IOS文件下载

      NSString *urlAsString = @"http://files.cnblogs.com/zhuqil/UIWebViewDemo.zip";
              NSURL    *url = [NSURL URLWithString:urlAsString];
              NSURLRequest *request = [NSURLRequest requestWithURL:url];
              NSError *error = nil;
              NSData   *data = http://www.cnblogs.com/zhwl/archive/2012/07/13/[NSURLConnection sendSynchronousRequest:request 
                                                     returningResponse:nil
                                                                 error:&error];
             /* 下载的数据 */
             if (data != nil){
                 NSLog(@"下载成功");
                 if ([data writeToFile:@"UIWebViewDemo.zip" atomically:YES]) {
                     NSLog(@"保存成功.");
                  }
                 else
                  {
                     NSLog(@"保存失败.");
                  }
              } else {
                 NSLog(@"%@", error);
              }
  
 

  
 
 

2.异步下载

      DownLoadingViewController.h
      // DownLoadingViewController.h 
      // DownLoading 
      // 
      // Created by skylin zhu on 11-7-30. 
      // Copyright 2011年 mysoft. All rights reserved. 
      // 
      #import 
      @interface DownLoadingViewController : UIViewController {
          NSURLConnection *connection;
          NSMutableData *connectionData;
      }
      @property (nonatomic,retain) NSURLConnection *connection;
      @property (nonatomic,retain) NSMutableData *connectionData;
      @end
      DownLoadingViewController.m
      // DownLoadingViewController.m 
      // DownLoading 
      // 
      // Created by skylin zhu on 11-7-30. 
      // Copyright 2011年 mysoft. All rights reserved. 
      // 
      #import "DownLoadingViewController.h" 
      @implementation DownLoadingViewController
      @synthesize connection,connectionData;
      - (void)dealloc
      {
          [super dealloc];
      }
      - (void)didReceiveMemoryWarning
      {
         // Releases the view if it doesn't have a superview. 
          [super didReceiveMemoryWarning];
         // Release any cached data, images, etc that aren't in use. 
      }
      #pragma mark - View lifecycle 
      // Implement viewDidLoad to do additional setup after loading the view, typically from a nib. 
      - (void)viewDidLoad
      {
          [super viewDidLoad];
         //文件地址 
          NSString *urlAsString = @"http://files.cnblogs.com/zhuqil/UIWebViewDemo.zip";
          NSURL    *url = [NSURL URLWithString:urlAsString];
          NSURLRequest *request = [NSURLRequest requestWithURL:url];
          NSMutableData *data = http://www.cnblogs.com/zhwl/archive/2012/07/13/[[NSMutableData alloc] init]; 
          self.connectionData = http://www.cnblogs.com/zhwl/archive/2012/07/13/data; 
          [data release];
          NSURLConnection *newConnection = [[NSURLConnection alloc]
                                            initWithRequest:request
                                            delegate:self
                                            startImmediately:YES];
          self.connection = newConnection;
          [newConnection release];
         if (self.connection != nil){
            NSLog(@"Successfully created the connection");
          } else {
             NSLog(@"Could not create the connection");
          }
      }
      - (void) connection:(NSURLConnection *)connection
                  didFailWithError:(NSError *)error{
         NSLog(@"An error happened");
         NSLog(@"%@", error);
      }
      - (void) connection:(NSURLConnection *)connection
                    didReceiveData:(NSData *)data{
         NSLog(@"Received data");
          [self.connectionData appendData:data];
      }
      - (void) connectionDidFinishLoading
      :(NSURLConnection *)connection{
         /* 下载的数据 */
             NSLog(@"下载成功");
             if ([self.connectionData writeToFile:@"UIWebViewDemo.zip" atomically:YES]) {
                 NSLog(@"保存成功.");
              }
             else
              {
                 NSLog(@"保存失败.");
              }
         /* do something with the data here */
      }
      - (void) connection:(NSURLConnection *)connection
                didReceiveResponse:(NSURLResponse *)response{
          [self.connectionData setLength:0];
      }
      - (void) viewDidUnload{
          [super viewDidUnload];
          [self.connection cancel];
          self.connection = nil;
          self.connectionData = http://www.cnblogs.com/zhwl/archive/2012/07/13/nil; 
      }
      @end
  
 

  
 
 

文章来源: zzzili.blog.csdn.net，作者：清雨小竹，版权归原作者所有，如需转载，请联系作者。

原文链接：zzzili.blog.csdn.net/article/details/8424164