- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath {
// check here, if it is one of the cells, that needs to be resized
// to the size of the contained UITextView
if ( )
return [self textViewHeightForRowAtIndexPath:indexPath];
else
// return your normal height here:
return 100.0;
}
- (CGFloat)textViewHeightForRowAtIndexPath: (NSIndexPath*)indexPath {
UITextView *calculationView = [textViews objectForKey: indexPath];
CGFloat textViewWidth = calculationView.frame.size.width;
if (!calculationView.attributedText) {
// This will be needed on load, when the text view is not inited yet
calculationView = [[UITextView alloc] init];
calculationView.attributedText = // get the text from your datasource add attributes and insert here
textViewWidth = 290.0; // Insert the width of your UITextViews or include calculations to set it accordingly
}
CGSize size = [calculationView sizeThatFits:CGSizeMake(textViewWidth, FLT_MAX)];
return size.height;
}
- (void)textViewDidChange:(UITextView *)textView {
[self.tableView beginUpdates]; // This will cause an animated update of
[self.tableView endUpdates]; // the height of your UITableViewCell
// If the UITextView is not automatically resized (e.g. through autolayout
// constraints), resize it here
[self scrollToCursorForTextView:textView]; // OPTIONAL: Follow cursor
}
This will make the UITableView scroll to the position of the cursor, if it is not inside the visible Rect of the UITableView:
- (void)scrollToCursorForTextView: (UITextView*)textView {
CGRect cursorRect = [textView caretRectForPosition:textView.selectedTextRange.start];
cursorRect = [self.tableView convertRect:cursorRect fromView:textView];
if (![self rectVisible:cursorRect]) {
cursorRect.size.height += 8; // To add some space underneath the cursor
[self.tableView scrollRectToVisible:cursorRect animated:YES];
}
}
5. 通过设置插图调整可见直接
While editing, parts of your UITableView may be covered by the Keyboard. If the tableviews insets are not adjusted, scrollToCursorForTextView: will not be able to scroll to your cursor, if it is at the bottom of the tableview.
if (SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO(@"7.0")) {
someTextView.textContainer.heightTracksTextView = YES;
}
正如文档所说,该属性的作用是:
控制接收器是否调整其边界的高度
当其文本视图调整大小时。默认值: NO。
If leave it with the default value, after resize the frame of someTextView, the size of the textContainer is not changed, leading to the result that the text can only be displayed in the area before resizing.
And maybe it is needed to set the scrollEnabled = NO in case there's more than one textContainer, so that the text will reflow from one textContainer to the another.
// This is the method that determines the height of each cell.
- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
{
// I am using a helper method here to get the text at a given cell.
NSString *text = [self getTextAtIndex:indexPath];
// Getting the height needed by the dynamic text view.
CGSize size = [self frameForText:text sizeWithFont:nil constrainedToSize:CGSizeMake(300.f, CGFLOAT_MAX)];
// Return the size of the current row.
// 80 is the minimum height! Update accordingly - or else, cells are going to be too thin.
return size.height + 80;
}
// Think of this as some utility function that given text, calculates how much
// space would be needed to fit that text.
- (CGSize)frameForText:(NSString *)text sizeWithFont:(UIFont *)font constrainedToSize:(CGSize)size
{
NSDictionary *attributesDictionary = [NSDictionary dictionaryWithObjectsAndKeys:
font, NSFontAttributeName,
nil];
CGRect frame = [text boundingRectWithSize:size
options:(NSStringDrawingUsesLineFragmentOrigin | NSStringDrawingUsesFontLeading)
attributes:attributesDictionary
context:nil];
// This contains both height and width, but we really care about height.
return frame.size;
}
// Think of this as a source for the text to be rendered in the text view.
// I used a dictionary to map indexPath to some dynamically fetched text.
- (NSString *) getTextAtIndex: (NSIndexPath *) indexPath
{
return @"This is stubbed text - update it to return the text of the text view.";
}
(2)在 TableCell.m加入:
// This method will be called when the cell is initialized from the storyboard
// prototype.
- (void)awakeFromNib
{
// Assuming TextView here is the text view in the cell.
TextView.scrollEnabled = YES;
}
Explanation:
所以这里发生的是: 每个文本视图通过垂直和水平约束绑定到表单元格的高度-这意味着当表单元格高度增加时,文本视图也会增加其大小。我使用@manecosta 代码的修改版本来计算文本视图所需的高度,以适应单元格中给定的文本。因此,这意味着给定一个具有 X 个字符的文本,frameForText:将返回一个大小,该大小将具有与文本视图所需高度匹配的属性 size.height。