下载器

//
//  ViewController.m
//  NSConnection-0805
//
//  Created by apple on 14-8-5.
//  Copyright (c) 2014年 apple. All rights reserved.
//

#import "ViewController.h"

@interface ViewController ()<NSURLConnectionDataDelegate>
{
    NSMutableData *_totalData;
    long long _totalDataLenth;
    NSFileHandle *_fileHandle;
    NSURL *_url;
    NSURLConnection *_connection;
}
@property(nonatomic,strong)UIProgressView *progressView;
@property(nonatomic,strong)UITextField *urlTextField;
@end

@implementation ViewController
            
- (void)viewDidLoad {
    [super viewDidLoad];
    _totalData=[[NSMutableData alloc]init];
    self.view.backgroundColor=[UIColor greenColor];
    //进度条的创建
    _progressView=[[UIProgressView alloc]initWithProgressViewStyle:UIProgressViewStyleDefault];
    _progressView.frame=CGRectMake(70, 150, 150, 20);
    _progressView.progressTintColor=[UIColor blueColor];
    [self.view addSubview:_progressView];
    
    //URL输入栏
    _urlTextField=[[UITextField alloc]initWithFrame:CGRectMake(40, 200, 200, 30)];
    _urlTextField.backgroundColor=[UIColor whiteColor];
    [self.view addSubview:_urlTextField];
    
    //创建下载按钮
    UIButton *downLoad=[UIButton buttonWithType:UIButtonTypeCustom];
    downLoad.frame=CGRectMake(100, 300, 120, 40);
    [downLoad setTitle:@"开始下载" forState:UIControlStateNormal];
    [downLoad addTarget:self action:@selector(down) forControlEvents:UIControlEventTouchUpInside];
    [self.view addSubview:downLoad];
    
    
    NSFileManager *fileManager=[NSFileManager defaultManager];
    [fileManager createFileAtPath:@"/Users/apple/Desktop/test1.mp4" contents:nil attributes:nil];
    _fileHandle=[NSFileHandle fileHandleForWritingAtPath:@"/Users/apple/Desktop/test1.mp4"] ;
//    _url=[NSURL URLWithString:@"http://class.room/hdmv.mp4"];

//    NSURLRequest *request=[NSURLRequest requestWithURL:_url];
//    NSURLConnection *connection=[NSURLConnection connectionWithRequest:request delegate:self];
//    [connection start];
//    _connection=[[NSURLConnection alloc]initWithRequest:request delegate:self];
    
}

//按钮方法
- (void)down
{
    
    [_fileHandle truncateFileAtOffset:0];
    _url=[NSURL URLWithString:_urlTextField.text];
    NSURLRequest *request=[NSURLRequest requestWithURL:_url];
    //    NSURLConnection *connection=[NSURLConnection connectionWithRequest:request delegate:self];
    //    [connection start];
    _connection=[[NSURLConnection alloc]initWithRequest:request delegate:self];
    //开始下载
    [_connection start];
//    [_connection cancel];
}

//连接失败响应方法
- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error
{
    NSLog(@"connection fail %@",error);
}

- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response
{
    NSLog(@"Response%@",response);
    _totalDataLenth=[response expectedContentLength];
}

- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data
{
    NSLog(@"接收数据");
//    [_totalData appendData:data];
    [_fileHandle writeData:data];
//    NSLog(@"==%d",[_totalData length]);
    NSLog(@"data %f",(float)[_fileHandle offsetInFile]/_totalDataLenth);
    _progressView.progress=(float)[_fileHandle offsetInFile]/_totalDataLenth;
}

//连接完成
- (void)connectionDidFinishLoading:(NSURLConnection *)connection
{
    NSLog(@"connection finished");
    [_fileHandle closeFile];
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

@end