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：

//
//  NewsCell.h
//  M04P20-新闻
//
//  Created by 张泽阳 on 4/26/15.
//  Copyright (c) 2015 张泽阳. All rights reserved.
//

#import <UIKit/UIKit.h>
@class News;
@interface NewsCell : UITableViewCell

@property (nonatomic,strong) UILabel* newsTitleLabel;
@property (nonatomic,strong) UILabel* newsAuthorLabel;
@property (nonatomic,strong) UILabel* newsCommentsLabel;
@property (nonatomic,strong) UIImageView* pictureImageView;
-(void)setContentData:(News*)news;
+(instancetype)newsCellWithTableView:(UITableView*)tableView;
@end


//
//  NewsCell.m
//  M04P20-新闻
//
//  Created by 张泽阳 on 4/26/15.
//  Copyright (c) 2015 张泽阳. All rights reserved.
//

#import "NewsCell.h"
#import "News.h"
#import "Masonry.h"
@implementation NewsCell

/**
 *  懒加载
 */
-(UILabel *)newsCommentsLabel{
    if (!_newsCommentsLabel) {
        _newsCommentsLabel = [[UILabel alloc]init];
    }
    return _newsCommentsLabel;
}
-(UILabel *)newsTitleLabel{
    if (!_newsTitleLabel) {
        _newsTitleLabel = [[UILabel alloc]init];

    }
    return _newsTitleLabel;
}
-(UILabel *)newsAuthorLabel{
    if (!_newsAuthorLabel) {
        _newsAuthorLabel = [[UILabel alloc]init];
        [self.contentView addSubview:_newsAuthorLabel];
    }
    return _newsAuthorLabel;
}
-(UIImageView *)pictureImageView{
    if (!_pictureImageView) {
        _pictureImageView = [[UIImageView alloc]init];
    }
    return _pictureImageView;
}
/**
 *  便利构造器
 */
+(instancetype)newsCellWithTableView:(UITableView *)tableView{
    static NSString* ID = @"news";
    NewsCell* cell = [tableView dequeueReusableCellWithIdentifier:ID];
    if (!cell) {
        cell = [[NewsCell alloc]initWIthTableView:tableView andID:ID];
    }

    [cell setNeedsLayout];
    [cell layoutIfNeeded];
    return cell;
}
/**
 *  init中设置相对固定的数据
 *
 */
-(instancetype)initWIthTableView:(UITableView*)tablview andID:(NSString*)ID{
//    static NSString* ID = @"news";
    self = [super initWithStyle:UITableViewCellStyleDefault reuseIdentifier:ID];//别忘了super init
    [self.contentView addSubview:self.newsTitleLabel];
    [self.contentView addSubview:self.newsAuthorLabel];
    [self.contentView addSubview:self.pictureImageView];
    [self.contentView addSubview:self.newsCommentsLabel];

    self.newsCommentsLabel.textColor = [UIColor grayColor];
    self.newsCommentsLabel.font = [UIFont systemFontOfSize:12];
    [self.newsCommentsLabel setHighlightedTextColor:[UIColor whiteColor]];
    self.newsAuthorLabel.textColor = [UIColor grayColor];
    self.newsAuthorLabel.font = [UIFont systemFontOfSize:12];
    [self.newsAuthorLabel setHighlightedTextColor:[UIColor whiteColor]];

    self.newsTitleLabel.font = [UIFont boldSystemFontOfSize:15];
    self.newsTitleLabel.numberOfLines = 0;

    [self.newsTitleLabel setHighlightedTextColor:[UIColor whiteColor]];
    self.pictureImageView.contentMode = UIViewContentModeScaleAspectFit;

    return self;
}
/**
 *  设置相对动态的数据
 */
-(void)setContentData:(News *)news{
    self.newsTitleLabel.text = news.title;
    self.newsAuthorLabel.text = news.author;
    self.newsCommentsLabel.text = [NSString stringWithFormat:@"评论：%d",news.comments];
    self.pictureImageView.image = [UIImage imageNamed:news.icon];
}
/**
 *  设置布局  记得调用super
 */
-(void)layoutSubviews{
    [super layoutSubviews];
    [self.newsTitleLabel mas_makeConstraints:^(MASConstraintMaker *make){
        make.top.equalTo(self.contentView.mas_top).mas_offset(8);  ///offset???
        make.left.equalTo(self.contentView.mas_left).mas_offset(8);
        make.right.equalTo(self.pictureImageView.mas_left).mas_offset(-8);
    }];

    [self.newsAuthorLabel mas_makeConstraints:^(MASConstraintMaker *make){
        make.left.equalTo(self.newsTitleLabel);
        make.top.greaterThanOrEqualTo(self.newsTitleLabel.mas_bottom).mas_offset(8);
        make.bottom.equalTo(self.contentView.mas_bottom).mas_offset(-8);
    }];

    [self.newsCommentsLabel mas_makeConstraints:^(MASConstraintMaker *make){
        make.top.equalTo(self.newsAuthorLabel.mas_top);
        make.right.equalTo(self.pictureImageView.mas_left).mas_offset(-8);
    }];

    [self.pictureImageView mas_makeConstraints:^(MASConstraintMaker *make){
        make.top.equalTo(self.contentView.mas_top).mas_offset(8);
        make.right.equalTo(self.contentView.mas_right).mas_offset(-8);
        make.bottom.equalTo(self.contentView.mas_bottom).mas_offset(-8);
        make.width.mas_equalTo(120);
    }];
}
/**
 *  单元格被选中/取消选中时的表现
 */
-(void)setSelected:(BOOL)selected animated:(BOOL)animated{
    [super setSelected:selected animated:animated];
//    self.newsTitleLabel.textColor = selected?([UIColor whiteColor]):([UIColor blackColor]);
//    self.newsAuthorLabel.textColor = selected?([UIColor whiteColor]):([UIColor blackColor]);
//    self.newsCommentsLabel.textColor = selected?([UIColor whiteColor]):([UIColor blackColor]);
}
@end

Controller中：

//
//  ViewController.h
//  M04P20-新闻
//
//  Created by 张泽阳 on 4/26/15.
//  Copyright (c) 2015 张泽阳. All rights reserved.
//

#import <UIKit/UIKit.h>

@interface ViewController : UIViewController
@property (nonatomic,strong) NSArray* newses;

@end


//
//  ViewController.m
//  M04P20-新闻
//
//  Created by 张泽阳 on 4/26/15.
//  Copyright (c) 2015 张泽阳. All rights reserved.
//

#import "ViewController.h"
#import "News.h"
#import "NewsCell.h"
#import "NSObject+NSObject_ZZYMODEL.h"
@interface ViewController ()<UITableViewDelegate,UITableViewDataSource>
@property (weak, nonatomic) IBOutlet UITableView *tableView;

@end

@implementation ViewController
-(NSArray *)newses{
    if (!_newses) {
        _newses = [News modelArrayWithFilename:@"news.plist"];
    }
    return _newses;
}
- (void)viewDidLoad {
    [super viewDidLoad];
    self.tableView.estimatedRowHeight = 54;
    self.tableView.rowHeight = UITableViewAutomaticDimension;
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(orientationDidRotate) name:UIApplicationDidChangeStatusBarOrientationNotification object:nil];
}
-(BOOL)prefersStatusBarHidden{
    return YES;
}
-(void)orientationDidRotate{
    [self.tableView reloadData];
}
-(NSInteger)numberOfSectionsInTableView:(UITableView *)tableView{
    return 1;
}

-(NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section{
    return self.newses.count;
}

-(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{
    NewsCell* cell = [NewsCell newsCellWithTableView:tableView];
    [cell setContentData:self.newses[indexPath.row]];


     return cell;

}




@end

参考连接：

http://itony.me/381.html

http://www.mgenware.com/blog/?p=507

http://blog.163.com/china_uv/blog/static/1171372672014111681232340/

http://codingobjc.com/blog/2014/10/15/shi-yong-autolayoutshi-xian-uitableviewde-celldong-tai-bu-ju-he-ke-bian-xing-gao/index.html