ios開發網路學習十：利用檔案控制代碼實現大檔案下載

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#import "ViewController.h"@interface ViewController ()<NSURLSessionDataDelegate>@property (weak, nonatomic) IBOutlet UIProgressView *proessView;/** 接受響應體資訊 */@property (nonatomic, strong) NSFileHandle *handle;@property (nonatomic, assign) NSInteger totalSize;@property (nonatomic, assign) NSInteger currentSize;@property (nonatomic, strong) NSString *fullPath;@end@implementation ViewController-(void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event{    //1.url    NSURL *url = [NSURL URLWithString:@"http://120.25.226.186:32812/resources/videos/minion_02.mp4"];        //2.建立請求對象    NSURLRequest *request = [NSURLRequest requestWithURL:url];        //3.建立會話對象,設定代理    /*     第一個參數:配置資訊 [NSURLSessionConfiguration defaultSessionConfiguration]     第二個參數:代理     第三個參數:設定代理方法在哪個線程中調用     */    NSURLSession *session = [NSURLSession sessionWithConfiguration:[NSURLSessionConfiguration defaultSessionConfiguration] delegate:self delegateQueue:[NSOperationQueue mainQueue]];        //4.建立Task    NSURLSessionDataTask *dataTask = [session dataTaskWithRequest:request];        //5.執行Task    [dataTask resume];}#pragma mark ----------------------#pragma mark NSURLSessionDataDelegate/** *  1.接收到伺服器的響應 它預設會取消該請求 * *  @param session           會話對象 *  @param dataTask          請求任務 *  @param response          回應標頭資訊 *  @param completionHandler 回調 傳給系統 */-(void)URLSession:(NSURLSession *)session dataTask:(NSURLSessionDataTask *)dataTask didReceiveResponse:(NSURLResponse *)response completionHandler:(void (^)(NSURLSessionResponseDisposition))completionHandler{    //獲得檔案的總大小    self.totalSize = response.expectedContentLength;        //獲得檔案全路徑    self.fullPath = [[NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES) lastObject] stringByAppendingPathComponent:response.suggestedFilename];        //建立空的檔案    [[NSFileManager defaultManager]createFileAtPath:self.fullPath contents:nil attributes:nil];        //建立檔案控制代碼    self.handle = [NSFileHandle fileHandleForWritingAtPath:self.fullPath];        [self.handle seekToEndOfFile];    /*     NSURLSessionResponseCancel = 0,取消 預設     NSURLSessionResponseAllow = 1, 接收     NSURLSessionResponseBecomeDownload = 2, 變成下載任務     NSURLSessionResponseBecomeStream        變成流     */    completionHandler(NSURLSessionResponseAllow);}/** *  接收到伺服器返回的資料 調用多次 * *  @param session           會話對象 *  @param dataTask          請求任務 *  @param data              本次下載的資料 */-(void)URLSession:(NSURLSession *)session dataTask:(NSURLSessionDataTask *)dataTask didReceiveData:(NSData *)data{        //寫入資料到檔案    [self.handle writeData:data];        //計算檔案的下載進度    self.currentSize += data.length;    NSLog(@"%f",1.0 * self.currentSize / self.totalSize);        self.proessView.progress = 1.0 * self.currentSize / self.totalSize;}/** *  請求結束或者是失敗的時候調用 * *  @param session           會話對象 *  @param dataTask          請求任務 *  @param error             錯誤資訊 */-(void)URLSession:(NSURLSession *)session task:(NSURLSessionTask *)task didCompleteWithError:(NSError *)error{    NSLog(@"%@",self.fullPath);        //關閉檔案控制代碼    [self.handle closeFile];    self.handle = nil;}@end

 

ios開發網路學習十：利用檔案控制代碼實現大檔案下載