建立一个公用类YDQRCode管理二维码相关的方法
#import <Foundation/Foundation.h>
#import <UIKit/UIKit.h>
@interface YDQRCode : NSObject
在.h文件中
/**
根据链接，获取输出的二维码
+ (CIImage *)createQRForString:(NSString *)qrString ;
/**
根据CIImage生成指定大小的UIImage
@param image CIImage
@param size 图片宽度
+(UIImage *)createNonInterpolatedUIImageFormCIImage:(CIImage *)image withSize:(CGFloat) size;
/**
默认产生的黑白色的二维码图片；我们可以让它产生其它颜色的二维码图片，例如：蓝白色的二维码图片
+(UIImage *)specialColorImage:(UIImage*)image withRed:(CGFloat)red green:(CGFloat)green blue:(CGFloat)blue;
/**
使用核心绘图框架CG（Core Graphics）对象操作，合并二维码图片和用于中间显示的图标图片
+(UIImage *)addIconToQRCodeImage:(UIImage *)image withIcon:(UIImage *)icon withIconSize:(CGSize)iconSize;
/**
使用核心绘图框架CG（Core Graphics）对象操作，合并二维码图片和用于中间显示的图标图片
+(UIImage *)addIconToQRCodeImage:(UIImage *)image withIcon:(UIImage *)icon withScale:(CGFloat)scale;
在.m文件中实现具体的方法：
#pragma mark - Private Methods
void ProviderReleaseData (void *info, const void *data, size_t size){
free((void*)data);
}
#pragma mark - Public Methods
+(CIImage *)createQRForString:(NSString *)qrString {
//创建过滤器,使用CIFilter滤镜类生成二维码
CIFilter * filter = [CIFilter filterWithName:@"CIQRCodeGenerator"];
//恢复默认
[filter setDefaults];
//给过滤器添加数据（正则表达式/账号和密码）
NSData * data = [qrString dataUsingEncoding:NSUTF8StringEncoding];
// 设置内容和纠错级别
[filter setValue:data forKey:@"inputMessage"];
[filter setValue:@"M" forKey:@"inputCorrectionLevel"];
// 返回CIImage
return filter.outputImage;
}
+(UIImage *)createNonInterpolatedUIImageFormCIImage:(CIImage *)image withSize:(CGFloat) size{
CGRect extent = CGRectIntegral(image.extent);
CGFloat scale = MIN(size/CGRectGetWidth(extent), size/CGRectGetHeight(extent));
//创建bitmap
size_t width = CGRectGetWidth(extent) * scale;
size_t height = CGRectGetHeight(extent) * scale;
//创建一个DeviceGray颜色空间
CGColorSpaceRef cs = CGColorSpaceCreateDeviceGray();
CGContextRef bitmapRef = CGBitmapContextCreate(nil, width, height, 8, 0, cs, (CGBitmapInfo)kCGImageAlphaNone);
CIContext *context = [CIContext contextWithOptions:nil];
CGImageRef bitmapImage = [context createCGImage:image fromRect:extent];
CGContextSetInterpolationQuality(bitmapRef, kCGInterpolationNone);
CGContextScaleCTM(bitmapRef, scale, scale);
CGContextDrawImage(bitmapRef, extent, bitmapImage);
// 2.保存bitmap到图片
CGImageRef scaledImage = CGBitmapContextCreateImage(bitmapRef);
CGContextRelease(bitmapRef);
CGImageRelease(bitmapImage);
return [UIImage imageWithCGImage:scaledImage];
}
+ (UIImage *)specialColorImage:(UIImage*)image withRed:(CGFloat)red green:(CGFloat)green blue:(CGFloat)blue {
const int imageWidth = image.size.width;
const int imageHeight = image.size.height;
size_t bytesPerRow = imageWidth * 4;
uint32_t* rgbImageBuf = (uint32_t*)malloc(bytesPerRow * imageHeight);
//Create context
CGColorSpaceRef colorSpaceRef = CGColorSpaceCreateDeviceRGB();
CGContextRef contextRef = CGBitmapContextCreate(rgbImageBuf, imageWidth, imageHeight, 8, bytesPerRow, colorSpaceRef, kCGBitmapByteOrder32Little | kCGImageAlphaNoneSkipLast);
CGContextDrawImage(contextRef, CGRectMake(0, 0, imageWidth, imageHeight), image.CGImage);
//Traverse pixe
int pixelNum = imageWidth * imageHeight;
uint32_t* pCurPtr = rgbImageBuf;
for (int i = 0; i < pixelNum; i++, pCurPtr++){
if ((*pCurPtr & 0xFFFFFF00) < 0x99999900){
//Change color
uint8_t* ptr = (uint8_t*)pCurPtr;
ptr[3] = red; //0~255
ptr[2] = green;
ptr[1] = blue;
}else{
uint8_t* ptr = (uint8_t*)pCurPtr;
ptr[0] = 0;
}
}
//Convert to image
CGDataProviderRef dataProviderRef = CGDataProviderCreateWithData(NULL, rgbImageBuf, bytesPerRow * imageHeight, ProviderReleaseData);
CGImageRef imageRef = CGImageCreate(imageWidth, imageHeight, 8, 32, bytesPerRow, colorSpaceRef,
kCGImageAlphaLast | kCGBitmapByteOrder32Little, dataProviderRef,
NULL, true, kCGRenderingIntentDefault);
CGDataProviderRelease(dataProviderRef);
UIImage* img = [UIImage imageWithCGImage:imageRef];
//Release
CGImageRelease(imageRef);
CGContextRelease(contextRef);
CGColorSpaceRelease(colorSpaceRef);
return img;
}
+(UIImage *)addIconToQRCodeImage:(UIImage *)image withIcon:(UIImage *)icon withIconSize:(CGSize)iconSize {
UIGraphicsBeginImageContext(image.size);
//通过两张图片进行位置和大小的绘制，实现两张图片的合并；其实此原理做法也可以用于多张图片的合并
CGFloat widthOfImage = image.size.width;
CGFloat heightOfImage = image.size.height;
CGFloat widthOfIcon = iconSize.width;
CGFloat heightOfIcon = iconSize.height;
[image drawInRect:CGRectMake(0, 0, widthOfImage, heightOfImage)];
[icon drawInRect:CGRectMake((widthOfImage-widthOfIcon)/2, (heightOfImage-heightOfIcon)/2,
widthOfIcon, heightOfIcon)];
UIImage *img = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return img;
}
+(UIImage *)addIconToQRCodeImage:(UIImage *)image withIcon:(UIImage *)icon withScale:(CGFloat)scale {
UIGraphicsBeginImageContext(image.size);
//通过两张图片进行位置和大小的绘制，实现两张图片的合并；其实此原理做法也可以用于多张图片的合并
CGFloat widthOfImage = image.size.width;
CGFloat heightOfImage = image.size.height;
CGFloat widthOfIcon = widthOfImage/scale;
CGFloat heightOfIcon = heightOfImage/scale;
[image drawInRect:CGRectMake(0, 0, widthOfImage, heightOfImage)];
[icon drawInRect:CGRectMake((widthOfImage-widthOfIcon)/2, (heightOfImage-heightOfIcon)/2,
widthOfIcon, heightOfIcon)];
UIImage *img = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return img;
}
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