ios 有没有一种方法来生成iOS上的QR码图片
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Is there a way to generate QR code image on iOS
提问by user1561181
Is there a standard way to generate a QR code and attach it to a mail item from iOS client app (no server code)?
是否有一种标准方法可以生成二维码并将其附加到来自 iOS 客户端应用程序的邮件项目（无服务器代码）？
回答by quarac
Since iOS 7, you can use a Core Image filter to generate QR images. See the final tip here:
从 iOS 7 开始，您可以使用 Core Image 过滤器来生成 QR 图像。请参阅此处的最后提示：
- (CIImage *)createQRForString:(NSString *)qrString {
NSData *stringData = [qrString dataUsingEncoding: NSISOLatin1StringEncoding];
CIFilter *qrFilter = [CIFilter filterWithName:@"CIQRCodeGenerator"];
[qrFilter setValue:stringData forKey:@"inputMessage"];
return qrFilter.outputImage;
}
回答by Mike Demidov
For Obj-C version that perfectly works for me, I've mixed answers ??? and Teja Kumar Bethina:
对于完全适合我的 Obj-C 版本，我的答案不一？？？？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];
回答by ???
Using Swift 2
使用 Swift 2
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 3.0
斯威夫特 3.0
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)
}
Swift 4.2
斯威夫特 4.2
private func createQRFromString(str: String) -> CIImage? {
let stringData = str.data(using: .utf8)
let filter = CIFilter(name: "CIQRCodeGenerator")
filter?.setValue(stringData, forKey: "inputMessage")
filter?.setValue("H", forKey: "inputCorrectionLevel")
return filter?.outputImage
}
var qrCode: UIImage? {
if let img = createQRFromString(str: "Hello world program created by someone") {
let someImage = UIImage(
ciImage: img,
scale: 1.0,
orientation: UIImage.Orientation.down
)
return someImage
}
return nil
}
回答by Fred Truter
It has been a while since this question was asked and a number of almost perfect answers have been given already. However I had to tweak and combine several answers to get it working perfectly for AppleTV 4K, iPhone X and iPadPro using Xcode 9.2 in 2018. Here's the code if anyone needs it.
自从提出这个问题以来已经有一段时间了，并且已经给出了一些几乎完美的答案。然而，我不得不调整并结合几个答案，使其在 2018 年使用 Xcode 9.2 完美适用于 AppleTV 4K、iPhone X 和 iPadPro。如果有人需要，这里是代码。
@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
}
回答by Teja Kumar Bethina
Code to generate QR image in Swift 2.0.
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)
回答by ingaham
I have used the QR Code Encoderfor QR generation. It is very easy to use. There are some other option to generate, e.g this.
我使用QR Code Encoder生成 QR。这是非常容易使用。还有一些其他选项可以生成，例如this。
回答by Avivo
...which will let me generate links...
...这将让我生成链接...
First, you need to find a short link service, e.g. bit.lyor goo.by, to make a long link shorter and thus reduce QR Code size.
首先，您需要找到一个短链接服务，例如bit.ly或goo.by，将长链接缩短，从而减少二维码大小。
To perform this task automatically you will have to use some web service.
要自动执行此任务，您必须使用某些 Web 服务。
...then generate a QR code...
...然后生成一个二维码...
ZXingis a popular open source QR Code generator also available for iOS
ZXing是一个流行的开源二维码生成器，也可用于 iOS
回答by Sharukh Mastan
If you don't mind using public api, here is an easy 10 seconds method. http://goqr.me/api
如果您不介意使用公共 api，这里有一个简单的 10 秒方法。http://goqr.me/api
Just fill in the data parameter, and load the image from the response. Cheers.
只需填写数据参数，然后从响应中加载图像。干杯。
回答by gorkem
I created a NSString Category for Obj-C, taking Mike Demidov awesome answer
我为 Obj-C 创建了一个 NSString 类别，采用了 Mike Demidov 很棒的答案
NString+GGQRCode.h
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
NString+GGQRCode.m
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
