1 - (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
 2 {
 3     MyCell *myCell;
 4     DTAttributedTextCell *dtCell;
 5     if (indexPath.row==0) {
 6         dtCell=(DTAttributedTextCell *)[self tableView:tableView preparedCellForIndexPath:indexPath];
 7         //return  dtCell.attributedTextContextView.frame.size.height+10;
 8         return [dtCell requiredRowHeightInTableView:tableView]+20;
 9     }else{
10         myCell = (MyCell *)[self tableView:tableView preparedCellForIndexPath:indexPath];
11         return  myCell.attributedTextContextView.frame.size.height+10;
12     }
13
14 }
15
16 - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
17 {
18     id cell;
19     if (indexPath.row==0) {
20         cell=(DTAttributedTextCell *)[self tableView:tableView preparedCellForIndexPath:indexPath];
21
22     }else{
23        cell = (MyCell *)[self tableView:tableView preparedCellForIndexPath:indexPath];
24     }
25     return cell;
26 }

 1 - (id)tableView:(UITableView *)tableView preparedCellForIndexPath:(NSIndexPath *)indexPath
 2 {
 3
 4     if (!cellCache)
 5     {
 6         cellCache = [[NSCache alloc] init];
 7     }
 8
 9     // workaround for iOS 5 bug
10     NSString *key = [NSString stringWithFormat:@"%d-%d", indexPath.section, indexPath.row];
11
12     id cell = [cellCache objectForKey:key];
13
14     if (!cell)
15     {
16         // reuse does not work for variable height
17         //cell = (DTAttributedTextCell *)[tableView dequeueReusableCellWithIdentifier:cellIdentifier];
18
19         if (!cell)
20         {
21            //这里面是核心代码   判断是哪个类型 再创建对应的类型
22             if (indexPath.row==0) {
23                 cell = [[DTAttributedTextCell alloc] initWithReuseIdentifier:@"title" accessoryType:UITableViewCellAccessoryDisclosureIndicator];
24
25             }else{
26                 cell=[myTableView dequeueReusableCellWithIdentifier:@"answer"];
27             }
28
29
30         }
31
32         // cache it
33         [cellCache setObject:cell forKey:key];
34     }
35
36     [self configureCell:cell forIndexPath:indexPath];
37
38     return cell;
39 }

 1 - (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
 2     return 5;
 3 }
 4
 5 - (void)configureCell:(id)cell forIndexPath:(NSIndexPath *)indexPath
 6 {
 7     MyCell *myCell;
 8     DTAttributedTextCell *dtCell;
 9     if (indexPath.row==0) {
10         dtCell=(DTAttributedTextCell *)cell;
11         NSString *html=@"摘要: 其实说是DTAttributedTextCell解析并显示html 应该是cell上的DTAttributedTextContentView解析并显示html首先先说一下DTAttributedTextCell 解析显示html的优点a.能够很好的实现cell的自适应高度，用webView也能实现自适应高度,但是逻辑复杂，效率不高，有加";
12        //下面一句是代码的作用后面会解释
13         dtCell.attributedTextContextView.identifier=@"title";
14         [dtCell setHTMLString:html];
15         dtCell.userInteractionEnabled=NO;
16         [dtCell setSelectionStyle:UITableViewCellSelectionStyleNone];
17         dtCell.attributedTextContextView.shouldDrawImages = YES;
18         dtCell.attributedTextContextView.backgroundColor=[UIColor clearColor];
19
20     }
21     else
22     {
23         myCell=(MyCell *)cell;
24         NSString *html=@"V<sub>1</sub>+V<sub>2</sub>=V<sub>13</sub>";
25        //下面代码的作用后面会解释
26         myCell.attributedTextContextView.identifier=@"answer";
27         CGSize size=myCell.attributedTextContextView.frame.size;
28         myCell.attributedTextContextView.realSize=size;
29         [myCell setHTMLString:html];
30        myCell.ABCDlabel.text=@"A";
31         myCell.imageView.image=[UIImage imageNamed:@"answer-notselected"];
32         myCell.attributedTextContextView.backgroundColor=[UIColor clearColor];
33         myCell.attributedTextContextView.shouldDrawImages = YES;
34
35     }
36 }

 1 @interface DTAttributedTextContentView : UIView
 2
 3 {
 4
 5 NSAttributedString *_attributedString;
 6
 7 DTCoreTextLayoutFrame *_layoutFrame;
 8
 9
10
11 UIEdgeInsets edgeInsets;
12
13
14
15 NSMutableDictionary *customViewsForAttachmentsIndex;
16
17 //这是我们自己给其添加的一个属性，用来区分不同的实例
18 NSString *identifier;
19 //这个用来装载不同实例的 frame.size
20 CGSize realSize;
21
22 }
23
24 @property(nonatomic,retain)NSString *identifier;
25
26 @property(nonatomic)CGSize realSize;

1          myCell.attributedTextContextView.identifier=@"answer";
2          CGSize size=myCell.attributedTextContextView.frame.size;
3          myCell.attributedTextContextView.realSize=size;
4          [myCell setHTMLString:html];

 1 - (void)relayoutText
 2 {
 3     //CGRect frame=self.frame;
 4
 5     //下面的代码进行判断  并利用isMyCell设定了一个标志
 6     int isMyCell;
 7     if ([self.identifier isEqualToString:@"answer"]) {
 8         isMyCell=2;
 9     }else if(self.identifier==nil)
10     {
11         isMyCell=3;
12
13     }
14     else if([self.identifier isEqualToString:@"title"])
15     {
16         isMyCell=1;
17     }
18
19     // Make sure we actually have a superview before attempting to relayout the text.
20     if (self.superview) {
21         // need new layouter
22         self.layouter = nil;
23         self.layoutFrame = nil;
24         // remove all links because they might have merged or split
25        [self removeAllCustomViewsForLinks];
26
27         if (_attributedString)
28         {
29             // triggers new layout
30
31             CGSize neededSize;
32            //这里根据isMyCell的值确定 是用的哪个cell再设定一些尺寸相关的代码
33             if (isMyCell==2) {
34                 neededSize = [self sizeThatFits:self.realSize];
35                 self.frame = CGRectMake(152, self.frame.origin.y, neededSize.width, neededSize.height);
36             }
37             else if(isMyCell==1){
38                 neededSize=[self sizeThatFits:self.bounds.size];
39                 super.frame = CGRectMake(self.frame.origin.x, self.frame.origin.y, neededSize.width, neededSize.height);
40             }
41             // set frame to fit text preserving origin
42             // call super to avoid endless loop
43             [self willChangeValueForKey:@"frame"];
44
45             [self didChangeValueForKey:@"frame"];
46         }
47         [self setNeedsDisplay];
48         [self setNeedsLayout];
49     }
50 }