Hello everyone I need help with my iOS app. How can I get the background color of the image (that I insert in UIImageView) exactly where I tap. I create a Tap Gesture Recognizer but I do not know how to read the background color where I tap.
add gesture in your control
UITapGestureRecognizer * tapRecognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(tapGesture:)];
[lblSlider addGestureRecognizer:tapRecognizer];
lblSlider.userInteractionEnabled = YES;
after add this method
- (void)tapGesture:(UITapGestureRecognizer *)recognizer
{
CGPoint point1 = [recognizer locationInView:recognizer.view];
UIGraphicsBeginImageContext(recognizer.view.bounds.size);
CGContextRef context = UIGraphicsGetCurrentContext();
[recognizer.view.layer renderInContext:context];
int bpr = (int)CGBitmapContextGetBytesPerRow(context);
unsigned char * data = CGBitmapContextGetData(context);
if (data != NULL)
{
int offset = bpr*round(point1.y) + 4*round(point1.x);
int blue = data[offset+0];
int green = data[offset+1];
int red = data[offset+2];
int alpha = data[offset+3];
NSLog(@"%d %d %d %d", alpha, red, green, blue);
if (alpha == 0)
{
// Here is tap out of text
}
else
{
// Here is tap right into text
}
}
UIGraphicsEndImageContext();
}
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