一、二维码简介
从iOS7开始集成了二维码的生成和读取功能
此前被广泛使用的zbarsdk目前不支持64位处理器
二、生成二维码
1.生成二维码的步骤：
- 导入CoreImage框架
- 通过滤镜CIFilter生成二维码
2.二维码的内容(传统的条形码只能放数字):
- 纯文本
- 名片
- URL
3.生成二维码的代码实现
#import "ViewController.h"
#import <CoreImage/CoreImage.h>
@interface ViewController ()
@property (weak, nonatomic) IBOutlet UIImageView *imageView;
@end
@implementation ViewController
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
// 1.创建过滤器
CIFilter *filter = [CIFilter filterWithName:@"CIQRCodeGenerator"];
// 2.恢复默认
[filter setDefaults];
// 3.给过滤器添加数据(正则表达式/账号和密码)
NSString *dataString = @"http://www.520it.com";
NSData *data = [dataString dataUsingEncoding:NSUTF8StringEncoding];
[filter setValue:data forKeyPath:@"inputMessage"];
// 4.获取输出的二维码
CIImage *outputImage = [filter outputImage];
// 5.显示二维码
self.imageView.image = [self createNonInterpolatedUIImageFormCIImage:outputImage withSize:200];
}
/**
* 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
三、扫描二维码
1.读取二维码需要导入AVFoundation框架
2.利用摄像头识别二维码中的内容（模拟器不行）
- 输入（摄像头）
- 由会话将摄像头采集到的二维码图像转换成字符串数据
- 输出（数据）
- 由预览图层显示扫描场景
3.扫描二维码的代码
#import "ViewController.h"
#import <AVFoundation/AVFoundation.h>
@interface ViewController () <AVCaptureMetadataOutputObjectsDelegate>
@property (nonatomic, weak) AVCaptureSession *session;
@property (nonatomic, weak) AVCaptureVideoPreviewLayer *layer;
@end
@implementation ViewController
- (void)viewDidLoad {
[super viewDidLoad];
}
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
// 1.创建捕捉会话
AVCaptureSession *session = [[AVCaptureSession alloc] init];
self.session = session;
// 2.添加输入设备(数据从摄像头输入)
AVCaptureDevice *device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
AVCaptureDeviceInput *input = [AVCaptureDeviceInput deviceInputWithDevice:device error:nil];
[session addInput:input];
// 3.添加输出数据(示例对象-->类对象-->元类对象-->根元类对象)
AVCaptureMetadataOutput *output = [[AVCaptureMetadataOutput alloc] init];
[output setMetadataObjectsDelegate:self queue:dispatch_get_main_queue()];
[session addOutput:output];
// 3.1.设置输入元数据的类型(类型是二维码数据)
[output setMetadataObjectTypes:[output availableMetadataObjectTypes]];
// 4.添加扫描图层
AVCaptureVideoPreviewLayer *layer = [AVCaptureVideoPreviewLayer layerWithSession:session];
layer.frame = self.view.bounds;
[self.view.layer addSublayer:layer];
self.layer = layer;
// 5.开始扫描
[session startRunning];
}
#pragma mark - 实现output的回调方法
// 当扫描到数据时就会执行该方法
- (void)captureOutput:(AVCaptureOutput *)captureOutput didOutputMetadataObjects:(NSArray *)metadataObjects fromConnection:(AVCaptureConnection *)connection
{
if (metadataObjects.count > 0) {
AVMetadataMachineReadableCodeObject *object = [metadataObjects lastObject];
// NSLog(@"%@--%zd", object.type,metadataObjects.count);
// object.type
// *****************
NSLog(@"----------");
NSLog(@"%@",object.stringValue);
NSLog(@"----------");
// 这段二维码的作用是是解决gbk乱码的作用
// NSString *result=object.stringValue;//返回的扫描结果
// NSData *data=[object.stringValue dataUsingEncoding:NSUTF8StringEncoding];
// NSStringEncoding enc = CFStringConvertEncodingToNSStringEncoding(kCFStringEncodingGB_18030_2000);
// NSString *retStr = [[NSString alloc] initWithData:data encoding:enc];//如果中文是utf-8编码转gbk结果为空(还没搞明白)
// if (retStr)//如果扫描中文乱码则需要处理，否则不处理
// {
// NSInteger max = [object.stringValue length];
// char *nbytes = malloc(max + 1);
// for ( int i = 0; i < max; i++)
// {
// unichar ch = [object.stringValue characterAtIndex: i];
// nbytes[i] = (char) ch;
// }
// nbytes[max] = '\0';
// result=[NSString stringWithCString: nbytes
// encoding: enc];
// NSLog(@"成功的啦%@",result);
// }
// **************
// 停止扫描
[self.session stopRunning];
// 将预览图层移除
[self.layer removeFromSuperlayer];
} else {
NSLog(@"没有扫描到数据");
}
}
@end
四、识别二维码
CIImage* image;
NSArray* array =[_QRCodeDector featuresInImage:image];
for (CIFeature* feature in array) {
if([feature isKindOfClass:[CIQRCodeFeature class]]) {
CIQRCodeFeature* QRCodeFeature = (CIQRCodeFeature*)feature;
[[[UIAlertView alloc] initWithTitle:@"二维码" message:QRCodeFeature.messageString delegate:nil cancelButtonTitle:@"确定" otherButtonTitles: nil] show];
return;
}
}
