iOS 生成二维码

#import <UIKit/UIKit.h>

@interface AppDelegate : UIResponder <UIApplicationDelegate>

@property (strong, nonatomic) UIWindow *window;


@end

#import "AppDelegate.h"
#import "RootViewController.h"
@interface AppDelegate ()

@end

@implementation AppDelegate


- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
    // Override point for customization after application launch.
    self.window.backgroundColor = [UIColor whiteColor];
    
    self.window.rootViewController = [[RootViewController alloc] init];
    
    [self.window makeKeyAndVisible];
    return YES;
}


@end

#import <UIKit/UIKit.h>

@interface RootViewController : UIViewController

@end

#import "RootViewController.h"

@interface RootViewController ()

@property (nonatomic , strong) UIImageView *imgView;

@end

@implementation RootViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    
    CGFloat width = 200;
    CGFloat height = 200;
    self.imgView = [[UIImageView alloc] initWithFrame:CGRectMake(self.view.center.x - width/2.0, self.view.center.y - height/2.0, width, height)];
    [self.view addSubview:self.imgView];
    
    [self productImageView];
}

- (void)productImageView{
    
    CIFilter *filter = [CIFilter filterWithName:@"CIQRCodeGenerator"];
    
    [filter setDefaults];
    NSString *string = @"想择一人，一城；终老";
    NSData *data = [string dataUsingEncoding:NSUTF8StringEncoding];
    [filter setValue:data forKey:@"inputMessage"];
    CIImage *outputImage = [filter outputImage];
    
    self.imgView.image = [self createUIImageFromCIImage:outputImage withSize:100.0];
}

- (UIImage *)createUIImageFromCIImage:(CIImage *)image withSize:(CGFloat)size{
    CGRect extent = CGRectIntegral(image.extent);
    CGFloat scale = MIN(size/CGRectGetWidth(extent), size/CGRectGetHeight(extent));
    
    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);
    
    CGImageRef scaleImage = CGBitmapContextCreateImage(bitmapRef);
    
    CGContextRelease(bitmapRef);
    
    CGImageRelease(bitmapImage);
    
    return [UIImage imageWithCGImage:scaleImage];
}



@end