath和cellForRowAtIndexPath填充了数据。显然，Apple使我在代码中执行了两次操作。

首先，我必须用heightForRowAtIndexPath计算视图的大小(为此，我必须制作它们)，然后必须再次制作它们，以将它们添加到实际视图中。

我有一个非常复杂的视图，因此当您不得不编写两次时，它看起来很难看。

有没有更好的方法可以做到这一点？

更新

这就是我的代码的样子。它不完全相同，但是非常接近。为什么世界上苹果要我写两次这个？

- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath{
    NSLog(@"heightForRowAtIndexPath");

    //Initiating strings
    NSString *headlineString;
    NSString *subHeadlineString;
    NSString *bylineString;
    if (global.magazine.issues.count==0) {
        return 45;
    }else if(indexPath.section == global.magazine.issues.count+1) {
        //Finding the right issue and article for this row
        Issue *issue = [global.magazine.issues objectAtIndex:global.magazine.issues.count-1];

        //Creating the headline
        headlineString = [NSString stringWithFormat:@"<span class='bold_style'>FOREWORD</span>"];

        //Creating the subHeadline
        subHeadlineString = [NSString stringWithFormat:@"%@", [issue.magazine_foreword substringToIndex:100]];

        //Creating byline
        bylineString = [[NSString stringWithFormat:@"<span class='ital_style'>By %@</span>", issue.magazine_byline] capitalizedString];
    }else{
        //Finding the right issue and article for this row
        Issue *issue = [global.magazine.issues objectAtIndex:indexPath.section-1];
        Article *article = [issue.articles objectAtIndex:indexPath.row];

        //Creating the headline
        headlineString = [NSString stringWithFormat:@"<span class='bold_style'>%@</span>", [article.title uppercaseString]];

        //Creating the subHeadline
        subHeadlineString = [NSString stringWithFormat:@"%@", [article.main_text substringToIndex:100]];

        //Creating byline
        bylineString = [NSString stringWithFormat:@"<span class='ital_style'>By %@</span>", article.byline];
    }

    //Creating the labels
    NMCustomLabel *headline = [global.label headLineLabelWithString:headlineString fromTop:30 withWidth:global.screenWidth-60];
    NMCustomLabel *subHeadline = [global.label subHeadlineLabelWithString:subHeadlineString fromTop:30+headline.height+10 withWidth:global.screenWidth-60];
    NMCustomLabel *byline = [global.label articleBylineLabelWithString:bylineString fromTop:30+headline.height+10+subHeadline.height+10 withWidth:global.screenWidth-60];

    //Setting the height of the row
    return 30+headline.height+10+subHeadline.height+10+byline.height+30;
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{
    NSLog(@"cellForRowAtIndexPath");
    //Preparing the cell
    static NSString *CellIdentifier = @"Cell";
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier forIndexPath:indexPath];
    if (cell == nil) {
        cell = [[UITableViewCell alloc]
                initWithStyle:UITableViewCellStyleDefault
                reuseIdentifier:CellIdentifier];
    }

    //Removing former text views
    for (UIView *subview in [cell subviews]) {
        if (subview.tag == 21 || subview.tag == 22 || subview.tag == 23) [subview removeFromSuperview];
    }

    //Removing and setting tableview border
    [[cell viewWithTag:30] removeFromSuperview];
    UIView *rightBorder = [[UIView alloc] initWithFrame:CGRectMake(cell.width-1, 0, 1, cell.height)];
    rightBorder.backgroundColor = global.lightGrey;
    rightBorder.tag = 30;
    [cell addSubview:rightBorder];

    //Setting the seletion background color on the cells
    UIView *bgColorView = [[UIView alloc] init];
    bgColorView.backgroundColor = global.extraLightGrey;
    cell.selectedBackgroundView = bgColorView;
    if (global.magazine.issues.count==0) {
        return cell;
    }else if (indexPath.section-1 == global.magazine.issues.count) {
        //Finding the right issue and article for this row
        Issue *issue = [global.magazine.issues objectAtIndex:global.magazine.issues.count-1];

        //Creating the headline
        NSString *headlineString = [NSString stringWithFormat:@"<span class='bold_style'>FOREWORD</span>"];
        NMCustomLabel *headline = [global.label headLineLabelWithString:headlineString fromTop:30 withWidth:global.screenWidth-60];
        headline.tag = 21;
        [cell addSubview:headline];

        //Creating the subHeadline
        NSString *subHeadlineString = [[NSString stringWithFormat:@"%@", issue.magazine_foreword] substringToIndex:100];
        NMCustomLabel *subHeadline = [global.label subHeadlineLabelWithString:subHeadlineString fromTop:30+headline.height+10 withWidth:global.screenWidth-60];
        subHeadline.tag = 22;
        [cell addSubview:subHeadline];

        //Creating byline
        NSString *bylineString = [[NSString stringWithFormat:@"<span class='ital_style'>By %@</span>", issue.magazine_byline] capitalizedString];
        NMCustomLabel *byline = [global.label articleBylineLabelWithString:bylineString fromTop:30+headline.height+10+subHeadline.height+10 withWidth:global.screenWidth-60];
        byline.tag = 23;
        [cell addSubview:byline];
    }else{
        //Finding the right issue and article for this row
        Issue *issue = [global.magazine.issues objectAtIndex:indexPath.section-1];
        Article *article = [issue.articles objectAtIndex:indexPath.row];

        //Creating the headline
        NSString *headlineString = [NSString stringWithFormat:@"<span class='bold_style'>%@</span>", [article.title uppercaseString]];
        NMCustomLabel *headline = [global.label headLineLabelWithString:headlineString fromTop:30 withWidth:global.screenWidth-60];
        headline.tag = 21;
        [cell addSubview:headline];

        //Creating the subHeadline
        NSString *subHeadlineString = [NSString stringWithFormat:@"%@", [article.main_text substringToIndex:100]];
        NMCustomLabel *subHeadline = [global.label subHeadlineLabelWithString:subHeadlineString fromTop:30+headline.height+10 withWidth:global.screenWidth-60];
        subHeadline.tag = 22;
        [cell addSubview:subHeadline];

        //Creating byline
        NSString *bylineString = [[NSString stringWithFormat:@"<span class='ital_style'>By %@</span>", article.byline] capitalizedString];
        NMCustomLabel *byline = [global.label articleBylineLabelWithString:bylineString fromTop:30+headline.height+10+subHeadline.height+10 withWidth:global.screenWidth-60];
        byline.tag = 23;
        [cell addSubview:byline];
    }

    return cell;
}

最佳答案

最简单的解决方案是遵循DRY原理，或者将height作为要用作数据源的对象的属性添加，或者将方法添加到视图控制器中，例如:

-(CGFloat)calculateHeightForHeadline:(NSString*)headline andSubHeadline:(NSString*)subHeadline andByLine:(NSString*)byLine

然后至少您只将计算代码放在一个位置。

或者，您可以从cellForRowAtIndexPath方法调用[tableView heightForRowAtIndexPath:indexPath]

关于iphone - 丑陋的heightForRowAtIndexPath和cellForRowAtIndexPath，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/14889298/