ios 7.1 flash 模式不工作

Question

这是我在 iphone 上更改闪光灯模式的代码。

在ios7.0中工作:flashmode(0,1,-1)

在 ios7.1 中不工作:flashmode(0,0,0)

//UIImagePickerControllerCameraFlashModeOff  = -1,
//UIImagePickerControllerCameraFlashModeAuto = 0,
//UIImagePickerControllerCameraFlashModeOn   = 1

NSInteger flashMode = self.pickerReference.cameraFlashMode;

NSLog(@"flashmode %i",flashMode);

if (flashMode == UIImagePickerControllerCameraFlashModeAuto) {
    [(UIButton *)sender setImage:[UIImage imageNamed:@"flashYesComposeButton.png"] forState:UIControlStateNormal];
    self.pickerReference.cameraFlashMode = UIImagePickerControllerCameraFlashModeOn;
}

else if (flashMode == UIImagePickerControllerCameraFlashModeOn) {
    [(UIButton *)sender setImage:[UIImage imageNamed:@"flashNoComposeButton.png"] forState:UIControlStateNormal];
    self.pickerReference.cameraFlashMode = UIImagePickerControllerCameraFlashModeOff;
}

else if (flashMode == UIImagePickerControllerCameraFlashModeOff)
{
    [(UIButton *)sender setImage:[UIImage imageNamed:@"flashAutoComposeButton.png"] forState:UIControlStateNormal];
    self.pickerReference.cameraFlashMode = UIImagePickerControllerCameraFlashModeAuto;
}

Answer 1

我之前遇到过那个错误

问题是无论 ios 7.1 中的真实闪光状态是什么，它总是返回 UIImagePickerControllerCameraFlashModeAuto。有趣的是，如果你将闪光灯模式设置为UIImagePickerControllerCameraFlashModeOff，闪光灯会真正关闭，但如果你询问状态，它仍然是UIImagePickerControllerCameraFlashModeAuto。

所以我通过保留自己的“flashState”解决了我的问题。单击时，我手动更改自己的状态，除了 UIImagePickerController 之外，我从不相信发回的状态。

@property (nonatomic) UIImagePickerControllerCameraFlashMode flashMode;

点击按钮时:

       if (self.flashMode == UIImagePickerControllerCameraFlashModeAuto) {  
            //toggle your button to "on"
            self.flashMode = UIImagePickerControllerCameraFlashModeOn;
        }else if (self.flashMode == UIImagePickerControllerCameraFlashModeOn){  
            //toggle your button to "Off"
            self.flashMode = UIImagePickerControllerCameraFlashModeOff;
        }else if (self.flashMode == UIImagePickerControllerCameraFlashModeOff){ 
            //toggle your button to "Auto"
            self.flashMode = UIImagePickerControllerCameraFlashModeAuto;
        }