如何在椭圆形或圆形上裁剪UIImage？
请给出关于如何裁剪椭圆形或圆形UIImage想法。 请指导我
#import <QuartzCore/QuartzCore.h> CALayer *imageLayer = YourImageview.layer; [imageLayer setCornerRadius:5]; [imageLayer setBorderWidth:1]; [imageLayer setMasksToBounds:YES];
通过增加半径会变得更加圆润。
只要图像是一个正方形，就可以用半个宽度作为圆angular来得到一个完美的圆：
[imageView.layer setCornerRadius:imageView.frame.size.width/2];
您还需要添加
[imageView.layer setMasksToBounds:YES];
几个星期前我开始研究这个问题。 我在这里尝试了所有的build议，没有一个能够很好地工作。 在RTFM的伟大传统中，我去阅读苹果关于Quartz 2D Programming的文档，并提出了这个问题。 请尝试一下，让我知道你走了。
代码可以相当容易地修改为裁剪到一个椭圆，或由path定义的任何其他形状。
确保你的项目中包含了Quartz 2D。
#include <math.h> + (UIImage*)circularScaleAndCropImage:(UIImage*)image frame:(CGRect)frame { // This function returns a newImage, based on image, that has been: // - scaled to fit in (CGRect) rect // - and cropped within a circle of radius: rectWidth/2 //Create the bitmap graphics context UIGraphicsBeginImageContextWithOptions(CGSizeMake(frame.size.width, frame.size.height), NO, 0.0); CGContextRef context = UIGraphicsGetCurrentContext(); //Get the width and heights CGFloat imageWidth = image.size.width; CGFloat imageHeight = image.size.height; CGFloat rectWidth = frame.size.width; CGFloat rectHeight = frame.size.height; //Calculate the scale factor CGFloat scaleFactorX = rectWidth/imageWidth; CGFloat scaleFactorY = rectHeight/imageHeight; //Calculate the centre of the circle CGFloat imageCentreX = rectWidth/2; CGFloat imageCentreY = rectHeight/2; // Create and CLIP to a CIRCULAR Path // (This could be replaced with any closed path if you want a different shaped clip) CGFloat radius = rectWidth/2; CGContextBeginPath (context); CGContextAddArc (context, imageCentreX, imageCentreY, radius, 0, 2*M_PI, 0); CGContextClosePath (context); CGContextClip (context); //Set the SCALE factor for the graphics context //All future draw calls will be scaled by this factor CGContextScaleCTM (context, scaleFactorX, scaleFactorY); // Draw the IMAGE CGRect myRect = CGRectMake(0, 0, imageWidth, imageHeight); [image drawInRect:myRect]; UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext(); UIGraphicsEndImageContext(); return newImage; }
在您的UIView类中包含以下代码，用您自己的图像名称replace“monk2.png”。
- (void)drawRect:(CGRect)rect { UIImage *originalImage = [UIImage imageNamed:[NSString stringWithFormat:@"monk2.png"]]; CGFloat oImageWidth = originalImage.size.width; CGFloat oImageHeight = originalImage.size.height; // Draw the original image at the origin CGRect oRect = CGRectMake(0, 0, oImageWidth, oImageHeight); [originalImage drawInRect:oRect]; // Set the newRect to half the size of the original image CGRect newRect = CGRectMake(0, 0, oImageWidth/2, oImageHeight/2); UIImage *newImage = [self circularScaleAndCropImage:originalImage frame:newRect]; CGFloat nImageWidth = newImage.size.width; CGFloat nImageHeight = newImage.size.height; //Draw the scaled and cropped image CGRect thisRect = CGRectMake(oImageWidth+10, 0, nImageWidth, nImageHeight); [newImage drawInRect:thisRect]; }
要有椭圆形的imageView并不困难。
您可以执行以下操作
UIBezierPath *path = [UIBezierPath bezierPathWithOvalInRect:yourImageView.bounds]; CAShapeLayer *maskLayer = [CAShapeLayer layer]; maskLayer.path = path.CGPath; yourImage.layer.mask = maskLayer;
如果传递给bezierPathWithOvalInRect的矩形是正方形，则图像将被裁剪为圆形。
SWIFT代码
let path = UIBezierPath(ovalIn: yourImageView.bounds) let maskLayer = CAShapeLayer() maskLayer.path = path.cgPath yourImage.layer.mask = maskLayer
经过漫长的search后，我find了正确的方法来圈选图像
从URL http://vocaro.com/trevor/blog/2009/10/12/resize-a-uiimage-the-right-way/下载支持存档文件;
#import "UIImage+RoundedCorner.h" #import "UIImage+Resize.h"
以下几行用于调整图像大小并将其转换为半径圆形
UIImage *mask = [UIImage imageNamed:@"mask.jpg"]; mask = [mask resizedImage:CGSizeMake(47, 47) interpolationQuality:kCGInterpolationHigh ]; mask = [mask roundedCornerImage:23.5 borderSize:1];
迅速
var vwImage = UIImageView(image: UIImage(named: "Btn_PinIt_Normal.png")) vwImage.frame = CGRectMake(0, 0, 100, 100) vwImage.layer.cornerRadius = vwImage.frame.size.width/2
制作一个RoundShape图像
第一步：在.h文件中
@property (strong, nonatomic) IBOutlet UIImageView *songImage;
第二步：在.m文件中
- (void)viewDidLoad { self.songImage.layer.cornerRadius = self.songImage.frame.size.width / 2; self.songImage.clipsToBounds = YES; //To give the Border and Border color of imageview self.songImage.layer.borderWidth = 1.0f; self.songImage.layer.borderColor = [UIColor colorWithRed:249/255.0f green:117/255.0f blue:44/255.0f alpha:1.0f].CGColor; }
或者Swift
cell.songImage.layer.cornerRadius = cell.songImage.frame.size.width / 2; cell.songImage.clipsToBounds = true //To give the Border and Border color of imageview cell.songImage.layer.borderWidth = 1.0 cell.songImage.layer.borderColor = UIColor(red: 50.0/255, green: 150.0/255, blue: 65.0/255, alpha: 1.0).CGColor
如果你只需要一个完美的圆形，改变UIImageView的形状可能会有所帮助。 只需将QuartzCore框架添加到您的项目中，并在显示imageView之前在生命周期的某个地方添加以下代码行：
#import <QuartzCore/QuartzCore.h> . . . //to crop your UIImageView to show only a circle yourImageView.layer.cornerRadius = yourImageView.frame.size.width/2; yourImageView.clipsToBounds = YES;
查看CGImageCreateWithMask 。 创build一个椭圆形的面具，然后将其应用于图像。
你应该参考这 …
// Create the image from a png file UIImage *image = [UIImage imageNamed:@"prgBinary.jpg"]; UIImageView *imageView = [[UIImageView alloc] initWithImage:image]; // Get size of current image CGSize size = [image size]; // Frame location in view to show original image [imageView setFrame:CGRectMake(0, 0, size.width, size.height)]; [[self view] addSubview:imageView]; [imageView release]; // Create rectangle that represents a cropped image // from the middle of the existing image CGRect rect = CGRectMake(size.width / 4, size.height / 4 , (size.width / 2), (size.height / 2)); //oval logic goes here // Create bitmap image from original image data, // using rectangle to specify desired crop area CGImageRef imageRef = CGImageCreateWithImageInRect([image CGImage], rect); UIImage *img = [UIImage imageWithCGImage:imageRef]; CGImageRelease(imageRef); // Create and show the new image from bitmap data imageView = [[UIImageView alloc] initWithImage:img]; [imageView setFrame:CGRectMake(0, 200, (size.width / 2), (size.height / 2))]; [[self view] addSubview:imageView]; [imageView release];
SWIFT 3的答案来自@Mohammad Sadiq
let path = UIBezierPath.init(ovalIn: workingImgaeView.bounds) let maskLayer = CAShapeLayer(layer: layer) maskLayer.path = path.cgPath workingImgaeView.layer.mask = maskLayer
