到了这个时候，我们需要一个更多参数的二维码生成方法接口了，这次新增的参数应该包括插入图片、圆角半径这些参数，因此方法如下：
+ (UIImage *)imageOfQRFromURL: (NSString *)networkAddress codeSize: (CGFloat)codeSize red: (NSUInteger)red green: (NSUInteger)green blue: (NSUInteger)blue insertImage: (UIImage *)insertImage roundRadius: (CGFloat)roundRadius {
if (!networkAddress || (NSNull *)networkAddress == [NSNull null]) { return nil; }
/** 颜色不可以太接近白色*/
NSUInteger rgb = (red << 16) + (green << 8) + blue;
NSAssert((rgb & 0xffffff00) <= 0xd0d0d000, @"The color of QR code is two close to white color than it will diffculty to scan");
codeSize = [self validateCodeSize: codeSize];
CIImage * originImage = [self createQRFromAddress: networkAddress];
UIImage * progressImage = [self excludeFuzzyImageFromCIImage: originImage size: codeSize]; //到了这里二维码已经可以进行扫描了
UIImage * effectiveImage = [self imageFillBlackColorAndTransparent: progressImage red: red green: green blue: blue]; //进行颜色渲染后的二维码
return [self imageInsertedImage: effectiveImage insertImage: insertImage radius: roundRadius];
}
这次的生成方法同样也只需要进行一次额外的调用方法操作，在插入图片的时候我们需要注意，类似微信的图中图二维码中间的小头像是有一个圆角的白色边缘的，这个边缘的加入让头像显示的更加自然。那么要完成这个效果，我额外在项目中加入了一张白色背景的小图，同样对这张图片进行圆角化处理，然后加在头像的下面。作为头像下方的白色背景图像尺寸应该大于头像图。制作画中画效果的具体实现如下：
/! 在二维码原图中心位置插入圆角图像/
+ (UIImage *)imageInsertedImage: (UIImage *)originImage insertImage: (UIImage *)insertImage radius: (CGFloat)radius
{
if (!insertImage) { return originImage; }
insertImage = [UIImage imageOfRoundRectWithImage: insertImage size: insertImage.size radius: radius];
UIImage * whiteBG = [UIImage imageNamed: @"whiteBG"];
whiteBG = [UIImage imageOfRoundRectWithImage: whiteBG size: whiteBG.size radius: radius];
//白色边缘宽度
const CGFloat whiteSize = 2.f;
CGSize brinkSize = CGSizeMake(originImage.size.width / 4, originImage.size.height / 4);
CGFloat brinkX = (originImage.size.width - brinkSize.width) * 0.5;
CGFloat brinkY = (originImage.size.height - brinkSize.height) * 0.5;
CGSize imageSize = CGSizeMake(brinkSize.width - 2 * whiteSize, brinkSize.height - 2 * whiteSize);
CGFloat imageX = brinkX + whiteSize;
CGFloat imageY = brinkY + whiteSize;
UIGraphicsBeginImageContext(originImage.size);
[originImage drawInRect: (CGRect){ 0, 0, (originImage.size) }];
[whiteBG drawInRect: (CGRect){ brinkX, brinkY, (brinkSize) }];
[insertImage drawInRect: (CGRect){ imageX, imageY, (imageSize) }];
UIImage * resultImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return resultImage;
}
- (UIImage *)imageOfRoundRectWithImage: (UIImage *)image size: (CGSize)size radius: (CGFloat)radius
{
if (!image) { return nil; }
const CGFloat width = size.width;
const CGFloat height = size.height;
radius = MAX(5.f, radius);
radius = MIN(10.f, radius);
UIImage * img = image;
CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
CGContextRef context = CGBitmapContextCreate(NULL, width, height, 8, 4 * width, colorSpace, kCGImageAlphaPremultipliedFirst);
CGRect rect = CGRectMake(0, 0, width, height);
//绘制圆角
CGContextBeginPath(context);
addRoundRectToPath(context, rect, radius, img.CGImage);
CGImageRef imageMasked = CGBitmapContextCreateImage(context);
img = [UIImage imageWithCGImage: imageMasked];
CGContextRelease(context);
CGColorSpaceRelease(colorSpace);
CGImageRelease(imageMasked);
return img;
}
