iOS网络编程-MBProgressHUD等待指示器

第三方的等待指示器，MBProgressHUD就是第三方提供的等待指示器框架。下面是MBProgressHUD提供的等待指示器样式，它们基本可以分为：未知结束时间和已知结束时间两大类等待指示器，在MBProgressHUD中可以为等待指示器添加标签和详细标签

MBProgressHUD的下载地址是https://github.com/matej/MBProgressHUD，我们将下载的源文件中的MBProgressHUD.h和MBProgressHUD.m拷贝到自己的工程中，MBProgressHUD依赖的框架有：Foundation.framework、UIKit.framework和CoreGraphics.framework，我们需要将这些框架添加到工程中。

我们为应用添加MBProgressHUD等待指示器，修改主视图控制器MasterViewController.m的startRequest方法代码如下，注意加粗部分：

-(void)startRequest{    //初始化MBProgressHUD    MBProgressHUD *hud = [MBProgressHUD showHUDAddedTo:self.view animated:YES];    hud.mode = MBProgressHUDModeCustomView;    hud.labelText = @”Loading”;NSString *strURL = [[NSString alloc]initWithFormat:@”http://iosbook3/mynotes/webservice.php”];NSURL *url = [NSURL URLWithString:[strURL URLEncodedString]];NSString *post;if (action == ACTION_QUERY) {//查询处理post = [NSString stringWithFormat:@"email=%@&type=%@&action=%@",@"<你的iosbook1.com用户邮箱>",@"JSON",@"query"];} else if (action == ACTION_REMOVE) {//删除处理NSIndexPath *indexPath = [self.tableView indexPathForSelectedRow];NSMutableDictionary*  dict = self.listData[indexPath.row];post = [NSString stringWithFormat:@"email=%@&type=%@&action=%@&id=%@",@"<你的iosbook1.com用户邮箱>",@"JSON",@"remove",[dict objectForKey:@"ID"]];}NSData *postData  = [post dataUsingEncoding:NSUTF8StringEncoding];NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url];[request setHTTPMethod:@"POST"];[request setHTTPBody:postData];NSURLConnection *connection = [[NSURLConnection alloc]initWithRequest:request delegate:self];if (connection) {_datas = [NSMutableData new];}}-(void) connection:(NSURLConnection *)connection didFailWithError: (NSError *)error {NSLog(@”%@”,[error localizedDescription]);[MBProgressHUD hideHUDForView:self.view animated:YES];} - (void) connectionDidFinishLoading: (NSURLConnection*) connection {NSLog(@”请求完成…”);NSDictionary* dict = [NSJSONSerialization JSONObjectWithData:_datasoptions:NSJSONReadingAllowFragments error:nil];if (action == ACTION_QUERY) {//查询处理[self reloadView:dict];} else if (action == ACTION_REMOVE) {//删除处理NSString *message = @”操作成功。”;NSNumber *resultCodeObj = [dict objectForKey:@"ResultCode"];if ([resultCodeObj integerValue] < 0) {message = [resultCodeObj errorMessage];}UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:@”提示信息”message:messagedelegate:nilcancelButtonTitle:@”OK”otherButtonTitles: nil];[alertView show];//重新查询action = ACTION_QUERY;[self startRequest];} [MBProgressHUD hideHUDForView:self.view animated:YES];}