小编Ana*_*ore的帖子

我正在尝试使用文件应用程序一次导入/选择多个文件UIDocumentPickerViewController.

尝试设置,allowsMultipleSelection = true但在呈现选择器时仍然没有" 选择 "选项.

代码段:

UIDocumentPickerViewController *dvc = [[UIDocumentPickerViewController alloc]initWithDocumentTypes:arrContents inMode:UIDocumentPickerModeImport];
dvc.delegate = self;
dvc.allowsMultipleSelection = true;
[self presentViewController:dvc animated:true completion:nil];

截图:

我正在尝试从我的应用程序实现捕获图像和视频,现在从iOS 10开始,"AVCaptureStillImageOutput"已被弃用.

请帮我在Objective-C中实现AVCapturePhotoOutput.

这是我的示例代码:

_avCaptureOutput = [[AVCapturePhotoOutput alloc]init];
_avSettings = [AVCapturePhotoSettings photoSettings];


AVCaptureSession* captureSession = [[AVCaptureSession alloc] init];
[captureSession startRunning];



AVCaptureConnection *connection = [self.movieOutput connectionWithMediaType:AVMediaTypeVideo];

if (connection.active)
{
    //connection is active
    NSLog(@"Connection is active");

    id previewPixelType = _avSettings.availablePreviewPhotoPixelFormatTypes.firstObject;
    NSDictionary *format = @{(NSString*)kCVPixelBufferPixelFormatTypeKey:previewPixelType,(NSString*)kCVPixelBufferWidthKey:@160,(NSString*)kCVPixelBufferHeightKey:@160};

    _avSettings.previewPhotoFormat = format;

    [_avCaptureOutput capturePhotoWithSettings:_avSettings delegate:self];


}
else
{
    NSLog(@"Connection is not active");
    //connection is not active
    //try to change self.captureSession.sessionPreset,
    //or change videoDevice.activeFormat
}

我正打算在来电时获取来电显示(电话号码).TrueCaller实现了这一点,他们获得了来电者的电话号码.

我发现了这个信息:1.CoreTelephony框架(它只提供呼叫状态)2.Apple的9.0更新:"可能"联系人同步.使用邮件应用程序并检测传入的电话号码.

我需要在结构类型的变量中跟踪更新。是否可以在Swift中的struct变量上添加观察者？

例：

struct MyCustomStruct {
    var error:Error?
    var someVar:String?
}

class MyClass{
  var myCustomStruct:MyCustomStruct?
}

我想在myCustomStruct变量上添加一个观察者。