旋转iPhone时重置自定义UITableViewCell高度 [英] Resetting custom UITableViewCell height when iPhone is rotated

问题描述

我正在重载委托方法 -tableView：heightForRowAtIndexPath：并使用 -sizeWithFont：constrainedToSize：以编程方式设置单元格的高度，基于该单元格中的文本：

I am overloading the delegate method -tableView:heightForRowAtIndexPath: and using -sizeWithFont:constrainedToSize: to programmatically set the height of the cell, based on the text in that cell:

- (CGFloat) tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath {
  switch (indexPath.section) {
    case(kAboutViewOverviewSection): {
      switch (indexPath.row) {
        case(kAboutViewOverviewSectionRow): {
          NSString *text = NSLocalizedString(@"kAboutViewOverviewSectionFieldText", @"");
          CGSize s = [text sizeWithFont:[UIFont systemFontOfSize:14] constrainedToSize:CGSizeMake(280, 500)];
          return s.height + 13;
        }
        default: {
          break;
        }
      }
      break;
    }
    default: {
      break;
    }
  }
  return 44.0;
}

这在第一次绘制表时有效。但是，当我更改设备的方向时，从纵向到横向，单元格高度不会改变。

This works when the table is first drawn. However, when I change the orientation of the device, from portrait to landscape, the cell height does not change.

我试图覆盖 -shouldAutorotateToInterfaceOrientation ：我的表视图控制器中的方法：

I tried overriding the -shouldAutorotateToInterfaceOrientation: method in my table view controller:

- (BOOL) shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation {
  [self.tableView reloadData];
  return YES;
}

这应该重新加载表数据并且（可能）重绘表格单元格视图。但这没有任何影响。

This should reload the table data and (presumably) redraw the table cell views. But this does not have any effect.

当设备旋转时，有没有办法强制单元格重新绘制高度？

Is there a way to force a cell to redraw with a new height, when the device is rotated?

编辑：我尝试了以下操作，但没有效果：

EDIT: I have tried the following, to no effect:

- (void) didRotateFromInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation {
  [self.tableView reloadData];
}

这是应用程序在纵向方向的样子：

Here is what the application looks like in portrait orientation:

以下是横向应用程序的样子：

Here is what the application looks like in landscape orientation:

内容的上边缘和下边缘之间存在间隙。

There is a gap between the top and bottom edges of the content.

编辑2 ：

通过表格框架的宽度调整尺寸参数有助于解决此显示问题：

Adjusting the size parameter via the table frame's width helped fix this display issue:

CGSize s = [text sizeWithFont:[UIFont systemFontOfSize:14] constrainedToSize:CGSizeMake([tableView frame].size.width,500)];

推荐答案

这不是最优的，但最简单的解决方案是在桌面上调用 -reloadData 。

It's less than optimal, but the simplest solution is to call -reloadData on the table.

更好的解决方案是调用 -beginUpdates ， -deleteRowsAtIndexPaths：withRowAnimation：， -insertRowsAtIndexPaths：withRowAnimation：，和 -endUpdates 或只是 -reloadSections：withRowAnimation：如果仅定位3.0。这将添加动画。

A better solution would be to call -beginUpdates, -deleteRowsAtIndexPaths:withRowAnimation:, -insertRowsAtIndexPaths:withRowAnimation:, and -endUpdates or simply -reloadSections:withRowAnimation: if targeting 3.0 only. This will add animation.

编辑：你还需要一个正确的 tableView：heightForRowAtIndexPath：

And you will also need a proper tableView:heightForRowAtIndexPath:

- (CGFloat) tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath {
    CGSize textSize = [[self textForRowAtIndexPath:indexPath] sizeWithFont:[UIFont systemFontOfSize:14] constrainedToSize:CGSizeMake([tableView frame].size.width - 20, 500)];
    return textSize.height + 13.0f;
}

（其中 textForRowAtIndexPath：是一个返回单元格文本的方法）

(where textForRowAtIndexPath: is a method that returns the cell's text)

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