自定义UITableViewCell视图消失，自动向右移动

Question

现在已经打了好几天了。问题是，当我使用自动布局约束并在UITableViewCell的右边缘对齐视图时，视图会消失。下面是重现问题的代码，但我已经尝试了很多其他的东西，比如各种各样的“needsLayout”，“needsUpdateContraints”等，以及它们各自的“updateLayoutIfNeeded”调用。我也尝试重写“updateConstraints”并在那里添加约束。但无论我做什么，我都会得到完全相同的结果。

-(NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section{
    return 2;
}

-(UITableViewCell*)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{
    NSString* SimpleIdentifier=@"Simple";
    UITableViewCell* cell = [tableView dequeueReusableCellWithIdentifier:SimpleIdentifier];
tableView.translatesAutoresizingMaskIntoConstraints=NO;

    UILabel* label1;
    UILabel* label2;

    if(cell==nil){
        cell=[[UITableViewCell alloc]initWithStyle:UITableViewCellStyleDefault reuseIdentifier:SimpleIdentifier];

        label1=[[UILabel alloc]initWithFrame:CGRectMake(0, 0, 100, 50)];
        label1.tag=100;
        label1.translatesAutoresizingMaskIntoConstraints=NO;
        [cell.contentView addSubview:label1];

        label2=[[UILabel alloc]initWithFrame:CGRectMake(100, 0, 100, 50)];
        label2.tag=101;
        label2.translatesAutoresizingMaskIntoConstraints=NO;
        [cell.contentView addSubview:label2];

        NSDictionary* viewsDictionary=@{@"label1":label1,@"label2":label2};
        [cell.contentView addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"H:|[label1]" options:NSLayoutFormatAlignAllTop metrics:nil views:viewsDictionary]];
        [cell.contentView addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"H:[label2]|" options:NSLayoutFormatAlignAllTop metrics:nil views:viewsDictionary]];
        //[cell.contentView addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"H:|[label1]-[label2]" options:NSLayoutFormatAlignAllTop metrics:nil views:viewsDictionary]];
    } else {
        label1=(UILabel*)[cell.contentView viewWithTag:100];
        label1=(UILabel*)[cell.contentView viewWithTag:101];
    }

    label1.text=@"Label 1";
    label2.text=@"Label 2";

    return cell;
}

Answer 1

-(UITableViewCell*)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{
NSString* SimpleIdentifier=@"Simple";
UITableViewCell* cell = [tableView dequeueReusableCellWithIdentifier:SimpleIdentifier];

UILabel* label1;
UILabel* label2;

if(cell==nil){
    cell=[[UITableViewCell alloc]initWithStyle:UITableViewCellStyleDefault reuseIdentifier:SimpleIdentifier];

    label1=[[UILabel alloc]initWithFrame:CGRectMake(0, 0, 100, 50)];
    label1.tag=100;
    label1.translatesAutoresizingMaskIntoConstraints=NO;
    [cell.contentView addSubview:label1];

    label2=[[UILabel alloc]initWithFrame:CGRectMake(100, 0, 100, 50)];
    label2.tag=101;
    label2.translatesAutoresizingMaskIntoConstraints=NO;
    [cell.contentView addSubview:label2];

    NSDictionary* viewsDictionary=@{@"label1":label1,@"label2":label2};
    [cell.contentView addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"H:|[label1]" options:NSLayoutFormatAlignAllTop metrics:nil views:viewsDictionary]];
    [cell.contentView addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"H:[label2]|" options:NSLayoutFormatAlignAllTop metrics:nil views:viewsDictionary]];
    [cell.contentView addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"V:|[label1]|" options:0 metrics:nil views:viewsDictionary]];
      [cell.contentView addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"V:|[label2]|" options:0 metrics:nil views:viewsDictionary]];

} else {
    label1=(UILabel*)[cell.contentView viewWithTag:100];
    label1=(UILabel*)[cell.contentView viewWithTag:101];
}

label1.text=@"Label 1";
label2.text=@"Label 2";

return cell;

}

截图