IOS高访微信聊天对话界面(sizeWithFont:constrainedToSize和stretchableImageWithLeftCapWidth的使用)

大家好，百忙之中，抽出点空，写个微博，话说好久没写。

最近项目中有碰到写类似微信聊天界面上的效果，特整理了一下，写了一个小的Demo，希望给没头绪的同学们一个参考！

下载地址：http://files.cnblogs.com/ios8/WeixinDeom.zip

Demo下载地址：http://download.csdn.net/detail/rhljiayou/6524347

先看一下效果图：左图为截取微信的，右图是本demo的效果

     

再看一下主要代码实现：

1. @implementation ViewController
2. - (void)viewDidLoad
3. {
4. [super viewDidLoad];
5. NSDictionary *dict = [NSDictionary dictionaryWithObjectsAndKeys:@"weixin",@"name",@"微信团队欢迎你。很高兴你开启了微信生活，期待能为你和朋友们带来愉快的沟通体检。",@"content", nil];
6. NSDictionary *dict1 = [NSDictionary dictionaryWithObjectsAndKeys:@"rhl",@"name",@"hello",@"content", nil];
7. NSDictionary *dict2 = [NSDictionary dictionaryWithObjectsAndKeys:@"rhl",@"name",@"0",@"content", nil];
8. NSDictionary *dict3 = [NSDictionary dictionaryWithObjectsAndKeys:@"weixin",@"name",@"谢谢反馈，已收录。",@"content", nil];
9. NSDictionary *dict4 = [NSDictionary dictionaryWithObjectsAndKeys:@"rhl",@"name",@"0",@"content", nil];
10. NSDictionary *dict5 = [NSDictionary dictionaryWithObjectsAndKeys:@"weixin",@"name",@"谢谢反馈，已收录。",@"content", nil];
11. NSDictionary *dict6 = [NSDictionary dictionaryWithObjectsAndKeys:@"rhl",@"name",@"大数据测试，长数据测试，大数据测试，长数据测试，大数据测试，长数据测试，大数据测试，长数据测试，大数据测试，长数据测试，大数据测试，长数据测试。",@"content", nil];
12. _resultArray = [NSMutableArray arrayWithObjects:dict,dict1,dict2,dict3,dict4,dict5,dict6, nil];
13. }
14. - (void)didReceiveMemoryWarning
15. {
16. [super didReceiveMemoryWarning];
17. // Dispose of any resources that can be recreated.
18. }
19. //泡泡文本
20. - (UIView *)bubbleView:(NSString *)text from:(BOOL)fromSelf withPosition:(int)position{
21. //计算大小
22. UIFont *font = [UIFont systemFontOfSize:14];
23. CGSize size = [text sizeWithFont:font constrainedToSize:CGSizeMake(180.0f, 20000.0f) lineBreakMode:NSLineBreakByWordWrapping];
24. // build single chat bubble cell with given text
25. UIView *returnView = [[UIView alloc] initWithFrame:CGRectZero];
26. returnView.backgroundColor = [UIColor clearColor];
27. //背影图片
28. UIImage *bubble = [UIImage imageWithContentsOfFile:[[NSBundle mainBundle] pathForResource:fromSelf?@"SenderAppNodeBkg_HL":@"ReceiverTextNodeBkg" ofType:@"png"]];
29. UIImageView *bubbleImageView = [[UIImageView alloc] initWithImage:[bubble stretchableImageWithLeftCapWidth:floorf(bubble.size.width/2) topCapHeight:floorf(bubble.size.height/2)]];
30. NSLog(@"%f,%f",size.width,size.height);
31. //添加文本信息
32. UILabel *bubbleText = [[UILabel alloc] initWithFrame:CGRectMake(fromSelf?15.0f:22.0f, 20.0f, size.width+10, size.height+10)];
33. bubbleText.backgroundColor = [UIColor clearColor];
34. bubbleText.font = font;
35. bubbleText.numberOfLines = 0;
36. bubbleText.lineBreakMode = NSLineBreakByWordWrapping;
37. bubbleText.text = text;
38. bubbleImageView.frame = CGRectMake(0.0f, 14.0f, bubbleText.frame.size.width+30.0f, bubbleText.frame.size.height+20.0f);
39. if(fromSelf)
40. returnView.frame = CGRectMake(320-position-(bubbleText.frame.size.width+30.0f), 0.0f, bubbleText.frame.size.width+30.0f, bubbleText.frame.size.height+30.0f);
41. else
42. returnView.frame = CGRectMake(position, 0.0f, bubbleText.frame.size.width+30.0f, bubbleText.frame.size.height+30.0f);
43. [returnView addSubview:bubbleImageView];
44. [returnView addSubview:bubbleText];
45. return returnView;
46. }
47. //泡泡语音
48. - (UIView *)yuyinView:(NSInteger)logntime from:(BOOL)fromSelf withIndexRow:(NSInteger)indexRow  withPosition:(int)position{
49. //根据语音长度
50. int yuyinwidth = 66+fromSelf;
51. UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
52. button.tag = indexRow;
53. if(fromSelf)
54. button.frame =CGRectMake(320-position-yuyinwidth, 10, yuyinwidth, 54);
55. else
56. button.frame =CGRectMake(position, 10, yuyinwidth, 54);
57. //image偏移量
58. UIEdgeInsets imageInsert;
59. imageInsert.top = -10;
60. imageInsert.left = fromSelf?button.frame.size.width/3:-button.frame.size.width/3;
61. button.imageEdgeInsets = imageInsert;
62. [button setImage:[UIImage imageNamed:fromSelf?@"SenderVoiceNodePlaying":@"ReceiverVoiceNodePlaying"] forState:UIControlStateNormal];
63. UIImage *backgroundImage = [UIImage imageNamed:fromSelf?@"SenderVoiceNodeDownloading":@"ReceiverVoiceNodeDownloading"];
64. backgroundImage = [backgroundImage stretchableImageWithLeftCapWidth:20 topCapHeight:0];
65. [button setBackgroundImage:backgroundImage forState:UIControlStateNormal];
66. UILabel *label = [[UILabel alloc]initWithFrame:CGRectMake(fromSelf?-30:button.frame.size.width, 0, 30, button.frame.size.height)];
67. label.text = [NSString stringWithFormat:@"%d''",logntime];
68. label.textColor = [UIColor grayColor];
69. label.font = [UIFont systemFontOfSize:13];
70. label.textAlignment = NSTextAlignmentCenter;
71. label.backgroundColor = [UIColor clearColor];
72. [button addSubview:label];
73. return button;
74. }
75. #pragma UITableView
76. - (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
77. {
78. return 1;
79. }
80. -(NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
81. {
82. return _resultArray.count;
83. }
84. -(CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
85. {
86. NSDictionary *dict = [_resultArray objectAtIndex:indexPath.row];
87. UIFont *font = [UIFont systemFontOfSize:14];
88. CGSize size = [[dict objectForKey:@"content"] sizeWithFont:font constrainedToSize:CGSizeMake(180.0f, 20000.0f) lineBreakMode:NSLineBreakByWordWrapping];
89. return size.height+44;
90. }
91. - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
92. {
93. static NSString *CellIdentifier = @"Cell";
94. UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
95. if (cell == nil) {
96. cell = [[UITableViewCell alloc]initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];
97. cell.selectionStyle = UITableViewCellSelectionStyleNone;
98. }else{
99. for (UIView *cellView in cell.subviews){
100. [cellView removeFromSuperview];
101. }
102. }
103. NSDictionary *dict = [_resultArray objectAtIndex:indexPath.row];
104. //创建头像
105. UIImageView *photo ;
106. if ([[dict objectForKey:@"name"]isEqualToString:@"rhl"]) {
107. photo = [[UIImageView alloc]initWithFrame:CGRectMake(320-60, 10, 50, 50)];
108. [cell addSubview:photo];
109. photo.image = [UIImage imageNamed:@"photo1"];
110. if ([[dict objectForKey:@"content"] isEqualToString:@"0"]) {
111. [cell addSubview:[self yuyinView:1 from:YES withIndexRow:indexPath.row withPosition:65]];
112. }else{
113. [cell addSubview:[self bubbleView:[dict objectForKey:@"content"] from:YES withPosition:65]];
114. }
115. }else{
116. photo = [[UIImageView alloc]initWithFrame:CGRectMake(10, 10, 50, 50)];
117. [cell addSubview:photo];
118. photo.image = [UIImage imageNamed:@"photo"];
119. if ([[dict objectForKey:@"content"] isEqualToString:@"0"]) {
120. [cell addSubview:[self yuyinView:1 from:NO withIndexRow:indexPath.row withPosition:65]];
121. }else{
122. [cell addSubview:[self bubbleView:[dict objectForKey:@"content"] from:NO withPosition:65]];
123. }
124. }
125. return cell;
126. }
127. - (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
128. {
129. }
130. @end

其实很简单，主要说一下两个知识点，重要的两个知识点就能写出完美的泡泡对话聊天！

第一个是NSString中的一个方法：

- (CGSize)sizeWithFont:(UIFont *)font constrainedToSize:(CGSize)size lineBreakMode:(NSLineBreakMode)lineBreakMode;

根据文本内容，算出所需要的大小CGSize；

第二个是UIImage中的一个方法：

- (UIImage *)stretchableImageWithLeftCapWidth:(NSInteger)leftCapWidth topCapHeight:(NSInteger)topCapHeight;

这里有几遍文章供大家参考这个方法的使用：
http://blog.csdn.net/lixing333/article/details/7589281

http://blog.csdn.net/w122079514/article/details/7848980

http://www.cnblogs.com/bandy/archive/2012/04/25/2469369.html

ok！完美，perfect！