有没有办法在iOS上生成QR码图像

时间:2012-08-21 08:41:20

标签: ios qr-code

是否有标准的方法来生成QR码并将其附加到iOS客户端应用程序中的邮件项目(无服务器代码)?

9 个答案:

答案 0 :(得分:83)

从iOS 7开始,您可以使用Core Image过滤器生成QR图像。见the final tip here

- (CIImage *)createQRForString:(NSString *)qrString {
    NSData *stringData = [qrString dataUsingEncoding: NSISOLatin1StringEncoding];

    CIFilter *qrFilter = [CIFilter filterWithName:@"CIQRCodeGenerator"];
    [qrFilter setValue:stringData forKey:@"inputMessage"];

    return qrFilter.outputImage;
}

答案 1 :(得分:16)

对于对我来说非常有用的Obj-C版本,我混合了答案和Teja Kumar Bethina:

NSString *qrString = @"My string to encode";
NSData *stringData = [qrString dataUsingEncoding: NSUTF8StringEncoding];

CIFilter *qrFilter = [CIFilter filterWithName:@"CIQRCodeGenerator"];
[qrFilter setValue:stringData forKey:@"inputMessage"];
[qrFilter setValue:@"H" forKey:@"inputCorrectionLevel"];

CIImage *qrImage = qrFilter.outputImage;
float scaleX = self.qrImageView.frame.size.width / qrImage.extent.size.width;
float scaleY = self.qrImageView.frame.size.height / qrImage.extent.size.height;

qrImage = [qrImage imageByApplyingTransform:CGAffineTransformMakeScale(scaleX, scaleY)];

self.qrImageView.image = [UIImage imageWithCIImage:qrImage
                                             scale:[UIScreen mainScreen].scale
                                       orientation:UIImageOrientationUp];

答案 2 :(得分:13)

使用Swift 2

canvas {

   border: 1px solid #000000;
   position:        relative;
   left:               500px; (Play with this # to position horizontally)
}

enter image description here

Swift 3.0

import UIKit
import CoreImage

func createQRFromString(str: String) -> CIImage? {
    let stringData = str.dataUsingEncoding(NSUTF8StringEncoding)

    let filter = CIFilter(name: "CIQRCodeGenerator")

    filter?.setValue(stringData, forKey: "inputMessage")

    filter?.setValue("H", forKey: "inputCorrectionLevel")

    return filter?.outputImage
}

if let img = createQRFromString("Hello world program created by someone") {
    let somImage = UIImage(CIImage: img, scale: 1.0, orientation: UIImageOrientation.Down)
}

Swift 4.2

import UIKit
import CoreImage

func createQRFromString(_ str: String) -> CIImage? {
        let stringData = str.data(using: String.Encoding.utf8)

        let filter = CIFilter(name: "CIQRCodeGenerator")

        filter?.setValue(stringData, forKey: "inputMessage")

        filter?.setValue("H", forKey: "inputCorrectionLevel")

        if let img = createQRFromString("Hello world program created by someone") {
            let somImage = UIImage(ciImage: img, scale: 1.0, orientation: UIImageOrientation.down)
        }

        return filter?.outputImage
    }

if let img = createQRFromString("Hello world program created by someone") {
            let somImage = UIImage(ciImage: img, scale: 1.0, orientation: UIImageOrientation.down)
        }

答案 3 :(得分:10)

自问这个问题以来已经有一段时间了,并且已经给出了一些近乎完美的答案。然而,我不得不调整并结合几个答案,以便在2018年使用Xcode 9.2对AppleTV 4K,iPhone X和iPadPro进行完美的工作。如果有人需要,可以使用代码。

@IBOutlet weak var qrCodeBox: UIImageView!

func createQRFromString(_ str: String, size: CGSize) -> UIImage {
    let stringData = str.data(using: .utf8)

  let qrFilter = CIFilter(name: "CIQRCodeGenerator")!
  qrFilter.setValue(stringData, forKey: "inputMessage")
  qrFilter.setValue("H", forKey: "inputCorrectionLevel")

  let minimalQRimage = qrFilter.outputImage!
  // NOTE that a QR code is always square, so minimalQRimage..width === .height
  let minimalSideLength = minimalQRimage.extent.width

  let smallestOutputExtent = (size.width < size.height) ? size.width : size.height
  let scaleFactor = smallestOutputExtent / minimalSideLength
  let scaledImage = minimalQRimage.transformed(
    by: CGAffineTransform(scaleX: scaleFactor, y: scaleFactor))

  return UIImage(ciImage: scaledImage, 
                 scale: UIScreen.main.scale, 
                 orientation: .up)
}

override func viewDidLoad() {
    super.viewDidLoad()
    let myQRimage = createQRFromString("https://www.apple.com", 
                      size: qrCodeBox.frame.size)
    qrCodeBox.image = myQRimage
}

答案 4 :(得分:4)

在Swift 2.0中生成QR图像的代码。

let reqStr = “string to convert as QR code”
let data = reqStr.dataUsingEncoding(NSISOLatin1StringEncoding, allowLossyConversion: false)

let filter = CIFilter(name: "CIQRCodeGenerator")
filter!.setValue(data, forKey: "inputMessage")

let qrImage:CIImage = filter!.outputImage!

//qrImageView is a IBOutlet of UIImageView        
let scaleX = qrImageView.frame.size.width / qrImage.extent.size.width
let scaleY = qrImageView.frame.size.height / qrImage.extent.size.height

let resultQrImage = qrImage.imageByApplyingTransform(CGAffineTransformMakeScale(scaleX, scaleY))
qrImageView.image = UIImage(CIImage: resultQrImage)

答案 5 :(得分:0)

我已使用QR Code Encoder进行QR生成。这是非常容易使用。还有一些其他选项可以生成,例如this

答案 6 :(得分:0)

  

...这将让我生成链接...

首先,您需要找到一个短链接服务,例如bit.lygoo.by,可缩短长链接,从而减少QR码的大小。

要自动执行此任务,您必须使用某些Web服务。

  

...然后生成QR码......

ZXing是一种流行的开源QR码生成器,也适用于iOS

答案 7 :(得分:0)

如果您不介意使用公共API,这是一个简单的10秒方法。 http://goqr.me/api

只需填写数据参数,然后从响应中加载图像。欢呼声。

答案 8 :(得分:0)

我为Obj-C创建了一个NSString类别,采用了Mike Demidov非常棒的答案

<强> NString + GGQRCode.h

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

@interface NSString (GGQRCode)

-(UIImage *)qrCodeImage:(CGFloat)width height:(CGFloat)height;
-(UIImage *)qrCodeImage:(CGFloat)width height:(CGFloat)height scale:(CGFloat)scale orientation:(UIImageOrientation)orientation;

@end

<强> NString + GGQRCode.m

#import "NSString+GGQRCode.h"

@implementation NSString (GGQRCode)

-(UIImage *)qrCodeImage:(CGFloat)width height:(CGFloat)height
{
    return [self qrCodeImage:width height:height scale:[UIScreen mainScreen].scale orientation:UIImageOrientationUp];
}

-(UIImage *)qrCodeImage:(CGFloat)width height:(CGFloat)height scale:(CGFloat)scale orientation:(UIImageOrientation)orientation
{
    NSData *stringData = [self dataUsingEncoding: NSUTF8StringEncoding];

    CIFilter *qrFilter = [CIFilter filterWithName:@"CIQRCodeGenerator"];
    [qrFilter setValue:stringData forKey:@"inputMessage"];
    [qrFilter setValue:@"H" forKey:@"inputCorrectionLevel"];

    CIImage *qrImage = qrFilter.outputImage;
    float scaleX = width / qrImage.extent.size.width;
    float scaleY = height / qrImage.extent.size.height;

    qrImage = [qrImage imageByApplyingTransform:CGAffineTransformMakeScale(scaleX, scaleY)];

    return [UIImage imageWithCIImage:qrImage scale:scale orientation:orientation];
}

@end