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！
