calayer 没有根据 tableview 单元格中的 UIView 大小而改变答案

【问题标题】：calayer did not change according to UIView size in tableview cellcalayer 没有根据 tableview 单元格中的 UIView 大小而改变
【发布时间】：2023-03-09 15:40:02
【问题描述】：

自定义 UITableViewCell 中有一个 view1(UIView)，我希望在 AutoLayout 之后绘制新尺寸的 view1(UIView) 来绘制边框

UITableViewCell 的内容是动态的，因此我使用了 UITableViewAutomaticDimension 来自动调整大小

我也使用以下方法，但我得到了原始尺寸。展开后我无法获得 view1(UIView) 的新尺寸

[self.tblView1 setNeedsLayout];
[self.tblView1 layoutIfNeeded]; 
[cell.view1 setNeedsLayout];
[cell.view1 layoutIfNeeded];

CALayer *rightBorder = [CALayer layer];
            rightBorder.backgroundColor = [[UIColor redColor] CGColor];
            rightBorder.frame = CGRectMake(cell.view1.frame.size.width-1, 0, 1, cell.view1.frame.size.height);
            [cell.view1.layer addSublayer:rightBorder];

rightBorder 是绘制的，但根据 view1 的（UIView）原始尺寸，即 Width = 394 Height = 322 不根据 view1 的（UIView）新尺寸后的布局尺寸，即 Width = 394 Height = 422

【问题讨论】：

你设置了tableView的estimatedRowHeight属性了吗？
@Rishab 当然是的，兄弟 self.tbl.estimatedRowHeight = 323; self.tbl.rowHeight = UITableViewAutomaticDimension;没有上面的代码，我无法得到动态单元格大小的结果
你是在initWithFrame:里面写代码还是自定义方法？
@Rishab 你在下面的代码中使用 abt 是的，我写了 rightBorder.frame = CGRectMake(cell.view1.frame.size.width-1, 0, 1, cell.view1.frame.size.height );如果不是，那么我应该写什么 initWithFrame
聊天？ chat.stackoverflow.com/rooms/144410/…

标签： ios objective-c uitableview autolayout ios-autolayout

【解决方案1】：

试试这个。

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
if(tableView.tag == self.tblEditorialCalendar.tag)
{

UIView *leftBorder = [UIView new];
leftBorder.backgroundColor = [UIColor redColor];
leftBorder.translatesAutoresizingMaskIntoConstraints = NO;

UIView *topBorder = [UIView new];
topBorder.backgroundColor = [UIColor greenColor];
topBorder.translatesAutoresizingMaskIntoConstraints = NO;

UIView *rightBorder = [UIView new];
rightBorder.backgroundColor = [UIColor blueColor];
rightBorder.translatesAutoresizingMaskIntoConstraints = NO;

UIView *bottomBorder = [UIView new];
bottomBorder.backgroundColor = [UIColor yellowColor];
bottomBorder.translatesAutoresizingMaskIntoConstraints = NO;

[cell addSubview:leftBorder];
[cell addSubview:topBorder];
[cell addSubview:rightBorder];
[cell addSubview:bottomBorder];

[cell addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"H:|[leftBorder(3)]"
                                                             options:0
                                                             metrics:nil
                                                               views:NSDictionaryOfVariableBindings(leftBorder)]];
[cell addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"V:|[leftBorder]|"
                                                             options:0
                                                             metrics:nil
                                                               views:NSDictionaryOfVariableBindings(leftBorder)]];

[cell addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"H:|-3-[topBorder]|"
                                                             options:0
                                                             metrics:nil
                                                               views:NSDictionaryOfVariableBindings(topBorder)]];
[cell addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"V:|[topBorder(1)]"
                                                             options:0
                                                             metrics:nil
                                                               views:NSDictionaryOfVariableBindings(topBorder)]];

[cell addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"H:[rightBorder(1)]|"
                                                             options:0
                                                             metrics:nil
                                                               views:NSDictionaryOfVariableBindings(rightBorder)]];
[cell addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"V:|[rightBorder]|"
                                                             options:0
                                                             metrics:nil
                                                               views:NSDictionaryOfVariableBindings(rightBorder)]];

[cell addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"H:|-3-[bottomBorder]|"
                                                             options:0
                                                             metrics:nil
                                                               views:NSDictionaryOfVariableBindings(bottomBorder)]];
[cell addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"V:[bottomBorder(1)]|"
                                                             options:0
                                                             metrics:nil
                                                               views:NSDictionaryOfVariableBindings(bottomBorder)]];


cell.selectionStyle = UITableViewCellSelectionStyleNone;
return cell;
}

}

另一种方法是使用布局锚（iOS 9 及更高版本支持）而不是 VFL

[leftBorder.widthAnchor constraintEqualToConstant:3].active = YES;
[cell.leadingAnchor constraintEqualToAnchor:leftBorder.leadingAnchor constant:0].active = YES;
[cell.topAnchor constraintEqualToAnchor:leftBorder.topAnchor constant:0].active = YES;
[cell.bottomAnchor constraintEqualToAnchor:leftBorder.bottomAnchor constant:0].active = YES;

[topBorder.heightAnchor constraintEqualToConstant:1].active = YES;
[cell.leadingAnchor constraintEqualToAnchor:topBorder.leadingAnchor constant:3].active = YES;
[cell.topAnchor constraintEqualToAnchor:topBorder.topAnchor constant:0].active = YES;
[cell.trailingAnchor constraintEqualToAnchor:topBorder.trailingAnchor constant:0].active = YES;

[rightBorder.widthAnchor constraintEqualToConstant:1].active = YES;
[cell.trailingAnchor constraintEqualToAnchor:rightBorder.trailingAnchor constant:0].active = YES;
[cell.topAnchor constraintEqualToAnchor:rightBorder.topAnchor constant:0].active = YES;
[cell.bottomAnchor constraintEqualToAnchor:rightBorder.bottomAnchor constant:0].active = YES;

[bottomBorder.heightAnchor constraintEqualToConstant:1].active = YES;
[cell.leadingAnchor constraintEqualToAnchor:bottomBorder.leadingAnchor constant:3].active = YES;
[cell.trailingAnchor constraintEqualToAnchor:bottomBorder.trailingAnchor constant:0].active = YES;
[cell.bottomAnchor constraintEqualToAnchor:bottomBorder.bottomAnchor constant:0].active = YES;

或者您可以只在您的 nib 文件中获取四个视图（作为四个边框）并将它们放置在适当的约束条件下。

【讨论】：