iOS 根据链接生成二维码图片

一、.h文件

//

//  CIImage+Extension.h

//  根据链接生成生成二维码

//

//  Created by zsl on 17/12/25.

//  Copyright © 2017年 zsl. All rights reserved.

//

#import

#import

@interfaceCIImage (Extension)

/**

 根据CIImage生成指定大小的UIImage

 @param size 尺寸

 @return 图片对象

 */

- (UIImage*)createNonInterpolatedWithSize:(CGFloat)size;

@end

二、.m文件

//

//  CIImage+Extension.m

//  根据链接生成生成二维码

//

//  Created by zsl on 17/12/25.

//  Copyright © 2017年 zsl. All rights reserved.

//

#import "CIImage+Extension.h"

@implementationCIImage (Extension)

/**

 *  根据CIImage生成指定大小的UIImage

 *

 *  @param image CIImage

 *  @param size  图片宽度

 */

- (UIImage*)createNonInterpolatedWithSize:(CGFloat)size {

    CGRect extent = CGRectIntegral(self.extent);

    CGFloatscale =MIN(size/CGRectGetWidth(extent), size/CGRectGetHeight(extent));

    // 1.创建bitmap;

    size_twidth =CGRectGetWidth(extent) * scale;

    size_theight =CGRectGetHeight(extent) * scale;

    CGColorSpaceRef cs = CGColorSpaceCreateDeviceGray();

    CGContextRef bitmapRef = CGBitmapContextCreate(nil, width, height, 8, 0, cs, (CGBitmapInfo)kCGImageAlphaNone);

    CIContext *context = [CIContext contextWithOptions:nil];

    CGImageRefbitmapImage = [contextcreateCGImage:selffromRect: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];

}

@end

三、引用方式：在调用界面进行引用上面拓展类的头文件#import "CIImage+Extension.h"

    // 1.创建滤镜对象

    CIFilter *filter = [CIFilter filterWithName:@"CIQRCodeGenerator"];

    // 2.恢复默认设置

    [filter setDefaults];

    //3.链接字符串

    NSString *str = @"https://www.jianshu.com/u/4c669da2ffa3";

    // 4.将链接字符串转data格式

    NSData *strData = [str dataUsingEncoding:NSUTF8StringEncoding];

    [filter setValue:strData forKeyPath:@"inputMessage"];

    // 5.生成二维码

    CIImage*outputImage = [filter outputImage];

    UIImageView *imageView = [[UIImageView alloc]init];

     // 6.将二维码进行展示

    imageView = [outputImage createNonInterpolatedWithSize:80];