[iOS]从系统“文件”APP选择文件上传

#import "ViewController.h"

@interface ViewController () 

@property (nonatomic, strong) UIDocumentPickerViewController *documentPickerVC;

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
}

- (IBAction)tapSelectFileAction:(id)sender {
    dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(0.35 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
        [self presentViewController:self.documentPickerVC animated:YES completion:nil];
    });
}

/**
 初始化 UIDocumentPickerViewController
 
 @param allowedUTIs 支持的文件类型数组
 "public.content",
 "public.text",
 "public.source-code",
 "public.image",
 "public.audiovisual-content",
 "com.adobe.pdf",
 "com.apple.keynote.key",
 "com.microsoft.word.doc",
 "com.microsoft.excel.xls",
 "com.microsoft.powerpoint.ppt"
 @param mode 支持的共享模式
 */
- (UIDocumentPickerViewController *)documentPickerVC {
    if (!_documentPickerVC) {
        NSArray *types = @[@"public.content",@"public.text"];
        self.documentPickerVC = [[UIDocumentPickerViewController alloc] initWithDocumentTypes:types inMode:UIDocumentPickerModeOpen];
        // 设置代理
        _documentPickerVC.delegate = self;
        // 设置模态弹出方式
        _documentPickerVC.modalPresentationStyle = UIModalPresentationFormSheet;
    }
    return _documentPickerVC;
}

#pragma mark - UIDocumentPickerDelegate

- (void)documentPicker:(UIDocumentPickerViewController *)controller didPickDocumentsAtURLs:(NSArray *)urls {
    // 获取授权
    BOOL fileUrlAuthozied = [urls.firstObject startAccessingSecurityScopedResource];
    if (fileUrlAuthozied) {
        // 通过文件协调工具来得到新的文件地址，以此得到文件保护功能
        NSFileCoordinator *fileCoordinator = [[NSFileCoordinator alloc] init];
        NSError *error;
        
        [fileCoordinator coordinateReadingItemAtURL:urls.firstObject options:0 error:&error byAccessor:^(NSURL *newURL) {
            // 读取文件
            NSString *fileName = [newURL lastPathComponent];
            NSError *error = nil;
            NSData *fileData = [NSData dataWithContentsOfURL:newURL options:NSDataReadingMappedIfSafe error:&error];
            if (error) {
                // 读取出错
            } else {
                // 上传
                NSLog(@"fileName : %@", fileName);
                // [self uploadingWithFileData:fileData fileName:fileName fileURL:newURL];
            }
            [self dismissViewControllerAnimated:YES completion:NULL];
        }];
        [urls.firstObject stopAccessingSecurityScopedResource];
    } else {
        // 授权失败
    }
}

@end