为啥 UITextView 高度仅在滚动时变为动态？
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【中文标题】为啥 UITextView 高度仅在滚动时变为动态？【英文标题】：Why UITextView height become dynamic only on scroll?为什么 UITextView 高度仅在滚动时变为动态？ 【发布时间】：2015-10-19 13:32:08 【问题描述】：我在UITableCell 中有一个UITextView，我想根据它的大小使其高度动态化。所以我使用了以下代码。
- (void)textViewDidChange:(UITextView *)textView
CGFloat fixedWidth = textView.frame.size.width;
CGSize newSize = [textView sizeThatFits:CGSizeMake(fixedWidth, MAXFLOAT)];
CGRect newFrame = textView.frame;
newFrame.size = CGSizeMake(fmaxf(newSize.width, fixedWidth), newSize.height);
textView.frame = newFrame;
此代码运行良好，但问题是我的 UITextView 高度只有在我滚动时才会变为动态，否则在加载 UITableView 时它不会变为动态高度。虽然方法被调用了两次。请告诉我为什么会这样？
编辑：
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
NSLog(@"cell for row called %d",(int)[arr_post count]);
//define variables here
NSMutableAttributedString *mutableAttributeStr;
NSAttributedString *attributeStr;
static NSString *CellIdentifier = @"homeCell";
HomeCell *cell = [self.table_view
dequeueReusableCellWithIdentifier:CellIdentifier
forIndexPath:indexPath];
[cell setSelectionStyle:UITableViewCellSelectionStyleNone];
//get the post data
Post *user_post=[arr_post objectAtIndex:indexPath.row];
//set the button tags
cell.btn_like.tag=indexPath.row;
cell.btn_comment.tag=indexPath.row;
cell.btn_fav.tag=indexPath.row;
cell.btn_con.tag=indexPath.row;
cell.btn_book.tag=indexPath.row;
//add info to buttons
cell.btn_like.selected=user_post.isPostLiked;
cell.btn_comment.selected=user_post.isPostCommented;
cell.btn_fav.selected=user_post.isPostFavourite;
cell.btn_con.selected=user_post.isPostCondolence;
cell.btn_book.selected=user_post.isPostBookmarked;
//add text view path
//add user info
cell.label_name.text=user_post.username;
[cell.img_profile setImageWithURL:[NSURL URLWithString:[IMAGE_BASE_URL stringByAppendingString:user_post.user_profileImage]]placeholderImage:[UIImage imageNamed:@"post_placeholder.png"]];
//add location
if([user_post.location isEqualToString:@"Not Available"])
[cell.img_icon_location setHidden:true];
[cell.label_location setHidden:true];
else
cell.label_location.text=user_post.location;
//ad post info
cell.tv_post.text=user_post.post_description;
cell.tv_post.font = [UIFont fontWithName:user_post.font_family size:[user_post.font_size floatValue]];
NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
[formatter setDateFormat:@"yyyy-MM-dd HH:mm:ss"];
NSDate *date = [formatter dateFromString:user_post.modification_date];
if([user_post.post_image isEqualToString:@"none"] && [user_post.post_video isEqualToString:@"none"])
else
UIBezierPath * imgRect = [UIBezierPath bezierPathWithRect:CGRectMake(0, 10, 100, 100)];
cell.tv_post.textContainer.exclusionPaths = @[imgRect];
UIImageView *tv_image =[[UIImageView alloc]initWithFrame:CGRectMake(0, 10, 100, 100)];
[tv_image setImageWithURL:[NSURL URLWithString:[IMAGE_BASE_URL stringByAppendingString:user_post.post_video_thumbnail]]placeholderImage:[UIImage imageNamed:@"post_placeholder.png"]];
[cell.tv_post addSubview:tv_image];
//make textview height dynamic
cell.tv_post.scrollEnabled=NO;
[self textViewDidChange:cell.tv_post];
NSLog(@"textview height is %f",cell.tv_post.frame.size.height);
NSLog(@"main view height is %f",cell.view_tvContainer.frame.size.height);
//set the border of uiview
cell.view_tvContainer.layer.borderColor = [UIColor blackColor].CGColor;
cell.view_tvContainer.layer.borderWidth = 2.0f;
//set the like count
NSString *first_like_user=user_post.recent_like_name;
int count=(int)[first_like_user length];
int like_count=[user_post.like_count intValue];
//chek if tehre are any likes on the post
NSLog(@"post id is %@",user_post.id);
NSLog(@"recent like name is %@",user_post.recent_like_name);
NSLog(@"like count is %d",like_count);
if(like_count>0)
NSLog(@"inside like count block");
cell.label_like_count.lineBreakMode=NSLineBreakByWordWrapping;
[cell.label_like_count sizeToFit];
[cell.label_like_count setHidden:false];
NSString *str_like_count=[NSString stringWithFormat:@"%lu",(unsigned long)like_count-1];
if(like_count==1)
if([myUsername isEqualToString:first_like_user])
first_like_user=@"You asjlike sdfsdfsd sfd ";
count=3;
else
first_like_user=[first_like_user stringByAppendingString:@" like this post"];
else if(like_count==2)
first_like_user=[first_like_user stringByAppendingString:@" and "];
str_like_count=[str_like_count stringByAppendingString:@" other like this post"];
first_like_user=[first_like_user stringByAppendingString:str_like_count];
else
if(like_count>1000)
like_count=like_count/1000;
str_like_count=[NSString stringWithFormat:@"%lu",(unsigned long)like_count];
str_like_count=[str_like_count stringByAppendingString:@"k"];
first_like_user=[first_like_user stringByAppendingString:@" and "];
str_like_count=[str_like_count stringByAppendingString:@" others like this post"];
first_like_user=[first_like_user stringByAppendingString:str_like_count];
else
first_like_user=[first_like_user stringByAppendingString:@" and "];
str_like_count=[str_like_count stringByAppendingString:@" others like this post"];
first_like_user=[first_like_user stringByAppendingString:str_like_count];
mutableAttributeStr = [[NSMutableAttributedString alloc]initWithString:first_like_user];
attributeStr = [[NSAttributedString alloc]initWithString:@"\n" attributes:@NSFontAttributeName : [UIFont fontWithName:@"HelveticaNeue-Bold" size:8]];
[mutableAttributeStr addAttribute:NSFontAttributeName value: [UIFont fontWithName:@"Helvetica-Bold" size:14.0] range:NSMakeRange(0, count)];
[mutableAttributeStr addAttribute:NSForegroundColorAttributeName value:[self colorFromHexString:@"#48a0dd"] range:NSMakeRange(0, count)];
[mutableAttributeStr appendAttributedString:attributeStr];
[cell.label_like_count setAttributedText:mutableAttributeStr];
else
NSLog(@"not inside like count");
[cell.label_like_count setHidden:true];
// show dynamic comment
NSMutableArray *user_comments=user_post.comments;
float comment_count=[user_post.comment_count intValue];
NSLog(@"post id is %@",user_post.id);
NSLog(@"arr comments count is %lu",(unsigned long)comment_count);
NSLog(@"arr user comments count is %lu",[user_comments count]);
if(comment_count>0)
NSLog(@"post id is %@",user_post.id);
//make label multiline
cell.first_comment.lineBreakMode=NSLineBreakByWordWrapping;
[cell.first_comment sizeToFit];
cell.second_cmment.lineBreakMode=NSLineBreakByWordWrapping;
[cell.second_cmment sizeToFit];
cell.third_comment.lineBreakMode=NSLineBreakByWordWrapping;
[cell.third_comment sizeToFit];
NSMutableAttributedString *mutableAttributeStr;
NSAttributedString *attributeStr;
if(comment_count==1)
[cell.first_comment setHidden:false];
[cell.second_cmment setHidden:true];
[cell.third_comment setHidden:true];
else if(comment_count==2)
[cell.first_comment setHidden:false];
[cell.second_cmment setHidden:false];
[cell.third_comment setHidden:true];
else
[cell.first_comment setHidden:false];
[cell.second_cmment setHidden:false];
[cell.third_comment setHidden:false];
[cell.btn_more_comments setHidden:false];
for(l=0;l<[user_comments count];l++)
NSLog(@"inside loop %d",l);
Comment *comment=[user_comments objectAtIndex:l];
NSLog(@"comment is %@",comment.comment);
NSLog(@"comment user is %@",comment.user_name);
if(l==0)
NSLog(@"l is zero");
NSString *comment_string=[comment.user_name stringByAppendingString:@" "];
comment_string=[comment_string stringByAppendingString:comment.comment];
int count=(int)[comment.user_name length];
mutableAttributeStr = [[NSMutableAttributedString alloc]initWithString:comment_string];
NSLog(@"comment string is %@",comment_string);
attributeStr = [[NSAttributedString alloc]initWithString:@"\n" attributes:@NSFontAttributeName : [UIFont fontWithName:@"HelveticaNeue-Bold" size:8]];
[mutableAttributeStr addAttribute:NSFontAttributeName value: [UIFont fontWithName:@"Helvetica-Bold" size:14.0] range:NSMakeRange(0, count)];
[mutableAttributeStr addAttribute:NSForegroundColorAttributeName value:[self colorFromHexString:@"#48a0dd"] range:NSMakeRange(0, count)];
[mutableAttributeStr appendAttributedString:attributeStr];
[cell.first_comment setAttributedText:mutableAttributeStr];
else if(l==1)
NSLog(@"l is 1");
NSString *comment_string=[comment.user_name stringByAppendingString:@" "];
comment_string=[comment_string stringByAppendingString:comment.comment];
int count=(int)[comment.user_name length];
mutableAttributeStr = [[NSMutableAttributedString alloc]initWithString:comment_string];
attributeStr = [[NSAttributedString alloc]initWithString:@"\n" attributes:@NSFontAttributeName : [UIFont fontWithName:@"HelveticaNeue-Bold" size:8]];
[mutableAttributeStr addAttribute:NSFontAttributeName value: [UIFont fontWithName:@"Helvetica-Bold" size:14.0] range:NSMakeRange(0, count)];
[mutableAttributeStr addAttribute:NSForegroundColorAttributeName value:[self colorFromHexString:@"#48a0dd"] range:NSMakeRange(0, count)];
NSLog(@"comment string is %@",comment_string);
[mutableAttributeStr appendAttributedString:attributeStr];
[cell.second_cmment setAttributedText:mutableAttributeStr];
else if(l==2)
NSLog(@"l is 2");
NSString *comment_string=[comment.user_name stringByAppendingString:@" "];
comment_string=[comment_string stringByAppendingString:comment.comment];
int count=(int)[comment.user_name length];
mutableAttributeStr = [[NSMutableAttributedString alloc]initWithString:comment_string];
attributeStr = [[NSAttributedString alloc]initWithString:@"\n" attributes:@NSFontAttributeName : [UIFont fontWithName:@"HelveticaNeue-Bold" size:8]];
[mutableAttributeStr addAttribute:NSFontAttributeName value: [UIFont fontWithName:@"Helvetica-Bold" size:14.0] range:NSMakeRange(0, count)];
[mutableAttributeStr addAttribute:NSForegroundColorAttributeName value:[self colorFromHexString:@"#48a0dd"] range:NSMakeRange(0, count)];
[mutableAttributeStr appendAttributedString:attributeStr];
[cell.third_comment setAttributedText:mutableAttributeStr];
else
[cell.first_comment setHidden:true];
[cell.second_cmment setHidden:true];
[cell.third_comment setHidden:true];
[cell.btn_more_comments removeFromSuperview];
cell.label_time.text=[BaseController getTimestampForDate:date];
[arr_indexpath addObject:indexPath];
return cell;
【问题讨论】：
为 rowatIndexpath 方法显示您的单元格 heightForRowAtIndexPath 方法中有什么？ 请检查我的更新代码 天哪，你的方法太大了。我在寻找文本视图时迷路了。 对不起，我只有这个 【参考方案1】：试试这个。
-(void)dynamicTextSize
UITextView *textView = [[UITextView alloc]initWithFrame:CGRectMake(200, 300, 200, 30)];
textView.center = self.view.center;
[self.view addSubview:textView];
NSString *string = @"You long text here";
textView.text = string;
//UIFont *font = [UIFont fontWithName:@"Arial" size:16.0f];
NSDictionary *attrDict = [NSDictionary dictionaryWithObjectsAndKeys:textView.font, NSFontAttributeName, nil];
textView.backgroundColor = [UIColor lightGrayColor];
CGRect frame = [textView.text boundingRectWithSize:CGSizeMake(textView.frame.size.width, 10000) options:NSStringDrawingTruncatesLastVisibleLine|NSStringDrawingUsesLineFragmentOrigin attributes:attrDict context:nil];
CGRect mFrame = textView.frame;
mFrame.size.width = frame.size.width;
mFrame.size.height = frame.size.height;
textView.frame = mFrame;
//NSLog(@"frame2:%@",NSStringFromCGRect(textView.frame));
【讨论】：
我可以改变 textview 的高度，但为什么这只发生在滚动上？【参考方案2】：尝试致电[cell layoutIfNeeded];并将self.table_view替换为tabelview。这可能会解决您的问题
【讨论】：
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