xCode 创建 UIImagePickerController 并引用它

Question

for my app I want to create a custom camera overlay and create a UIImagePickerController to start recording video. (below)

- (IBAction)RecordVideo:(UIButton *)sender {

    //initialise camera view
    UIImagePickerController *cameraUI = [[UIImagePickerController alloc] init];
    cameraUI.sourceType = UIImagePickerControllerSourceTypeCamera;
    cameraUI.cameraDevice = UIImagePickerControllerCameraDeviceFront;
    cameraUI.showsCameraControls = NO;
    cameraUI.navigationBarHidden = YES;
    cameraUI.toolbarHidden = YES;

    OverlayView *overlay = [[OverlayView alloc]
                        initWithFrame:CGRectMake(0, 0, 20,20)];

    cameraUI.cameraOverlayView = overlay;

    [self presentViewController:cameraUI animated:YES completion:nil];
}

as part of the cameraOverlayView I've instantiated a UIButton:

- (id)initWithFrame:(CGRect)frame {
    if (self = [super initWithFrame:frame]) {
        //clear the background color of the overlay
        self.opaque = NO;
        self.backgroundColor = [UIColor clearColor];

        ... some overlay UI stuff


        UIButton *captureBtn = [UIButton buttonWithType:UIButtonTypeRoundedRect];
        UIImage *captureBtnImg = [UIImage imageNamed:@"captureBtn.png"];
        [captureBtn setBackgroundImage:captureBtnImg forState:UIControlStateNormal];
        captureBtn.frame = CGRectMake(self.frame.size.width/2 - 15,
                                      430,
                                      80,
                                      80);
        [self addSubview:captureBtn];
    }
    return self;
}

So how do I create an IBAction for this button which can then make the UIImagePickerController cameraUI start recording?

If somebody could also explain to me how the IBActions are called from specific buttons only that would also be amazing because that seems like black magic to me?

Answer 1

You can add target like this,

[captureBtn addTarget:self action:@selector(captureBtnclick:) forControlEvents:UIControlEventTouchUpInside];

and you action method shoulbe like this

-(void)captureBtnclick :(UIButton*)sender{

//handle your task on click here

}

second thing why you are adding layer on it? you can use default video recording from imagePicker by setting mediatype like

cameraUI.mediaTypes = [[NSArray alloc] initWithObjects: (NSString *) kUTTypeMovie, nil];

Update accroding to comment

you can use on button click,

 [picker startVideoCapture]; //in your case cameraUI i think

Update 2 :

in your .h file,

@property UIImagePickerController *cameraUI;

then in your method RecordVideo use like,

self.cameraUI = [[UIImagePickerController alloc] init];
self.cameraUI.sourceType = UIImagePickerControllerSourceTypeCamera;

 //etc.....

By this way you can use camaraUI in whole class by self

hope this will help :)