开源中国iOS客户端学习——MBProgressHUD特效

在开源中国iOS客户端中也用到了MBProgressHUD这个特效，主要作用为应用显示一个过渡的作用，常用于打开一个联网页面加载过程，防止出现假死现象，如果网速慢则告诉用户已经在很努力很努力的加载中。

GitHub上下载地址：https://github.com/jdg/MBProgressHUD

源码中也自带了一个Demo,显示13中动画效果，可以根据需要选取其中特效加以使用，使用方法基本一样；使用的时候只加把MBProgressHUD.h和MBProgressHUD.m拖入工程中，在使用的文件中加上#import"MBProgressHUD.h"

在开源中国iOS客户端中只用到一种特效,当我们选取一条资讯查看详细信息时：

   

我们在跳转到实现的代码部分，在NewsDetail.m的clickFavorite和viewDidLoad方法中

 - (void)clickFavorite:(id)sender
 {
     UIBarButtonItem * btn = (UIBarButtonItem *)sender;
     BOOL isFav = [btn.title isEqualToString:@"收藏此文"];

     MBProgressHUD *hud = [[MBProgressHUD alloc] initWithView:self.view];
     [Tool showHUD:isFav ? @"正在添加收藏":@"正在删除收藏" andView:self.view andHUD:hud];
     [[AFOSCClient sharedClient]getPath:isFav ? api_favorite_add : api_favorite_delete
                             parameters:[NSDictionary dictionaryWithObjectsAndKeys:
                                         [NSString stringWithFormat:@"%d", [Config Instance].getUID],@"uid",
                                         [NSString stringWithFormat:@"%d", newsID],@"objid",
                                         @"4",@"type", nil] success:^(AFHTTPRequestOperation *operation, id responseObject) {

                                 [hud hide:YES];
                                 [Tool getOSCNotice2:operation.responseString];

                                 ApiError *error = [Tool getApiError2:operation.responseString];
                                 if (error == nil) {
                                     [Tool ToastNotification:operation.responseString andView:self.view andLoading:NO andIsBottom:NO];
                                     return ;
                                 }
                                 switch (error.errorCode)
                                 {
                                     case 1:
                                     {
                                         btnFavorite.title = isFav ? @"取消收藏" : @"收藏此文";
                                         self.singleNews.favorite = !self.singleNews.favorite;
                                     }
                                         break;
                                     case 0:
                                     case -2:
                                     case -1:
                                     {
                                         [Tool ToastNotification:[NSString stringWithFormat:@"错误 %@",error.errorMessage] andView:self.view andLoading:NO andIsBottom:NO];
                                     }
                                         break;
                                 }


     } failure:^(AFHTTPRequestOperation *operation, NSError *error) {
         [hud hide:YES];
         [Tool ToastNotification:@"添加收藏失败" andView:self.view andLoading:NO andIsBottom:NO];
     }];
 }

 - (void)viewDidLoad
 {
     [super viewDidLoad];
     self.tabBarItem.title = @"资讯详情";
     self.tabBarItem.image = [UIImage imageNamed:@"detail"];
     //WebView的背景颜色去除
     [Tool clearWebViewBackground:self.webView];

     self.singleNews = [[SingleNews alloc] init];
     self.navigationController.title = @"资讯详情";
     self.webView.delegate = self;
     [self.webView loadHTMLString:@"" baseURL:nil];

     if ([Config Instance].isNetworkRunning)
     {
         MBProgressHUD *hud = [[MBProgressHUD alloc] initWithView:self.view];
         [Tool showHUD:@"正在加载" andView:self.view andHUD:hud];

         NSString *url = [NSString stringWithFormat:@"%@?id=%d",api_news_detail, newsID];
         [[AFOSCClient sharedClient] getPath:url parameters:nil success:^(AFHTTPRequestOperation *operation, id responseObject) {

             [Tool getOSCNotice2:operation.responseString];
             [hud hide:YES];

             self.singleNews = [Tool readStrNewsDetail:operation.responseString];
             if (self.singleNews == nil) {
                 [Tool ToastNotification:@"加载失败" andView:self.view andLoading:NO andIsBottom:NO];
                 return;
             }
             [self loadData:self.singleNews];

             //如果有网络 则缓存它
             if ([Config Instance].isNetworkRunning)
             {
                 [Tool saveCache:1 andID:self.singleNews._id andString:operation.responseString];
             }

         } failure:^(AFHTTPRequestOperation *operation, NSError *error) {

             [hud hide:YES];
             if ([Config Instance].isNetworkRunning) {
                 [Tool ToastNotification:@"错误 网络无连接" andView:self.view andLoading:NO andIsBottom:NO];
             }

         }];
     }
     else
     {
         NSString *value = [Tool getCache:1 andID:newsID];
         if (value) {
             self.singleNews = [Tool readStrNewsDetail:value];
             [self loadData:self.singleNews];
         }
         else {
             [Tool ToastNotification:@"错误 网络无连接" andView:self.view andLoading:NO andIsBottom:NO];
         }
     }
 }

分析viewDidLoad方法，

首先是判断网络是否连通状态，如果是

定义在当前的view中定义一个MBProgressHUD对象，进行初始化

[ToolshowHUD:@"正在加载" andView:self.viewandHUD:hud];是在Tool类里面进行的一次封装，设置MBProgressHUD的显示信息

 + (void)showHUD:(NSString *)text andView:(UIView *)view andHUD:(MBProgressHUD *)hud
 {
     [view addSubview:hud];
     hud.labelText = text;//显示提示
     hud.dimBackground = YES;//使背景成黑灰色，让MBProgressHUD成高亮显示
     hud.square = YES;//设置显示框的高度和宽度一样
     [hud show:YES];
 }

然后在用到AFNetWork类库的getPath:parameters:success:failure:方法，嵌套在block块中判断请求的url是否成功，在执行[Tool getOSCNotice2:operation.responseString];这个方法也是封装在Tool类中，封装的是TBXML解析器，如果解析成功立即设置MBProgressHUD隐藏属性[hud hide:YES];如果请求的url不成功直接设置MBProgressHUD隐藏属性[hud hide:YES]，再用GCDiscreetNotificationView进行通知“错误 网络无连接”;