Use Libqrencode library to make QR code Electronic Business card--ios version

1.:

Click the Generate button to display the QR code:

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After using sweep, get the following interface:

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2, Libqrencode Library:

Libqrencode is a cross-platform C language library written by a Japanese (Kentaro Fukuchi) to generate a QR code.
The official website is here, GitHub is here.
My favorite is this " written in C, cross-platform, functional single, easy to use " Library!
iOS in OBJC using C + + library Super Convenient, Android, a little trouble.

3, OBJC to Libqrencode Packaging:

The online search for the Qrcodegenerator class, implemented by Andrew Kopanev.
Very simply, just a method, given a string, returns a uiimage representation of a two-dimensional code image:

@interface qrcodegenerator:nsobject+ (UIImage *) qrimageforstring: (NSString *) string imageSize: (cgfloat) size; @end

Take a look at the key points of implementation:

+  (uiimage *) qrimageforstring: (nsstring *) String imagesize: (cgfloat) size {     if  (![ String length])  {        return nil;     }    //First step: Generate QRCode from UTF string, call the core function of Libqrencode     QRcode  *code = qrcode_encodestring ([String utf8string], 0, qr_eclevel_l, qr_mode_8,  1);    if  (!code)  {        return  nil;    }    //Second Step:create context     Cgcolorspaceref colorspace = cgcolorspacecreatedevicergb ();     cgcontextref  ctx = cgbitmapcontextcreate (0, size, size, 8, size * 4,  colorspace, kcgimagealphapremultipliedlast);     //Step Three: space transformation     Because the coordinate system of coregraphic is the right hand, the origin is     //in the lower left corner and the coordinate system in Uikit is the left hand system, the origin is in the upper left corner     // Therefore, after the following translation and scaling matrix operation, the UIImage is based on the left-hand corner of the left-handed line     CGAffineTransform translateTransform  = cgaffinetransformmaketranslation (0, -size);    cgaffinetransform  Scaletransform = cgaffinetransformmakescale (1, -1);     CGCONTEXTCONCATCTM ( Ctx, cgaffinetransformconcat (Translatetransform, scaletransform));     // Fourth step: Generate a two-dimensional code bitmap in the context of the image     // draw QR on this context         [QRCodeGenerator drawQRCode:code context:ctx size:size];     //Fifth Step:get image    cgimageref qrcgimage =  Cgbitmapcontextcreateimage (CTX);    uiimage * qrimage = [uiimage  imagewithcgimage:qrcgimage];     //Sixth step: Some releases    cgcontextrelease (CTX);     Cgimagerelease (Qrcgimage);     cgcolorspacerelease (colorspace);     Qrcode_free (code);     return qrimage;}

The main point is to pay attention to the third step, spatial transformation. transform the right-hand lower left corner to the upper left-hand corner of the system.

4. vcard Format:

Baidu Encyclopedia detailed description of the format of the vcard

Let's look at a common format using a function (see code comments ):

-(nsstring*)  getvcardstring{    nsmutablestring* ret = [[ Nsmutablestring alloc]init];    //vcard specification:     //1, beginning with Begin:vcard, End:vcard End     [ret appendstring:@ "begin:vcard \n"];    //2, Define a lot of keywords, please refer to Baidu Encyclopedia, this example used some of the more important keywords     //3, general format for  key : value, such as the following   fn: Aoyama minded Xianfeng line     [ret appendstring:@ "fn:"];    [ret  appendstring:@ "Castle Peak minded Xianfeng"];    [ret appendstring:@ "\ n"];    // 4, if there are sub-projects, use; separate, for example, the following Tel tel contains mobile phone cell and company phone work or home phone home, but also can be voice,fax and so on     [ret  appendstring:@ "TEL; CELL; VOICE: "];    [ret appendstring: @" 13900000000 "];    [ret  appendstring:@ "\ n"];    [ret appendstring:@ "TEL; work; VOICE: "];    [RET&Nbsp;appendstring:@ "021-12345678"];    [ret appendstring:@ "\ n"];     //Ibid, email also has sub-project     [ret appendstring:@ "email; Pref;internet: "];    [ret appendstring:@" [email protected] "];     [ret appendstring:@ "\ n"];    //5, a pit for a couple of hours. Note: When you see the code, you finally add the "\ n" character, right.     //    because   if the line is longer than 75 characters, you must have a branch     //     so   during insurance, each item adds a newline character     [ret appendstring:@ "URL:"];     [ret appendstring:@ "HTTPS://GITHUB.COM/JACKYBLF"];    [ret appendstring:@ " \ n "];    //6, custom keywords, start with x, and of course also compatible with your phone's phone store program, otherwise your mobile phone storage program does not recognize your customized content      /*    nsstring* qq = @ "47178234";    [ret  appendstring:@ "X-QQ:"];    [ret appendstring:qq];    [ret appendstring:@ "\ n"];    */    [ ret appendstring:@ "End:vcard"];    return ret;}

5, the creation of two-dimensional code in iOS Electronic Business card:

-(Ibaction) Forevent: (Uievent *) Event {//NOTE: Must be a square uiimageview, two-dimensional code is basically square bar self.imageView.image = [Qrcodegenerator Qrimageforstring:[self getvcardstring] imageSize:self.imageView.bounds.size.width];}

This article from "with the wind and the green shirt minded Xianfeng line" blog, reprint please contact the author!

Use Libqrencode library to make QR code Electronic Business card--ios version