ios - 如何删除图像的一部分，除了在ios中突出显示部分

Question

嗨，我已经完成了从画廊或相机获取图像的操作。当我单击该按钮时，我有一个按钮，再次从画廊或相机获取图像，当我触摸某个突出显示的部分时，它应该只显示在另一个 View 中。剩余部分应该被删除。请任何人帮助我如何做到这一点。帮助是赞赏。我写了这个代码

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
self.slider.hidden=NO;
UITouch *touch = [touches anyObject];
lastPoint = [touch locationInView:self.view];   //lastTouch is CGPoint  declared globally
}
//#pragma mark - Touch moved mehotd
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch *touch = [touches anyObject];
currentPoint = [touch locationInView:self.view1];    //currentTouch is CGPoint declared globally
CGColorRef strokeColor = [UIColor whiteColor].CGColor;
UIGraphicsBeginImageContext(view1.frame.size);
CGContextRef context = UIGraphicsGetCurrentContext();
[imageView1.image drawInRect:CGRectMake(0, 0, self.view1.frame.size.width, self.view1.frame.size.height)];
//canvasView is your UIImageView  object declared globally
CGContextSetLineCap(context, kCGLineCapRound);
CGContextSetLineWidth(context, slider.value);
CGContextSetStrokeColorWithColor(context, strokeColor);
CGContextSetBlendMode(context, kCGBlendModeClear);
CGContextBeginPath(context);
CGContextMoveToPoint(context, lastPoint.x, lastPoint.y);
CGContextAddLineToPoint(context, currentPoint.x, currentPoint.y);
CGContextStrokePath(context);
imageView1.image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
lastPoint = [touch locationInView:self.view1];
}
//#pragma mark - Touch end mehotd
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch *touch = [touches anyObject];
currentPoint = [touch locationInView:self.view1];
}

但它正在删除所选区域。但我不想删除所选区域(突出显示)。应删除未选择的部分。我尝试了很多，请任何人回复我如何做到这一点。感谢帮助

Answer 1

你的问题听起来不错。我想有人已经像同样的问题一样早点给出了答案。

请看下面

Let User Crop Photo in iOS App

希望对你有所帮助。一切顺利!! :)