学习制作iOS程序第九天：新闻资讯列表（27）

二十七：新闻资讯列表页

有了首页二手房的经验，新闻资讯列表显得简单的多。先看看效果吧

1、创建实体文件NewsListModel

#import <Foundation/Foundation.h>

@interface NewsListModel : NSObject

@property(nonatomic,assign) NSInteger NewsID;
@property(nonatomic,copy) NSString *NewsTitle;
@property(nonatomic,copy) NSString *NewsDesc;
@property(nonatomic,copy) NSString *NewsDate;
@property(nonatomic,copy) NSString *NewsClassName;
@property(nonatomic,copy) NSString *NewsImage;

-(instancetype)initWithDict:(NSDictionary *)dict;

@end

#import "NewsListModel.h"

@implementation NewsListModel

-(instancetype)initWithDict:(NSDictionary *)dict
{
    if (self=[super init]) {
        _NewsID = [[dict objectForKey:@"NewsID"] integerValue];
        _NewsTitle = [dict objectForKey:@"NewsTitle"];
        _NewsDesc = [dict objectForKey:@"NewsDesc"];
        _NewsDate = [dict objectForKey:@"NewsDate"];
        _NewsClassName = [dict objectForKey:@"NewsClassName"];
        _NewsImage = [dict objectForKey:@"NewsImage"];
    }
    return self;
}

@end

2、创建单元格原型文件NewsListCell

#import <UIKit/UIKit.h>
#import "NewsListModel.h"

@interface NewsListCell : UITableViewCell

@property(nonatomic,strong) UIImageView *NewsImage;
@property(nonatomic,strong) UILabel *NewsTitle;
@property(nonatomic,strong) UILabel *NewsClassName;
@property(nonatomic,strong) UILabel *NewsDate;
@property(nonatomic,strong) UILabel *NewsDesc;

@property(nonatomic,strong) NewsListModel *news;

+(instancetype)cellWithTableView:(UITableView *)tableView;

@end

+(instancetype)cellWithTableView:(UITableView *)tableView
{
    static NSString *cellstr = @"newslistcell";
    NewsListCell *cell=[tableView dequeueReusableCellWithIdentifier:cellstr];
    if (cell==nil) {
        cell=[[NewsListCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:cellstr];
    }
    return cell;
}

#pragma mark - 重写初始化方法
-(id)initWithStyle:(UITableViewCellStyle)style reuseIdentifier:(NSString *)reuseIdentifier
{
    if(self=[super initWithStyle:style reuseIdentifier:reuseIdentifier])
    {
        _NewsTitle=[[UILabel alloc]initWithFrame:CGRectMake(10, 10, SCREEN_WIDTH-20, 21)];
        _NewsTitle.font=[UIFont boldSystemFontOfSize:15];
        [self.contentView addSubview:_NewsTitle];
        
        _NewsImage = [[UIImageView alloc] initWithFrame:CGRectMake(10, 37 ,100, 75)];
        [self.contentView addSubview:_NewsImage];
        
        _NewsDesc = [[UILabel alloc] initWithFrame:CGRectMake(120, 37, SCREEN_WIDTH-130, 60)];
        _NewsDesc.numberOfLines=3;
        _NewsDesc.font=[UIFont systemFontOfSize:14];
        _NewsDesc.textColor = [UIColor grayColor];
        [self.contentView addSubview:_NewsDesc];
        
        _NewsDate = [[UILabel alloc] initWithFrame:CGRectMake(120, 97, SCREEN_WIDTH-20, 18)];
        _NewsDate.font=[UIFont systemFontOfSize:12];
        _NewsDate.textColor=[UIColor grayColor];
        [self.contentView addSubview:_NewsDate];
        
        _NewsClassName =[[UILabel alloc] initWithFrame:CGRectMake(SCREEN_WIDTH-65, 98, 55, 17)];
        _NewsClassName.font=[UIFont systemFontOfSize:10];
        _NewsClassName.textColor = COLOR(15, 111, 172, 1);
        _NewsClassName.layer.borderColor = COLOR(15, 111, 172, 1).CGColor;
        _NewsClassName.layer.borderWidth = 0.5f;
        _NewsClassName.textAlignment=NSTextAlignmentCenter;
        [self.contentView addSubview:_NewsClassName];
    }
    return self;
}

#pragma mark - 重构函数
-(void)setNews:(NewsListModel *)modnews
{
    _news = modnews;
    
    _NewsTitle.text = modnews.NewsTitle;
    _NewsDate.text = modnews.NewsDate;
    _NewsClassName.text = modnews.NewsClassName;
    //_NewsDesc.text = modnews.NewsDesc;
    [_NewsImage sd_setImageWithURL:[NSURL URLWithString:modnews.NewsImage] placeholderImage:[UIImage imageNamed:@"defaultimage"]];
    
    //测试代码设置行高
    if ([modnews.NewsDesc isEqualToString:@""] == NO)
    {
        NSMutableAttributedString *attributedstring =[[NSMutableAttributedString alloc] initWithString:modnews.NewsDesc];
        NSMutableParagraphStyle *paragraphstyle = [[NSMutableParagraphStyle alloc] init];
        [paragraphstyle setLineSpacing:2.8f];
        [attributedstring addAttribute:NSParagraphStyleAttributeName value:paragraphstyle range:NSMakeRange(0, [modnews.NewsDesc length])];
        [_NewsDesc setAttributedText:attributedstring];
    }else{
        _NewsDesc.text = @"";
    }
    
}

3、UrlDefine.h文件定义一下请求的url地址

#define BASE_URL_NEWS_LIST @"/news.ashx?action=list"

4、HttpHelper中添加获取新闻资讯列表的方法

#pragma mark - 获取新闻资讯列表
-(void)GetNewsListWithHUD:(BOOL)ishud andDict:(NSMutableDictionary *)dict;

#pragma mark - 获取新闻资讯列表
-(void)GetNewsListWithHUD:(BOOL)ishud andDict:(NSMutableDictionary *)dict
{
    [self postDataWithURLString:[NSString stringWithFormat:@"%@%@",BASE_URL,BASE_URL_NEWS_LIST] andParameters:dict andHUD:ishud andFlag:@"News_List"];
}

5、.h头文件定义变量

#import <UIKit/UIKit.h>

@interface RDNewsListViewController : UIViewController

@property(nonatomic,strong) UITableView *tableView;

@end

6、.m文件定义变量

@interface RDNewsListViewController ()<UITableViewDataSource,UITableViewDelegate,HttpHelperDelegate>
{
    HttpHelper *helper;
    NSMutableArray *arrNewsList;
    NSMutableDictionary *searchdict;
    
    NSUInteger pageindex;
    NSUInteger pagesize;
}
@end

7、变量初始化

    //初始化
    self.title=@"新闻资讯";
    arrNewsList = [NSMutableArray array];
    helper=[HttpHelper httpHelper];
    helper.delegate=self;
    searchdict = [NSMutableDictionary dictionary];
    pagesize=15;
    pageindex=1;
    
    //提交请求
    [searchdict setObject:[NSString stringWithFormat:@"%lu",pageindex] forKey:@"pageindex"];
    [searchdict setObject:[NSString stringWithFormat:@"%lu",pagesize] forKey:@"pagesize"];  //此行也可以不要，后台默认15条数据每页
    [helper GetNewsListWithHUD:YES andDict:searchdict];

8、页面初始化tableview

    //初始化tableviwe
    _tableView = [[UITableView alloc] initWithFrame:CGRectMake(0, 0, SCREEN_WIDTH, SCREEN_HEIGHT) style:UITableViewStylePlain];
    _tableView.rowHeight = BASE_HEIGHT_NEWSLISTCELL;
    _tableView.dataSource=self;
    _tableView.delegate=self;
    if ([_tableView respondsToSelector:@selector(setSeparatorInset:)]) { [_tableView setSeparatorInset:UIEdgeInsetsZero];}
    if ([_tableView respondsToSelector:@selector(setLayoutMargins:)]) { [_tableView setLayoutMargins:UIEdgeInsetsZero];}
    [self.view addSubview:_tableView];

9、实现httpHelper的代理方法

#pragma mark - 实现httphelper代理
-(void)HttpExecuteFailure:(AFHTTPRequestOperation *)operation andError:(NSError *)error andFlag:(NSString *)flag
{
    NSLog(@"ERROR=%@",error);
    [self.view makeToast:@"服务器错误，请稍候再试。" duration:3.0 position:CSToastPositionCenter];
}
-(void)HttpExecuteSuccess:(AFHTTPRequestOperation *)operation andResponseObject:(id)responseObject andFlag:(NSString *)flag
{
    //NSLog(@"SUCCESS=%@",responseObject);
    NSDictionary *dict = (NSDictionary *)responseObject;
    if (1 == [[dict objectForKey:@"success"] integerValue]) {
        [self initDataWithDict:dict];
    }else{
        [self.view makeToast:[dict objectForKey:@"msg"] duration:3.0 position:CSToastPositionCenter];
    }
}
-(void)initDataWithDict:(NSDictionary *)dict
{
    //如果获取的是第一页的数据，表示刚进入该view或者刷新该view
    if (pageindex==1) { [arrNewsList removeAllObjects]; }
    
    NSArray *arrnews = [dict objectForKey:@"NewsList"];
    
    for (NSDictionary *dic in arrnews) {
        NewsListModel *modnews = [[NewsListModel alloc]initWithDict:dic];
        [arrNewsList addObject:modnews];
    }
    [_tableView reloadData];
}

10、实现tableview的代理方法

#pragma mark - 实现tableview代理方法
-(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    NewsListCell *cell=[NewsListCell cellWithTableView:tableView];
    NewsListModel *modnews = arrNewsList[indexPath.row];
    cell.news =modnews;
    return cell;
}
-(NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    return arrNewsList.count;
}
-(void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
    [tableView deselectRowAtIndexPath:indexPath animated:NO];

    NewsListModel *modnews = arrNewsList[indexPath.row];
    RDNewsDetailViewController *detail = [[RDNewsDetailViewController alloc]init];
    detail.NewsID=modnews.NewsID;
    self.navigationItem.backBarButtonItem =[[UIBarButtonItem alloc] initWithTitle:@"返回" style:UIBarButtonItemStyleDone target:nil action:nil];
    [self.navigationController pushViewController:detail animated:YES];
}
-(void)tableView:(UITableView *)tableView willDisplayCell:(UITableViewCell *)cell forRowAtIndexPath:(NSIndexPath *)indexPath
{
    if ([cell respondsToSelector:@selector(setSeparatorInset:)]) { [cell setSeparatorInset:UIEdgeInsetsZero];}
    if ([cell respondsToSelector:@selector(setLayoutMargins:)]) { [cell setLayoutMargins:UIEdgeInsetsZero];}
}

#pragma mark - 隐藏hud和网络
-(void)viewWillDisappear:(BOOL)animated
{
    [[HttpHelper httpHelper] CancelAllRequest];
    [ToolsHelper CloseHUD];
    [super viewWillDisappear:animated];
}