把下载的文件存到指定的文件夹中

来源：互联网发布：网络与诸葛亮什么意思编辑：程序博客网时间：2024/04/29 15:26

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];
}