iOS开发——使用Autolayout生成动态高度的TableViewCell单元格
步骤一、TableViewCell中使用Autolayout
要点：Cell的高度必须在Constraints中指明，但不能定死，需要让内部由内容决定高度的View决定动态高度。
如UILabel设置numberOfLines为0，设置好左右约束和上下相对位置的约束后就可以让Label的内在高度尺寸约束决定Label的高，即可让系统推断出整个cell的高。
步骤二、在Controller中设置TableView的属性
要点：
self.tableView.estimatedRowHeight = 54;//54为你估算的每个单元格的平均行高，方便系统计算滚动条大小等动作
self.tableView.rowHeight = UITableViewAutomaticDimension;//实际值为-1,让系统自动计算Cell的行高。
样例代码：(使用Masonry第三方Autolayout库)
Cell：
1: //
2: // NewsCell.h
3: // M04P20-新闻
4: //
5: // Created by 张泽阳 on 4/26/15.
6: // Copyright (c) 2015 张泽阳. All rights reserved.
7: //
8:
9: #import <UIKit/UIKit.h>
10: @class News;
11: @interface NewsCell : UITableViewCell
12:
13: @property (nonatomic,strong) UILabel* newsTitleLabel;
14: @property (nonatomic,strong) UILabel* newsAuthorLabel;
15: @property (nonatomic,strong) UILabel* newsCommentsLabel;
16: @property (nonatomic,strong) UIImageView* pictureImageView;
17: -(void)setContentData:(News*)news;
18: +(instancetype)newsCellWithTableView:(UITableView*)tableView;
19: @end
20:
21:
22: //
23: // NewsCell.m
24: // M04P20-新闻
25: //
26: // Created by 张泽阳 on 4/26/15.
27: // Copyright (c) 2015 张泽阳. All rights reserved.
28: //
29:
30: #import "NewsCell.h"
31: #import "News.h"
32: #import "Masonry.h"
33: @implementation NewsCell
34:
35: /**
36: * 懒加载
37: */
38: -(UILabel *)newsCommentsLabel{
39: if (!_newsCommentsLabel) {
40: _newsCommentsLabel = [[UILabel alloc]init];
41: }
42: return _newsCommentsLabel;
43: }
44: -(UILabel *)newsTitleLabel{
45: if (!_newsTitleLabel) {
46: _newsTitleLabel = [[UILabel alloc]init];
47:
48: }
49: return _newsTitleLabel;
50: }
51: -(UILabel *)newsAuthorLabel{
52: if (!_newsAuthorLabel) {
53: _newsAuthorLabel = [[UILabel alloc]init];
54: [self.contentView addSubview:_newsAuthorLabel];
55: }
56: return _newsAuthorLabel;
57: }
58: -(UIImageView *)pictureImageView{
59: if (!_pictureImageView) {
60: _pictureImageView = [[UIImageView alloc]init];
61: }
62: return _pictureImageView;
63: }
64: /**
65: * 便利构造器
66: */
67: +(instancetype)newsCellWithTableView:(UITableView *)tableView{
68: static NSString* ID = @"news";
69: NewsCell* cell = [tableView dequeueReusableCellWithIdentifier:ID];
70: if (!cell) {
71: cell = [[NewsCell alloc]initWIthTableView:tableView andID:ID];
72: }
73:
74: [cell setNeedsLayout];
75: [cell layoutIfNeeded];
76: return cell;
77: }
78: /**
79: * init中设置相对固定的数据
80: *
81: */
82: -(instancetype)initWIthTableView:(UITableView*)tablview andID:(NSString*)ID{
83: // static NSString* ID = @"news";
84: self = [super initWithStyle:UITableViewCellStyleDefault reuseIdentifier:ID];//别忘了super init
85: [self.contentView addSubview:self.newsTitleLabel];
86: [self.contentView addSubview:self.newsAuthorLabel];
87: [self.contentView addSubview:self.pictureImageView];
88: [self.contentView addSubview:self.newsCommentsLabel];
89:
90: self.newsCommentsLabel.textColor = [UIColor grayColor];
91: self.newsCommentsLabel.font = [UIFont systemFontOfSize:12];
92: [self.newsCommentsLabel setHighlightedTextColor:[UIColor whiteColor]];
93: self.newsAuthorLabel.textColor = [UIColor grayColor];
94: self.newsAuthorLabel.font = [UIFont systemFontOfSize:12];
95: [self.newsAuthorLabel setHighlightedTextColor:[UIColor whiteColor]];
96:
97: self.newsTitleLabel.font = [UIFont boldSystemFontOfSize:15];
98: self.newsTitleLabel.numberOfLines = 0;
99:
100: [self.newsTitleLabel setHighlightedTextColor:[UIColor whiteColor]];
101: self.pictureImageView.contentMode = UIViewContentModeScaleAspectFit;
102:
103: return self;
104: }
105: /**
106: * 设置相对动态的数据
107: */
108: -(void)setContentData:(News *)news{
109: self.newsTitleLabel.text = news.title;
110: self.newsAuthorLabel.text = news.author;
111: self.newsCommentsLabel.text = [NSString stringWithFormat:@"评论：%d",news.comments];
112: self.pictureImageView.image = [UIImage imageNamed:news.icon];
113: }
114: /**
115: * 设置布局 记得调用super
116: */
117: -(void)layoutSubviews{
118: [super layoutSubviews];
119: [self.newsTitleLabel mas_makeConstraints:^(MASConstraintMaker *make){
120: make.top.equalTo(self.contentView.mas_top).mas_offset(8); ///offset???
121: make.left.equalTo(self.contentView.mas_left).mas_offset(8);
122: make.right.equalTo(self.pictureImageView.mas_left).mas_offset(-8);
123: }];
124:
125: [self.newsAuthorLabel mas_makeConstraints:^(MASConstraintMaker *make){
126: make.left.equalTo(self.newsTitleLabel);
127: make.top.greaterThanOrEqualTo(self.newsTitleLabel.mas_bottom).mas_offset(8);
128: make.bottom.equalTo(self.contentView.mas_bottom).mas_offset(-8);
129: }];
130:
131: [self.newsCommentsLabel mas_makeConstraints:^(MASConstraintMaker *make){
132: make.top.equalTo(self.newsAuthorLabel.mas_top);
133: make.right.equalTo(self.pictureImageView.mas_left).mas_offset(-8);
134: }];
135:
136: [self.pictureImageView mas_makeConstraints:^(MASConstraintMaker *make){
137: make.top.equalTo(self.contentView.mas_top).mas_offset(8);
138: make.right.equalTo(self.contentView.mas_right).mas_offset(-8);
139: make.bottom.equalTo(self.contentView.mas_bottom).mas_offset(-8);
140: make.width.mas_equalTo(120);
141: }];
142: }
143: /**
144: * 单元格被选中/取消选中时的表现
145: */
146: -(void)setSelected:(BOOL)selected animated:(BOOL)animated{
147: [super setSelected:selected animated:animated];
148: // self.newsTitleLabel.textColor = selected?([UIColor whiteColor]):([UIColor blackColor]);
149: // self.newsAuthorLabel.textColor = selected?([UIColor whiteColor]):([UIColor blackColor]);
150: // self.newsCommentsLabel.textColor = selected?([UIColor whiteColor]):([UIColor blackColor]);
151: }
152: @end
Controller中：
1: //
2: // ViewController.h
3: // M04P20-新闻
4: //
5: // Created by 张泽阳 on 4/26/15.
6: // Copyright (c) 2015 张泽阳. All rights reserved.
7: //
8:
9: #import <UIKit/UIKit.h>
10:
11: @interface ViewController : UIViewController
12: @property (nonatomic,strong) NSArray* newses;
13:
14: @end
15:
16:
17: //
18: // ViewController.m
19: // M04P20-新闻
20: //
21: // Created by 张泽阳 on 4/26/15.
22: // Copyright (c) 2015 张泽阳. All rights reserved.
23: //
24:
25: #import "ViewController.h"
26: #import "News.h"
27: #import "NewsCell.h"
28: #import "NSObject+NSObject_ZZYMODEL.h"
29: @interface ViewController ()<UITableViewDelegate,UITableViewDataSource>
30: @property (weak, nonatomic) IBOutlet UITableView *tableView;
31:
32: @end
33:
34: @implementation ViewController
35: -(NSArray *)newses{
36: if (!_newses) {
37: _newses = [News modelArrayWithFilename:@"news.plist"];
38: }
39: return _newses;
40: }
41: - (void)viewDidLoad {
42: [super viewDidLoad];
43: self.tableView.estimatedRowHeight = 54;
44: self.tableView.rowHeight = UITableViewAutomaticDimension;
45: [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(orientationDidRotate) name:UIApplicationDidChangeStatusBarOrientationNotification object:nil];
46: }
47: -(BOOL)prefersStatusBarHidden{
48: return YES;
49: }
50: -(void)orientationDidRotate{
51: [self.tableView reloadData];
52: }
53: -(NSInteger)numberOfSectionsInTableView:(UITableView *)tableView{
54: return 1;
55: }
56:
57: -(NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section{
58: return self.newses.count;
59: }
60:
61: -(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{
62: NewsCell* cell = [NewsCell newsCellWithTableView:tableView];
63: [cell setContentData:self.newses[indexPath.row]];
64:
65:
66: return cell;
67:
68: }
69:
70:
71:
72:
73: @end
参考连接：
http://www.mgenware.com/blog/?p=507
http://blog.163.com/china_uv/blog/static/1171372672014111681232340/