经过一些研究,你似乎不能做我想做的事.下面是我编写的另一个选项,如果在iOS 8+上,我会弹出一个对话框并自动打开设置应用程序.
注意:
- 由于iOS 10,您需要在信息中指定
NSCameraUsageDescription
个密钥.plist必须能够请求摄像头访问,否则你的应用程序将在运行时崩溃.
- 一旦用户更改了你的应用程序的任何权限,就会终止你的应用程序.在用户点击"Go"按钮之前,相应地处理并保存任何需要的数据.
- 在iOS 8和iOS 11之间的某个时刻,苹果不再要求用户touch 设置应用程序中的隐私单元,以便访问和更改摄像头设置.您可能需要根据用户使用的iOS版本更改用户在设置应用程序中应该执行的操作说明.如果有人想在下面留下 comments ,告诉我们到底是什么版本的iOS,那就太棒了.
- 截至本答案的最后一次编辑,以下代码正在iOS 14.2上运行.
Swift 5.2:
在视图控制器的顶部:
import AVFoundation
在打开相机视图之前:
@IBAction func goToCamera()
{
let status = AVCaptureDevice.authorizationStatus(for: .video)
switch (status)
{
case .authorized:
self.popCamera()
case .notDetermined:
AVCaptureDevice.requestAccess(for: .video) { (granted) in
if (granted)
{
self.popCamera()
}
else
{
self.camDenied()
}
}
case .denied:
self.camDenied()
case .restricted:
let alert = UIAlertController(title: "Restricted",
message: "You've been restricted from using the camera on this device. Without camera access this feature won't work. Please contact the device owner so they can give you access.",
preferredStyle: .alert)
let okAction = UIAlertAction(title: "OK", style: .default, handler: nil)
alert.addAction(okAction)
self.present(alert, animated: true, completion: nil)
@unknown default:
fatalError()
}
}
带有完成块的拒绝alert :
func camDenied()
{
DispatchQueue.main.async
{
var alertText = "It looks like your privacy settings are preventing us from accessing your camera to do barcode scanning. You can fix this by doing the following:\n\n1. Close this app.\n\n2. Open the Settings app.\n\n3. Scroll to the bottom and select this app in the list.\n\n4. Turn the Camera on.\n\n5. Open this app and try again."
var alertButton = "OK"
var goAction = UIAlertAction(title: alertButton, style: .default, handler: nil)
if UIApplication.shared.canOpenURL(URL(string: UIApplication.openSettingsURLString)!)
{
alertText = "It looks like your privacy settings are preventing us from accessing your camera to do barcode scanning. You can fix this by doing the following:\n\n1. Touch the Go button below to open the Settings app.\n\n2. Turn the Camera on.\n\n3. Open this app and try again."
alertButton = "Go"
goAction = UIAlertAction(title: alertButton, style: .default, handler: {(alert: UIAlertAction!) -> Void in
UIApplication.shared.open(URL(string: UIApplication.openSettingsURLString)!, options: [:], completionHandler: nil)
})
}
let alert = UIAlertController(title: "Error", message: alertText, preferredStyle: .alert)
alert.addAction(goAction)
self.present(alert, animated: true, completion: nil)
}
}
Objective-C:
在视图控制器的顶部:
#import <AVFoundation/AVFoundation.h>
在打开相机视图之前:
- (IBAction)goToCamera
{
AVAuthorizationStatus authStatus = [AVCaptureDevice authorizationStatusForMediaType:AVMediaTypeVideo];
if(authStatus == AVAuthorizationStatusAuthorized)
{
[self popCamera];
}
else if(authStatus == AVAuthorizationStatusNotDetermined)
{
NSLog(@"%@", @"Camera access not determined. Ask for permission.");
[AVCaptureDevice requestAccessForMediaType:AVMediaTypeVideo completionHandler:^(BOOL granted)
{
if(granted)
{
NSLog(@"Granted access to %@", AVMediaTypeVideo);
[self popCamera];
}
else
{
NSLog(@"Not granted access to %@", AVMediaTypeVideo);
[self camDenied];
}
}];
}
else if (authStatus == AVAuthorizationStatusRestricted)
{
// My own Helper class is used here to pop a dialog in one simple line.
[Helper popAlertMessageWithTitle:@"Error" alertText:@"You've been restricted from using the camera on this device. Without camera access this feature won't work. Please contact the device owner so they can give you access."];
}
else
{
[self camDenied];
}
}
拒绝alert :
- (void)camDenied
{
NSLog(@"%@", @"Denied camera access");
NSString *alertText;
NSString *alertButton;
BOOL canOpenSettings = (&UIApplicationOpenSettingsURLString != NULL);
if (canOpenSettings)
{
alertText = @"It looks like your privacy settings are preventing us from accessing your camera to do barcode scanning. You can fix this by doing the following:\n\n1. Touch the Go button below to open the Settings app.\n\n2. Turn the Camera on.\n\n3. Open this app and try again.";
alertButton = @"Go";
}
else
{
alertText = @"It looks like your privacy settings are preventing us from accessing your camera to do barcode scanning. You can fix this by doing the following:\n\n1. Close this app.\n\n2. Open the Settings app.\n\n3. Scroll to the bottom and select this app in the list.\n\n4. Turn the Camera on.\n\n5. Open this app and try again.";
alertButton = @"OK";
}
UIAlertView *alert = [[UIAlertView alloc]
initWithTitle:@"Error"
message:alertText
delegate:self
cancelButtonTitle:alertButton
otherButtonTitles:nil];
alert.tag = 3491832;
[alert show];
}
代表调用UIAlertView:
- (void)alertView:(UIAlertView *)alertView didDismissWithButtonIndex:(NSInteger)buttonIndex
{
if (alertView.tag == 3491832)
{
BOOL canOpenSettings = (&UIApplicationOpenSettingsURLString != NULL);
if (canOpenSettings)
[[UIApplication sharedApplication] openURL:[NSURL URLWithString:UIApplicationOpenSettingsURLString]];
}
}