Add view onto UIViewController - xcode

Question

I have made a UIImagePicker
UIImagePickerController *picker = [[UIImagePickerController alloc] init];
picker.delegate = self;
picker.allowsEditing = YES;
picker.sourceType = UIImagePickerControllerSourceTypeCamera;
picker.cameraDevice = UIImagePickerControllerCameraDeviceFront;
picker.mediaTypes = [[NSArray alloc] initWithObjects: (NSString *) kUTTypeMovie, nil];
And I want to add a half circle to to so I do this,
CGContextRef gc = UIGraphicsGetCurrentContext();
CGContextBeginPath(gc);
CGContextAddArc(gc, 100, 100, 50, -M_PI_2, M_PI_2, 1);
CGContextClosePath(gc); // could be omitted
CGContextSetFillColorWithColor(gc, [UIColor cyanColor].CGColor);
CGContextFillPath(gc);
UIView *someView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 400, 400)];
[someView.layer renderInContext:gc];
[picker setCameraOverlayView:someView];
But then when I show the picker like so
[self presentViewController:picker animated:YES completion:NULL];
I don't see the semicircle? Why is this happening?
Thanks

Answer 1

Hey you are not going on proper way.
Do the below step it will help you...
See the below answer..
https://stackoverflow.com/questions/5552210/uitableviewcells-invalid-context-trying-to-draw
CircleView.h
#import <UIKit/UIKit.h>
#interface CircleView : UIView
#end
CircleView.m
#import "CircleView.h"
#implementation CircleView
- (void)drawRect:(CGRect)rect
{
CGContextRef gc = UIGraphicsGetCurrentContext();
CGContextBeginPath(gc);
CGContextAddArc(gc, 100, 100, 50, -M_PI_2, M_PI_2, 1);
CGContextClosePath(gc); // could be omitted
CGContextSetFillColorWithColor(gc, [UIColor cyanColor].CGColor);
CGContextFillPath(gc);
}
#end
Implimenttion of adding half circle in your imagepicker is here
UIImagePickerController *controller = [[UIImagePickerController alloc]init];
controller.delegate=self;
controller.sourceType = UIImagePickerControllerSourceTypeCamera;
[self presentViewController:controller animated:YES completion:^{
CircleView *someView = [[CircleView alloc] initWithFrame:CGRectMake(0, 0, 400, 400)];
[someView setBackgroundColor:[UIColor colorWithWhite:0.5 alpha:0.5]];
[controller setCameraOverlayView:someView];
}];