How to know if iPhone camera is ready to take picture?

Question

When [camera takePicture] is called before the camera is ready, it spits out this message:

UIImagePickerController: ignoring request to take pictu

Answer 1

If you are using UIImagePickerController, following is the code for video, similar code implies for image as well.

UIImagePickerController *picker;
BOOL cameraIsOn;

Then check for camera device available

if ([UIImagePickerController isCameraDeviceAvailable:[picker cameraDevice]]) {
            if (cameraIsOn) {
                NSLog(@"stop camera");
                [picker stopVideoCapture];
                cameraIsOn = FALSE;
            }
            else {
                NSLog(@"start camera");
                [picker startVideoCapture];
                self.videoTimer =  [NSTimer scheduledTimerWithTimeInterval:1 target:self selector:@selector(changeValue) userInfo:nil repeats:YES];
                cameraIsOn = TRUE;
            }
        }