iOS表格绘制cell－往cell.contentView添加子视图

iOS表格绘制cell－往cell.contentView添加子视图

当你动态修改cell中的视图，比如UILabel上的文字、UIImageView的图片、UIButton，必须先删除cell.contentView中自定义的视图，代码：

//删除cell.contentView中新加的视图
        for(UIView *view in [cell.contentView subviews])
        {
            [view removeFromSuperview];
        }

备注：如果不加上面的代码，则表格上下滚动的时候，contentView上的标签、按钮、图片会因为缓存的缘故发生重叠。

#pragma mark - 绘制单元格
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    NSLog(@"-------cellForRowAtIndexPath");
    static NSString *identifier = @"cell_id";
    UITableViewCell* cell = [tableView dequeueReusableCellWithIdentifier:identifier];
    if (!cell) {
        cell = [[UITableViewCell alloc]initWithStyle:UITableViewCellStyleDefault reuseIdentifier:identifier];
    }else{
        //删除cell.contentView中新加的视图
        for(UIView *view in [cell.contentView subviews])
        {
            [view removeFromSuperview];
        }
    }
    cell.selectionStyle = UITableViewCellSelectionStyleNone;
    NSDictionary *option = [_dicData objectForKey:[_categoryArray objectAtIndex:indexPath.section]][indexPath.row];
//    UIView* mainView = [[UIView alloc]initWithFrame:CGRectMake(0, 0, cell.width, cell.height)];
    //时间和联赛
    UILabel* timeAndClubName = [[UILabel alloc]initWithFrame:CGRectMake(0, 12, cell.width, 10)];
    timeAndClubName.text=[NSString stringWithFormat:@"%@ %@",[[option objectForKey:@"time"] substringWithRange:NSMakeRange(11,5)],[option objectForKey:@"name"]];
    [timeAndClubName setFont:[UIFont systemFontOfSize:13]];
    timeAndClubName.textAlignment = NSTextAlignmentCenter;
    timeAndClubName.textColor = [UIColor lightGrayColor];
    //主队和客队
    UIImageView* ivTeam1Icon = [[UIImageView alloc] initWithFrame:CGRectMake(40, 20, 40, 40)];
    [ivTeam1Icon sd_setImageWithURL:[[option objectForKey:@"team1"] objectForKey:@"icon"] placeholderImage:[UIImage imageNamed:KGQ_DEFAULT_FOR_TEAM]];
    
    UIImageView* ivTeam2Icon = [[UIImageView alloc] initWithFrame:CGRectMake(cell.width-80, 20, 40, 40)];
    [ivTeam2Icon sd_setImageWithURL:[[option objectForKey:@"team2"] objectForKey:@"icon"] placeholderImage:[UIImage imageNamed:KGQ_DEFAULT_FOR_TEAM]];
    
    UILabel* lblTeam1Name = [[UILabel alloc]initWithFrame:CGRectMake(0, ivTeam1Icon.bottom +5, 120, 20)];
    lblTeam1Name.text=[[option objectForKey:@"team1"] objectForKey:@"name"];
    lblTeam1Name.textAlignment = NSTextAlignmentCenter;

    UILabel* lblTeam2Name = [[UILabel alloc]initWithFrame:CGRectMake(cell.width-120, ivTeam2Icon.bottom+5 , 120, 20)];
    lblTeam2Name.text=[[option objectForKey:@"team2"] objectForKey:@"name"];
    lblTeam2Name.textAlignment = NSTextAlignmentCenter;

    //关注按钮或比分
    BOOL isAttention = [[option objectForKey:@"attention_state"] isEqualToString:@"0"] ? NO : YES;
    UIButton* btnAttention = [UIButton buttonWithType:UIButtonTypeCustom];
    btnAttention.frame = CGRectMake((cell.width-25)/2, timeAndClubName.bottom +15, 25, 25);
    if (isAttention) {
        [btnAttention setImage:[UIImage imageNamed:@"img_collect"] forState:UIControlStateNormal];
    }else{
        [btnAttention setImage:[UIImage imageNamed:@"img_uncollect"] forState:UIControlStateNormal];
    }
    [btnAttention addTarget:self action:@selector(btnAttentionClick:) forControlEvents:UIControlEventTouchUpInside];

    
    //加入contentView
    [cell.contentView addSubview:btnAttention];
    [cell.contentView addSubview:ivTeam1Icon];
    [cell.contentView addSubview:ivTeam2Icon];
    [cell.contentView addSubview:timeAndClubName];
    [cell.contentView addSubview:lblTeam1Name];
    [cell.contentView addSubview:lblTeam2Name];

    return cell;
}

 问题：如果先定义一个UIView *mainView，然后把上面代码中的标签、按钮、图片视图先全部加到mainView中，然后再把mainView加到cell.contentView上，会发生一个奇怪的问题：运行后，按钮的点击事件不起作用，但是把表格向下或向上滚动拉出更多的cell后，按钮的点击事件又可以使用了！