如何使用UIBezierPath裁剪图像？

我想从UIBezierpath封闭的路径中获取图像（请参阅图像）。我使用drawRect方法在UIView上绘制图像，并且还绘制了使用drawRect方法的线条。如何获得特定的封闭路径图像？请帮帮我。提前致谢。如何使用UIBezierPath裁剪图像？

此代码用于绘制贝塞尔路径。

UIBezierPath *aPath = [UIBezierPath bezierPath]; 
for (NSString *pointString in pointArray) { 
    if ([pointArray indexOfObject:pointString] == 0) 
     [aPath moveToPoint:CGPointFromString(pointString)]; 
    else 
     [aPath addLineToPoint:CGPointFromString(pointString)]; 
} 
[aPath closePath];

enter image description here

来源

2012-10-31 Mani

我们如何可以借鉴的UIImageView一条线，当我尝试借鉴UIView的一个线路工作正常，但在UIImageView的不工作，你能不能帮我请 – dineshprasanna

玛尼你实现了你的目标吗？ – amar

嗨，你可以回答你自己的问题.... – Rajneesh071

您可以使用一个shapeLayer。喜欢的东西，

UIBezierPath *aPath = [UIBezierPath bezierPath]; 
for (NSString *pointString in pointArray) { 
    if ([pointArray indexOfObject:pointString] == 0) 
     [aPath moveToPoint:CGPointFromString(pointString)]; 
    else 
     [aPath addLineToPoint:CGPointFromString(pointString)]; 
} 
[aPath closePath]; 

CAShapeLayer *shapeLayer = [CAShapeLayer layer]; 
shapeLayer.path = aPath.CGPath; 
[view.layer setMask:shapeLayer];//or make it as [imageview.layer setMask:shapeLayer]; 
//and add imageView as subview of whichever view you want. draw the original image 
//on the imageview in that case

为了得到它作为一个图像，

UIGraphicsBeginImageContext(view.bounds.size); 
[view.layer renderInContext:UIGraphicsGetCurrentContext()]; 
UIImage *image = UIGraphicsGetImageFromCurrentImageContext(); 
UIGraphicsEndImageContext();

image应该有相应的图像。

来源

2012-11-02 00:21:23 iDev

谢谢ACB ...如何从UIBezierpath中获取图像。 – Mani

更新了我的答案。核实。 – iDev

谢谢...我试过这个，它得到的图像和背景是白色的。我只需要UIBezier路径部分的图像（请参阅图像猫头部）。你明白我的意思？ – Mani

如果您绘制代码一切都只是用 - addClip，即：

UIBezierPath *aPath = [UIBezierPath bezierPath]; 
for (NSString *pointString in pointArray) { 
    if ([pointArray indexOfObject:pointString] == 0) 
     [aPath moveToPoint:CGPointFromString(pointString)]; 
    else 
     [aPath addLineToPoint:CGPointFromString(pointString)]; 
} 
[aPath closePath]; 


CGContextSaveGState(context); 
{ 
    [aPath addClip]; 
    // draw image 
    [aPath stroke]; 
} 
CGContextRestoreGState(context);

来源

2012-11-02 04:09:36 hypercrypt

嗨，高加密...谢谢你的回复。 – Mani

如何从特定的UIBezierPath获取图像。 – Mani

创建一个图像上下文并使用'UIGraphicsGetImageFromCurrentImageContext（）' – hypercrypt

嗯，有几个是你必须要在通知的事情。

你传递你的UIImageView而不是你的UIView？
如果您是，是否启用了图像视图以进行触摸处理？
继承你的UIImageView并使用drawrect()为你处理这些东西。

如果你只想要图像的一部分（如猫），那么你需要按照UIBezierPath来掩盖图像。

更新

下面是一个完整的工作示例，将其更改为您的要求。

ViewController.h：

@interface ViewController : UIViewController 
{ 
    UIBezierPath *aPath; 
} 
@property (nonatomic,retain) NSMutableArray *pathArray; 
@property (nonatomic,retain) NSMutableDictionary *dic; 
@property (nonatomic,retain) IBOutlet UIImageView *imgView; 

@end

ViewController.m：

@interface ViewController() 
- (IBAction)Crop:(id)sender; 
@end 

@implementation ViewController 
@synthesize pathArray,dic,imgView; 
- (void)viewDidLoad 
{ 
    [super viewDidLoad]; 

} 
- (void) setClippingPath:(UIBezierPath *)clippingPath : (UIImageView *)imgView; 
{ 

    NSLog(@"Mask Paths %@",clippingPath); 

    CAShapeLayer *maskLayer = [CAShapeLayer layer]; 
    maskLayer.frame = self.imgView.frame; 
    maskLayer.path = [clippingPath CGPath]; 
    maskLayer.fillColor = [[UIColor whiteColor] CGColor]; 
    maskLayer.backgroundColor = [[UIColor clearColor] CGColor]; 


    self.imgView.layer.mask = maskLayer; 



} 
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event 
{ 

    UITouch *mytouch=[[touches allObjects] objectAtIndex:0]; 
    self->aPath = [[UIBezierPath alloc]init]; 
    [aPath moveToPoint:[mytouch locationInView:imgView]]; 

} 
-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event 
{ 

    UITouch *mytouch=[[touches allObjects] objectAtIndex:0]; 
    [aPath addLineToPoint:[mytouch locationInView:imgView 
         ]]; 

} 
-(void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event 
{ 

} 
- (IBAction)Crop:(id)sender 
{ 
    [self setClippingPath:aPath :imgView]; 
}

来源

2013-03-12 05:19:06

嗨，现在我们该如何将这个图层保存为背景清晰的uiimage？我尝试将CALayer self.imgView.layer.mask转换为UIImage，如http://stackoverflow.com/questions/3454356/uiimage-from-calayer-iphone-sdk中所述。但这不是理想的结果。 – ScarletWitch

你好umer sufyan。我如何开始了解uibezierpath？我试图阅读文档，但因为我只是一个新手，我很难找到一个握手。请指导我一些很好的uibezierpath教程。谢谢。 – UsamaMan

它迟了一点，但你应该渲染你的图层，并获得所需的UIImage .. –

这个工作对我来说...

UIBezierPath *path = ....//your path 
CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB(); 
CGContextRef context = CGBitmapContextCreate(nil, frame.size.width, frame.size.height, 8, 4*frame.size.width, colorSpace, (CGBitmapInfo)kCGImageAlphaPremultipliedFirst); 

CGContextAddPath(context, path.CGPath); 
CGContextClip(context); 
CGContextDrawImage(context, frame, image.CGImage); 

[UIImage imageWithCGImage:CGBitmapContextCreateImage(context)];

来源

2013-09-11 15:20:07 Camo

使用该吊舱ios-helpers

- (UIImage *)imageWithStrokeColor: (UIColor *)stroke_color andFillColor: (UIColor *)fill_color { 

    // adjust bounds to account for extra space needed for lineWidth 
    CGFloat width = self.bounds.size.width + self.lineWidth * 2; 
    CGFloat height = self.bounds.size.height + self.lineWidth * 2; 
    CGRect bounds = CGRectMake(self.bounds.origin.x, self.bounds.origin.y, width, height); 

    // create a view to draw the path in 
    UIView *view = [[UIView alloc] initWithFrame:bounds]; 

    // begin graphics context for drawing 
    UIGraphicsBeginImageContextWithOptions(view.frame.size, NO, [[UIScreen mainScreen] scale]); 

    // configure the view to render in the graphics context 
    [view.layer renderInContext:UIGraphicsGetCurrentContext()]; 

    // get reference to the graphics context 
    CGContextRef context = UIGraphicsGetCurrentContext(); 

    // reverse the y-axis to match the opengl coordinate space 
    CGContextScaleCTM(context, 1, -1); 
    CGContextTranslateCTM(context, 0, -view.bounds.size.height); 

    // translate matrix so that path will be centered in bounds 
    CGContextTranslateCTM(context, -(bounds.origin.x - self.lineWidth), -(bounds.origin.y - self.lineWidth)); 

    // stroke color 
    [stroke_color setStroke]; 
    [self stroke]; 

    //fill color 
    [fill_color setFill]; 
    [self fill]; 

    // get an image of the graphics context 
    UIImage *viewImage = UIGraphicsGetImageFromCurrentImageContext(); 

    // end the context 
    UIGraphicsEndImageContext(); 

    return viewImage; 
}

来源

2014-06-09 02:55:14 Yijun

你可以添加更多的细节到你的答案？包含指向文档和示例代码的链接是很好的，但是您能描述它到底是什么吗？ – bjb568

@ bjb568，对不起。这是代码。 – Yijun

好多了。 +1。 – bjb568

对于斯威夫特试试这个：ZImageCropper

ZImageCropper是使用下面的东西作为核心部件：

UIBezierPath
UITouch事件
CAShapeLayer
CoreGraphics在

来源

2015-11-12 19:24:57

IDEV的答案是优秀的，但如果你需要透明的背景，那么除了 UIGraphicsBeginImageContext(view.bounds.size); 你应该使用

UIGraphicsBeginImageContextWithOptions(view.bounds.size, NO, 1.0);

默认情况下，图像内容创建与不透明== YES，所以你必须改变它为NO。

来源

2016-04-05 09:14:20

// This Work 100%

- （无效）的touchesBegan：（NSSet中*）触摸withEvent：方法（的UIEvent *）事件{

mouseSwiped = NO; 
UITouch *touch = [touches anyObject]; 
lastPoint = [touch locationInView:self.view]; 
megView = [[UIImageView alloc]initWithFrame:CGRectMake(lastPoint.x , lastPoint.y , k_POINT_WIDTH , k_POINT_WIDTH)]; 
//[megView setImage:[UIImage imageNamed:@"b_image22.png"]]; 
[megView setContentMode:UIViewContentModeScaleToFill]; 
megView.alpha = 2; 
//megView.layer.backgroundColor = [UIColor whiteColor].CGColor; 
//megView.layer.cornerRadius = megView.frame.size.width/2; 
megView.clipsToBounds = YES; 
[self.main_uiview addSubview:megView]; 


self.bezierPath = [UIBezierPath bezierPath]; 
[self.bezierPath moveToPoint:lastPoint];

}

// Touchmove method 


- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event { 

mouseSwiped = YES; 
UITouch *touch = [touches anyObject]; 
CGPoint currentPoint = [touch locationInView:self.view]; 
UIGraphicsBeginImageContext(self.main_uiview.frame.size); 
[self.bg_imageview.image drawInRect:CGRectMake(0, 0, self.main_uiview.frame.size.width, self.main_uiview.frame.size.height)]; 
megView.frame = CGRectMake(currentPoint.x - k_POINT_WIDTH/2 , currentPoint.y - k_POINT_WIDTH/2 , k_POINT_WIDTH , k_POINT_WIDTH); 
CGContextMoveToPoint(UIGraphicsGetCurrentContext(), lastPoint.x, lastPoint.y); 
CGContextAddLineToPoint(UIGraphicsGetCurrentContext(), currentPoint.x, currentPoint.y); 
CGContextSetLineCap(UIGraphicsGetCurrentContext(), kCGLineCapRound); 
CGContextStrokePath(UIGraphicsGetCurrentContext()); 


CGContextSetRGBStrokeColor(UIGraphicsGetCurrentContext(), red,green ,blue, 0.20); 
CGContextSetBlendMode(UIGraphicsGetCurrentContext(), kCGBlendModeCopy); 
    self.bg_imageview.image = UIGraphicsGetImageFromCurrentImageContext(); 
    [self.bg_imageview setAlpha:opacity]; 

UIGraphicsEndImageContext(); 

lastPoint = currentPoint; 

[self.bezierPath addLineToPoint:lastPoint];

}

// TouchEnd Method 


    - (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event

{

[megView removeFromSuperview];

}

 // Image Crop Method 


    -(UIImage *)croppedImage 
    { 
UIImage *myImage = UIGraphicsGetImageFromCurrentImageContext(); 
UIGraphicsEndImageContext(); 
[self.bezierPath closePath]; 
CGContextSetRGBStrokeColor(UIGraphicsGetCurrentContext(), 0.0, 0.0, 0.0, 0.0); 
_b_image = self.bg_imageview.image; 
CGSize imageSize = _b_image.size; 
CGRect imageRect = CGRectMake(0, 0, imageSize.width, imageSize.height); 
UIGraphicsBeginImageContextWithOptions(imageSize, NO, [[UIScreen mainScreen] scale]); 
[self.bezierPath addClip]; 
[_b_image drawInRect:imageRect]; 

UIImage *croppedImage = UIGraphicsGetImageFromCurrentImageContext(); 
UIGraphicsEndImageContext(); 
return croppedImage;

}

来源

2017-06-02 07:04:25

如何使用UIBezierPath裁剪图像？

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