iOS development Swift uses Cifilter to generate a two-dimensional code picture (QRCode)

Cifilter provides a wide variety of filters, where ciqrcodegenerator can be used to generate two-dimensional code. The following example shows how to generate a two-dimensional code picture of a string (a link is also a string), while also supporting the placement of personalized icons in the middle of a two-dimensional code.

The effect chart is as follows:

The code is as follows

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Import Uikit Class Viewcontroller:uiviewcontroller { Override Func Viewdidload () { Super.viewdidload () Two-dimensional code picture with no picture Let ImageViewIcon1 = Uiimageview (Frame:cgrectmake (20, 20, 150, 150)) Imageviewicon1.image = createqrforstring ("Http://www.111cn.net", Qrimagename: "") Self.view.addSubview (ImageViewIcon1) Two-dimensional code picture with pictures Let ImageViewIcon2 = Uiimageview (Frame:cgrectmake (200, 20, 150, 150)) Imageviewicon2.image = createqrforstring ("Http://www.111cn.net", Qrimagename: "logo") Self.view.addSubview (ImageViewIcon2) } Create a two-dimensional code picture Func createqrforstring (qrstring:string, qrimagename:string?)-> UIImage? { If let sureqrstring = qrstring { Let StringData = sureqrstring.datausingencoding (nsutf8stringencoding, Allowlossyconversion:false) Create a two-dimensional code filter Let Qrfilter = Cifilter (name: "Ciqrcodegenerator")! Qrfilter.setvalue (StringData, Forkey: "InputMessage") Qrfilter.setvalue ("H", Forkey: "Inputcorrectionlevel") Let Qrciimage = Qrfilter.outputimage Create a color filter, black and white Let Colorfilter = Cifilter (name: "Cifalsecolor")! Colorfilter.setdefaults () Colorfilter.setvalue (Qrciimage, Forkey: "Inputimage") Colorfilter.setvalue (Cicolor (red:0, green:0, blue:0), Forkey: "InputColor0") Colorfilter.setvalue (Cicolor (red:1, Green:1, blue:1), Forkey: "InputColor1") Returns two-dimensional code image Let Codeimage = UIImage (ciimage:colorfilter.outputimage! . Imagebyapplyingtransform (Cgaffinetransformmakescale (5, 5)) Normally, two-dimensional codes are custom-coded, with images in the middle that want to express meaning. If Let Iconimage = UIImage (named:qrimagename!) { Let rect = CGRectMake (0, 0, codeImage.size.width, codeImage.size.height) Uigraphicsbeginimagecontext (Rect.size) Codeimage.drawinrect (Rect) Let avatarsize = Cgsizemake (Rect.size.width * 0.25, Rect.size.height * 0.25) Let x = (rect.width-avatarsize.width) * 0.5 Let y = (rect.height-avatarsize.height) * 0.5 Iconimage.drawinrect (CGRectMake (x, Y, Avatarsize.width, avatarsize.height)) Let Resultimage = Uigraphicsgetimagefromcurrentimagecontext () Uigraphicsendimagecontext () Return Resultimage } Return Codeimage } return Nil } Override Func didreceivememorywarning () { Super.didreceivememorywarning () } }