二维码之qrencode生成(带logo)

从github下载的qrencode没有QRCodeGenerator文件,需要引入

//
// QR Code Generator - generates UIImage from NSString
//
// Copyright (C) 2012 http://moqod.com Andrew Kopanev <andrew@moqod.com>
//
// Permission is hereby granted, free of charge, to any person obtaining a copy 
// of this software and associated documentation files (the "Software"), to deal 
// in the Software without restriction, including without limitation the rights 
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies 
// of the Software, and to permit persons to whom the Software is furnished to do so, 
// subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in all 
// copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, 
// INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR 
// PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE
// FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR 
// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER 
// DEALINGS IN THE SOFTWARE.
//

#import <Foundation/Foundation.h>
#import <UIKit/UIKit.h>

@interface QRCodeGenerator : NSObject

+ (UIImage *)qrImageForString:(NSString *)string imageSize:(CGFloat)size;

@end

//
// QR Code Generator - generates UIImage from NSString
//
// Copyright (C) 2012 http://moqod.com Andrew Kopanev <andrew@moqod.com>
//
// Permission is hereby granted, free of charge, to any person obtaining a copy 
// of this software and associated documentation files (the "Software"), to deal 
// in the Software without restriction, including without limitation the rights 
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies 
// of the Software, and to permit persons to whom the Software is furnished to do so, 
// subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in all 
// copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, 
// INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR 
// PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE
// FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR 
// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER 
// DEALINGS IN THE SOFTWARE.
//

#import "QRCodeGenerator.h"
#import "qrencode.h"

enum {
    qr_margin = 3
};

@implementation QRCodeGenerator

+ (void)drawQRCode:(QRcode *)code context:(CGContextRef)ctx size:(CGFloat)size {
    unsigned char *data = 0;
    int width;
    data = code->data;
    width = code->width;
    float zoom = (double)size / (code->width + 2.0 * qr_margin);
    CGRect rectDraw = CGRectMake(0, 0, zoom, zoom);
    
    // draw
    CGContextSetFillColor(ctx, CGColorGetComponents([UIColor blackColor].CGColor));
    for(int i = 0; i < width; ++i) {
        for(int j = 0; j < width; ++j) {
            if(*data & 1) {
                rectDraw.origin = CGPointMake((j + qr_margin) * zoom,(i + qr_margin) * zoom);
                CGContextAddRect(ctx, rectDraw);
            }
            ++data;
        }
    }
    CGContextFillPath(ctx);
}

+ (UIImage *)qrImageForString:(NSString *)string imageSize:(CGFloat)size {
    if (![string length]) {
        return nil;
    }
    
    QRcode *code = QRcode_encodeString([string UTF8String], 0, QR_ECLEVEL_L, QR_MODE_8, 1);
    if (!code) {
        return nil;
    }
    
    // create context
    CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
    CGContextRef ctx = CGBitmapContextCreate(0, size, size, 8, size * 4, colorSpace, kCGImageAlphaPremultipliedLast);
    
    CGAffineTransform translateTransform = CGAffineTransformMakeTranslation(0, -size);
    CGAffineTransform scaleTransform = CGAffineTransformMakeScale(1, -1);
    CGContextConcatCTM(ctx, CGAffineTransformConcat(translateTransform, scaleTransform));
    
    // draw QR on this context    
    [QRCodeGenerator drawQRCode:code context:ctx size:size];
    
    // get image
    CGImageRef qrCGImage = CGBitmapContextCreateImage(ctx);
    UIImage * qrImage = [UIImage imageWithCGImage:qrCGImage];
    
    // some releases
    CGContextRelease(ctx);
    CGImageRelease(qrCGImage);
    CGColorSpaceRelease(colorSpace);
    QRcode_free(code);
    
    return qrImage;
}

@end

//
//  ViewController.m
//  qRenCode
//
//  Created by City--Online on 15/6/9.
//  Copyright (c) 2015年 CYW. All rights reserved.
//

#import "ViewController.h"
#import "QRCodeGenerator.h"
@interface ViewController ()
@property(nonatomic,strong) UITextField *textField;
@property(nonatomic,strong) UIButton *btn;
@property(nonatomic,strong) UIImageView *imgView;
@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    _textField=[[UITextField alloc]initWithFrame:CGRectMake(10, 100, 300, 40)];
    _textField.borderStyle=UITextBorderStyleLine;
    [self.view addSubview:_textField];
    
    _btn=[UIButton buttonWithType:UIButtonTypeSystem];
    [_btn setTitle:@"生成" forState:UIControlStateNormal];
    [_btn setTitleColor:[UIColor redColor] forState:UIControlStateNormal];
    _btn.frame=CGRectMake(20, 150, 100, 40);
    [_btn addTarget:self action:@selector(btnClick:) forControlEvents:UIControlEventTouchUpInside];
    [self.view addSubview:_btn];
    
    _imgView=[[UIImageView alloc]initWithFrame:CGRectMake(20, 200, 250, 250)];
//    _imgView.backgroundColor=[UIColor blackColor];
    [self.view addSubview:_imgView];
}
-(void)btnClick:(id)sender
{
    _imgView.image = [QRCodeGenerator qrImageForString:_textField.text imageSize:_imgView.bounds.size.width];

}
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
    [_textField resignFirstResponder];
}
- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

@end

有时候想在二维码中间带个Logo,犹豫二维码有容错率，所以可以直接将图片添加上去

-(void)btnClick:(id)sender
{
    _imgView.image = [QRCodeGenerator qrImageForString:_textField.text imageSize:_imgView.bounds.size.width];
    UIImageView *img=[[UIImageView alloc]initWithImage:[UIImage imageNamed:@"1.jpg"]];
    img.frame=CGRectMake(_imgView.bounds.size.width*3/7, _imgView.bounds.size.height*3/7, _imgView.bounds.size.width/7, _imgView.bounds.size.height/7);
    img.backgroundColor=[UIColor redColor];
    [_imgView addSubview:img];

}