UIDocumentPickerViewController使用

场景：从服务端下载文件到iPhone文件夹或者从iPhone本地文件夹选择文件上传服务端

UIDocumentPickerViewController有四种模式：

typedef NS_ENUM(NSUInteger, UIDocumentPickerMode) {
    UIDocumentPickerModeImport,
    UIDocumentPickerModeOpen,
    UIDocumentPickerModeExportToService,
    UIDocumentPickerModeMoveToService
} API_DEPRECATED("Use appropriate initializers instead",ios(8.0,14.0)) API_UNAVAILABLE(tvos);

• UIDocumentPickerModeImport：用户选择一个外部文档，文档选择器拷贝该文档到应用沙盒，不会修改源文档。
• UIDocumentPickerModeOpen：打开一个外部文档，用户可以修改该文档。
• UIDocumentPickerModeExportToService：文档选择器拷贝文档到一个外部路径，不会修改源文档。
• UIDocumentPickerModeMoveToService：拷贝文档到外部路径，同时可以修改该拷贝。

1、下载文件存储到iPhone 本地文件夹

-(void)requestImageUrl:(NSString *)imageUrl {
    [[DDLoading shared] show];
  
//     // 下载图片之前先检查本地是否已经有图片
//     UIImage * image = [self loadLocalImage:imageUrl];
//     NSData *imageData = UIImagePNGRepresentation(image);
//     //如果图片存在直接跳出；不用下载了
//     if (imageData) {
//       self.successBlock(imageData);
//       return;
//     }
   
   // 没有本地图片
   // 创建URL对象
//    NSURL *url = [NSURL URLWithString:[imageUrl stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]];
      NSURL *url = [NSURL URLWithString:[imageUrl stringByAddingPercentEncodingWithAllowedCharacters:[NSCharacterSet URLQueryAllowedCharacterSet]]];
   // 创建request对象
   NSURLRequest *request = [NSURLRequest requestWithURL:url];
   
   // 使用URLSession来进行网络请求
   // 创建会话配置对象
   NSURLSessionConfiguration *sessionConfiguration = [NSURLSessionConfiguration defaultSessionConfiguration];
   // 创建会话对象
   NSURLSession *session = [NSURLSession sessionWithConfiguration:sessionConfiguration];
   // 创建会话任务对象
   NSURLSessionTask *task = [session dataTaskWithRequest:request completionHandler:^(NSData * _Nullable data, NSURLResponse * _Nullable response, NSError * _Nullable error) {
        if (data) {
            // 将下载的数据传出去，进行UI更新
            DebugLog(@"文件下载成功~~~~~~%@",data);
                // 下载完成，将图片保存到本地
                [data writeToFile:[self imageFilePath:imageUrl] atomically:YES];
        
                dispatch_async(dispatch_get_main_queue(), ^{
                     //遮罩关闭
                    NSString * urlPath =[self imageFilePath:imageUrl] ;
                    UIDocumentPickerViewController *documentPicker = [[UIDocumentPickerViewController alloc] initWithURL:[NSURL URLWithString:[NSString stringWithFormat:@"file://%@",urlPath]] inMode:UIDocumentPickerModeExportToService];
                       documentPicker.delegate = self;
                       documentPicker.modalPresentationStyle = UIModalPresentationFormSheet;
                       [Singleton.rootViewController presentViewController:documentPicker animated:YES completion:nil];
                });
          
            
        }
        if (error) {
            DebugLog(@"文件下载失败~~~~~~%@",error);
             dispatch_async(dispatch_get_main_queue(), ^{
             //遮罩关闭
             });
             self.jsapiCallback(@{@"result":@"0",@"errorMsg":@"文件下载失败"});
// 51 //
        }
    }];

   // 创建的task都是挂起状态，需要resume才能执行
   [task resume];
}
- (void)documentPicker:(UIDocumentPickerViewController *)controller didPickDocumentsAtURLs:(NSArray <NSURL *>*)urls {
    DebugLog(@"*************************存储成功");
    DebugLog(@"*************************%@",urls);
    self.jsapiCallback(@{@"result":@"1"});
}

// called if the user dismisses the document picker without selecting a document (using the Cancel button)
- (void)documentPickerWasCancelled:(UIDocumentPickerViewController *)controller{
   DebugLog(@"*************************存储失败");
    self.jsapiCallback(@{@"result":@"0",@"errorMsg":@"用户取消操作"});
}

- (void)documentPicker:(UIDocumentPickerViewController *)controller didPickDocumentAtURL:(NSURL *)url{
   DebugLog(@"*************************");
}
//
- (NSString *)imageFilePath:(NSString *)imageUrl {
    // 1、获取caches文件夹路径
    NSString * cachesPath = [NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES) lastObject];
    
    // 2、创建DownloadImages文件夹
    NSString * downloadImagesPath = [cachesPath stringByAppendingPathComponent:@"DownloadImages"];

    // 3、创建文件管理器对象
    NSFileManager * fileManager = [NSFileManager defaultManager];
    
    // 4、判断文件夹是否存在
    if (![fileManager fileExistsAtPath:downloadImagesPath])
    {
        [fileManager createDirectoryAtPath:downloadImagesPath withIntermediateDirectories:YES attributes:nil error:nil];
    }
    
    // 5、拼接图片在沙盒中的路径
    /*
      因为每一个图片URL对应的是一张图片，而且URL中包含了文件的名称，所以可以用图片的URL来唯一表示图片的名称
      因为图像URL中有"/"，"/"表示的是下级目录的意思，要在存入前替换掉，所以用"_"代替
    */
    NSArray *imageArr = [imageUrl componentsSeparatedByString:@"/"];
    NSString * imageName = [imageArr lastObject];
    NSString * imageFilePath = [downloadImagesPath stringByAppendingPathComponent:imageName];

    // 6、返回文件路径
    return imageFilePath;
}

2、选择iPhone本地文件送给服务端

- (IBAction)shareAction:(id)sender {
    NSArray *types = @[@"public.content"];可选文件类型 types需要传入一个uniform type identifiers (UTIs)数组。关于UTIs的官方文档
    UIDocumentPickerViewController *documentPicker = [[UIDocumentPickerViewController alloc] initWithDocumentTypes:types inMode:UIDocumentPickerModeOpen];
    documentPicker.delegate = self;
    documentPicker.modalPresentationStyle = UIModalPresentationPageSheet;
    [self presentViewController:documentPicker animated:YES completion:nil];
    
}

- (void)documentPicker:(UIDocumentPickerViewController *)controller didPickDocumentAtURL:(NSURL *)url {
    BOOL canAccessingResource = [url startAccessingSecurityScopedResource];
    if(canAccessingResource) {
        NSFileCoordinator *fileCoordinator = [[NSFileCoordinator alloc] init];
        NSError *error;
        [fileCoordinator coordinateReadingItemAtURL:url options:0 error:&error byAccessor:^(NSURL *newURL) {
            NSData *fileData = [NSData dataWithContentsOfURL:newURL];
            NSArray *arr = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
            NSString *documentPath = [arr lastObject];
            NSString *desFileName = [documentPath stringByAppendingPathComponent:@"file"];
            [fileData writeToFile:desFileName atomically:YES];
            NSLog(@"point_test_log%@",desFileName);
            [self dismissViewControllerAnimated:YES completion:NULL];
        }];
        if (error) {
            // error handing
        }
    } else {
        // startAccessingSecurityScopedResource fail
    }
    [url stopAccessingSecurityScopedResource];
}