我的问题对你来说可能很容易.
我想在我的照片编辑应用程序中为UIImage添加白色边框.我找到了一些问题和答案How can i take an UIImage and give it a black border?.
大多数答案都是为UIImageView添加边框.在我的情况下,我需要为UIImage添加一个边框宽度可调的边框.
请问你能帮帮我吗？
解决方法
您可以通过访问UIImageView的图层属性来设置CALayer上的边框属性.
首先,添加Quartz
#import <QuartzCore/QuartzCore.h>
设置属性：
[[yourImageView layer] setBorderWidth:2.0f]; [[yourImageView layer] setBorderColor:[UIColor whiteColor].CGColor];
编辑1
由于需要使用边框保存图像,请使用以下内容.
- (UIImage *)addBorderToImage:(UIImage *)image {
CGImageRef bgimage = [image CGImage];
float width = CGImageGetWidth(bgimage);
float height = CGImageGetHeight(bgimage);
// Create a temporary texture data buffer
void *data = malloc(width * height * 4);
// Draw image to buffer
CGContextRef ctx = CGBitmapContextCreate(data,width,height,8,width * 4,CGImageGetColorSpace(image.CGImage),kCGImageAlphaPremultipliedLast);
CGContextDrawImage(ctx,CGRectMake(0,(CGFloat)width,(CGFloat)height),bgimage);
//Set the stroke (pen) color
CGContextSetStrokeColorWithColor(ctx,[UIColor greenColor].CGColor);
//Set the width of the pen mark
CGFloat borderWidth = (float)width*0.05;
CGContextSetLineWidth(ctx,borderWidth);
//Start at 0,0 and draw a square
CGContextMoveToPoint(ctx,0.0,0.0);
CGContextAddLineToPoint(ctx,height);
CGContextAddLineToPoint(ctx,0.0);
CGContextAddLineToPoint(ctx,0.0);
//Draw it
CGContextStrokePath(ctx);
// write it to a new image
CGImageRef cgimage = CGBitmapContextCreateImage(ctx);
UIImage *newImage = [UIImage imageWithCGImage:cgimage];
CFRelease(cgimage);
CGContextRelease(ctx);
// auto-released
return newImage;
}
