把下载的文件存到指定的文件夹中

在.h 文件中 实现NSURLConnectionDataDelegate协议

@property (nonatomic, assign) IBOutlet UIProgressView *progressView;

- (IBAction)download;

{

// 文件的总长度

int _totalLength;

}

@property (nonatomic, retain) NSMutableData *data;

.m 文件中

- (void)dealloc {

[_data release];

[super dealloc];

}

- (void)viewDidUnload {

[super viewDidUnload];

self.data = nil;

}

- (void)viewDidLoad

{

[super viewDidLoad];

// Do any additional setup after loading the view, typically from a nib.

}

- (void)download {

self.data = [NSMutableData data];

NSURL *url = [NSURL URLWithString:@"http://192.168.1.106:8080/MJServer/movie.avi"];

NSURLRequest *reuqest = [NSURLRequest requestWithURL:url];

[[NSURLConnection connectionWithRequest:reuqest delegate:self] start];

}

#pragma mark - 代理方法

- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data {

[self.data appendData:data];

// 设置下载进度

self.progressView.progress = (float)self.data.length / (float)_totalLength;

}

#pragma mark 服务器有相应就会调用这个方法

- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response {

NSHTTPURLResponse *rep = (NSHTTPURLResponse *)response;

_totalLength = [[[rep allHeaderFields] objectForKey:@"Content-Length"] intValue];

}

//下载完成后放到指定的文件夹中

- (void)connectionDidFinishLoading:(NSURLConnection *)connection {

NSString *cacheDir = [NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES) lastObject];

NSString *dir = [cacheDir stringByAppendingPathComponent:@"movie"];

NSFileManager *mgr = [NSFileManager defaultManager];

// 是否为文件夹

BOOL isDir;

// 是否存在

BOOL exist = [mgr fileExistsAtPath:dir isDirectory:&isDir];

if (!exist) {

// 创建一个新的文件夹

[mgr createDirectoryAtPath:dir withIntermediateDirectories:YES attributes:nil error:nil];

}

NSString *path = [dir stringByAppendingPathComponent:@"mj.avi"];

// 将文件数据写入Library/Caches文件夹下

[self.data writeToFile:path atomically:YES];

}