#import <CoreImage/CoreImage.h>
/** 生成二維碼*/
- (void)set2DimensionalBarCode:(UIImageView *)imgView
{
// 1.實(shí)例化二維碼濾鏡
CIFilter *filter = [CIFilter filterWithName:@"CIQRCodeGenerator"];
// 2.恢復(fù)濾鏡的默認(rèn)屬性
[filter setDefaults];
// 3.二維碼信息
//NSString *str = @"哎呀我去"; // 展示一串文字
NSString *str = @"http://www.baidu.com"; // 直接打開網(wǎng)頁(yè)
// 4.將字符串轉(zhuǎn)成二進(jìn)制數(shù)據(jù)
NSData *data = [str dataUsingEncoding:NSUTF8StringEncoding];
// 5.通過(guò)KVC設(shè)置濾鏡inputMessage數(shù)據(jù)
[filter setValue:data forKey:@"inputMessage"];
// 6.獲取濾鏡輸出的圖像
CIImage *outputImage = [filter outputImage];
// 7.將CIImage轉(zhuǎn)成UIImage
//系統(tǒng)默認(rèn)獲取到的二維碼圖片不太清晰,可以利用這個(gè)方法,獲取指定大小(傳入的size參數(shù)值)的二維碼圖片
UIImage *image = [self createNonInterpolatedUIImageFormCIImage:outputImage withSize:200];
// 8.展示二維碼
imgView.image = image;
}
/**
*? 根據(jù)CIImage生成指定大小的UIImage
*
*? @param image CIImage
*? @param size? 圖片寬度
*/
- (UIImage *)createNonInterpolatedUIImageFormCIImage:(CIImage *)image withSize:(CGFloat) size
{
CGRect extent = CGRectIntegral(image.extent);
CGFloat scale = MIN(size/CGRectGetWidth(extent), size/CGRectGetHeight(extent));
// 1.創(chuàng)建bitmap;
size_t width = CGRectGetWidth(extent) * scale;
size_t height = CGRectGetHeight(extent) * scale;
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到圖片
CGImageRef scaledImage = CGBitmapContextCreateImage(bitmapRef);
CGContextRelease(bitmapRef);
CGImageRelease(bitmapImage);
return [UIImage imageWithCGImage:scaledImage];
}
