//
//  ViewController.m
//  CX 二维码生成
//
//  Created by ma c on 16/4/12.
//  Copyright ? 2016年 bjsxt. All rights reserved.
//

#import "ViewController.h"
#import <CoreImage/CoreImage.h>
@interface ViewController ()

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    
}

- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event{
    
    //创建过滤器
    CIFilter * filter = [CIFilter filterWithName:@"CIQRCodeGenerator"];
    //恢复默认设置
    [filter setDefaults];
    //给过滤器添加数据
    NSString * str = @"旭宝爱吃鱼";//这里的文本可以是URL
    NSData * data = http://www.mamicode.com/[str dataUsingEncoding:NSUTF8StringEncoding];"inputMessage"];
    //输出获取的二维码
     CIImage * image = [filter outputImage];
    //显示二维码
    UIImageView * imageView = [[UIImageView alloc]initWithFrame:CGRectMake(20, 20, 100, 100)];
    imageView.image = [UIImage imageWithCIImage:image];
    [self.view addSubview:imageView];
    
}

@end

//
//  ViewController.m
//  CX 二维码生成
//
//  Created by ma c on 16/4/12.
//  Copyright ? 2016年 bjsxt. All rights reserved.
//

#import "ViewController.h"
#import <CoreImage/CoreImage.h>
@interface ViewController ()

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    
}

- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event{
    
    //创建过滤器
    CIFilter * filter = [CIFilter filterWithName:@"CIQRCodeGenerator"];
    //恢复默认设置
    [filter setDefaults];
    //给过滤器添加数据
    NSString * str = @"旭宝爱吃鱼";//这里的文本可以是URL
    NSData * data = http://www.mamicode.com/[str dataUsingEncoding:NSUTF8StringEncoding];"inputMessage"];
    //输出获取的二维码
     CIImage * image = [filter outputImage];
    //显示二维码
    UIImageView * imageView = [[UIImageView alloc]initWithFrame:CGRectMake(20, 20, 100, 100)];
    imageView.image = [self createNonInterpolatedUIImageFormCIImage:image withSize:200];
    [self.view addSubview:imageView];

}

/**
 *  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
{
    
    CGRect extent = CGRectIntegral(image.extent);
    CGFloat scale = MIN(size/CGRectGetWidth(extent), size/CGRectGetHeight(extent));
    
    // 1.创建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到图片
    CGImageRef scaledImage = CGBitmapContextCreateImage(bitmapRef);
    CGContextRelease(bitmapRef);
    CGImageRelease(bitmapImage);
    return [UIImage imageWithCGImage:scaledImage];
}
@end