h文件
import@interface QrCodeGenerateVC : UIViewController
@end
.m文件
import "QrCodeGenerateVC.h"
@interface QrCodeGenerateVC ()
@property(nonatomic,strong) UIImageView *imageview;
@end
@implementation QrCodeGenerateVC
- (void)viewDidLoad {
[super viewDidLoad];
_imageview = [[UIImageView alloc]initWithFrame:CGRectMake(0, 40, SCREENWIDGH, SCREENWIDGH)];
[self.view addSubview:_imageview];
}
-(void)initErCodeWithString:(NSString *)dataString{
// 1.创建滤镜
CIFilter *filter = [CIFilter filterWithName:@"CIQRCodeGenerator"];
// 2.还原滤镜默认属性
[filter setDefaults];
// 3.设置需要生成二维码的数据到滤镜中
// OC中要求设置的是一个二进制数据
NSData *data = [dataString dataUsingEncoding:NSUTF8StringEncoding];
[filter setValue:data forKeyPath:@"InputMessage"];
// 4.从滤镜从取出生成好的二维码图片
CIImage *ciImage = [filter outputImage];
self.imageview.layer.shadowOffset = CGSizeMake(0, 0.5); // 设置阴影的偏移量
self.imageview.layer.shadowRadius = 1; // 设置阴影的半径
self.imageview.layer.shadowColor = [UIColor blackColor].CGColor; // 设置阴影的颜色为黑色
self.imageview.layer.shadowOpacity = 0.3; // 设置阴影的不透明度
self.imageview.image = [self createNonInterpolatedUIImageFormCIImage:ciImage size: SCREENWIDGH-20];
}
//2.生成高清二维码方法
- (UIImage *)createNonInterpolatedUIImageFormCIImage:(CIImage *)ciImage size:(CGFloat)widthAndHeight
{
CGRect extentRect = CGRectIntegral(ciImage.extent);
CGFloat scale = MIN(widthAndHeight / CGRectGetWidth(extentRect), widthAndHeight / CGRectGetHeight(extentRect));
// 1.创建bitmap;
size_t width = CGRectGetWidth(extentRect) * scale;
size_t height = CGRectGetHeight(extentRect) * scale;
CGColorSpaceRef cs = CGColorSpaceCreateDeviceGray();
CGContextRef bitmapRef = CGBitmapContextCreate(nil, width, height, 8, 0, cs, (CGBitmapInfo)kCGImageAlphaNone);
CIContext *context = [CIContext contextWithOptions:nil];
CGImageRef bitmapImage = [context createCGImage:ciImage fromRect:extentRect];
CGContextSetInterpolationQuality(bitmapRef, kCGInterpolationNone);
CGContextScaleCTM(bitmapRef, scale, scale);
CGContextDrawImage(bitmapRef, extentRect, bitmapImage);
// 保存bitmap到图片
CGImageRef scaledImage = CGBitmapContextCreateImage(bitmapRef);
CGContextRelease(bitmapRef);
CGImageRelease(bitmapImage);
//return [UIImage imageWithCGImage:scaledImage]; // 黑白图片
UIImage *newImage = [UIImage imageWithCGImage:scaledImage];
return [self imageBlackToTransparent:newImage withRed:200.0f andGreen:70.0f andBlue:189.0f];
}
//3.设置图片透明度
void ProviderReleaseData (void *info, const void *data, size_t size){
free((void*)data);
}
- (UIImage*)imageBlackToTransparent:(UIImage*)image withRed:(CGFloat)red andGreen:(CGFloat)green andBlue:(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);
CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
CGContextRef context = CGBitmapContextCreate(rgbImageBuf, imageWidth, imageHeight, 8, bytesPerRow, colorSpace,
kCGBitmapByteOrder32Little | kCGImageAlphaNoneSkipLast);
CGContextDrawImage(context, CGRectMake(0, 0, imageWidth, imageHeight), image.CGImage);
// 遍历像素
int pixelNum = imageWidth * imageHeight;
uint32_t* pCurPtr = rgbImageBuf;
for (int i = 0; i < pixelNum; i++, pCurPtr++){
if ((*pCurPtr & 0xFFFFFF00) < 0x99999900) // 将白色变成透明
{
// 改成下面的代码，会将图片转成想要的颜色
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;
}
}
// 输出图片
CGDataProviderRef dataProvider = CGDataProviderCreateWithData(NULL, rgbImageBuf, bytesPerRow * imageHeight, ProviderReleaseData);
CGImageRef imageRef = CGImageCreate(imageWidth, imageHeight, 8, 32, bytesPerRow, colorSpace,
kCGImageAlphaLast | kCGBitmapByteOrder32Little, dataProvider,
NULL, true, kCGRenderingIntentDefault);
CGDataProviderRelease(dataProvider);
UIImage* resultUIImage = [UIImage imageWithCGImage:imageRef];
// 清理空间
CGImageRelease(imageRef);
CGContextRelease(context);
CGColorSpaceRelease(colorSpace);
return resultUIImage;
}
注如果对二维码的清晰度要求不高可使用下面代码
-(UIImage *)generaterSmallErcode{
// 1.实例化二维码滤镜
CIFilter *filter = [CIFilter filterWithName:@"CIQRCodeGenerator"];
// 2.恢复滤镜的默认属性 (因为滤镜有可能保存上一次的属性)
[filter setDefaults];
// 3.将字符串转换成NSdata
NSData *data = [@"二维码数据" dataUsingEncoding:NSUTF8StringEncoding];
// 4.通过KVO设置滤镜, 传入data, 将来滤镜就知道要通过传入的数据生成二维码
[filter setValue:data forKey:@"inputMessage"];
// 5.生成二维码
CIImage *outputImage = [filter outputImage];
UIImage *image = [UIImage imageWithCIImage:outputImage];
return image;
}
@end