IOS note 061 two-dimensional code generation and scanning _ios

Now two-dimensional code everywhere, whether it is a kind of goods or a variety of gift certificates are not the figure of two-dimensional code. Mobile devices such as mobile phones and become a two-dimensional code of a good application platform, whether it is to generate two-dimensional code or sweep code two-dimensional code. This article from the generation of two-dimensional code, scanning two-dimensional code to expand the analysis, through the content of the two-dimensional code is easy to use.

First of all, the generation of two-dimensional code

Two-dimensional code can be stored in plain text, business cards or URLs

Second, the steps to generate two-dimensional code:

Import Coreimage Framework

To generate a two-dimensional code again through the filter cifilter

1. Create filter

2, restore the filter's default properties

3, set the content

4. Get output file

5, display two-dimensional code

Code implementation Coreimage

 Two-dimensional code generation
 //1, create filter
 cifilter *filter = [Cifilter filterwithname:@ "Ciqrcodegenerator"];
 2, restore the filter's default properties
 [Filter setdefaults];
 3, set content
 nsstring *str = @ "This is a two-dimensional code generation result";
 NSData *data = [str datausingencoding:nsutf8stringencoding];
 Use KVO to set properties
 [Filter Setvalue:data forkey:@ "InputMessage"];
 4, get output file
 ciimage *outputimage = [Filter outputimage];
 5, display two-dimensional code
 self.imageView.image = [UIImage imagewithciimage:outputimage];

The picture shown is not very clear, you can redraw the picture yourself

Re-build HD pictures: Online Search can be, the specific process can not care for the moment

/** * Generates the specified size uiimage * * @param image Ciimage * Based on Ciimage * @param size picture Width * * (uiimage *) Createnoninterpolateduiima
 Geformciimage: (ciimage *) image withsize: (cgfloat) Size {cgrect extent = cgrectintegral (image.extent);
 CGFloat scale = MIN (Size/cgrectgetwidth (extent), size/cgrectgetheight (extent));
 1. Create bitmap;
 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);
 2. Save bitmap to picture cgimageref Scaledimage = Cgbitmapcontextcreateimage (bitmapref);
 Cgcontextrelease (BITMAPREF); CgImagerelease (BitmapImage);
return [UIImage Imagewithcgimage:scaledimage]; }

There is the setting of content for the URL, if with the protocol header, will automatically open the Web page.

NSString *str = @http://www.baidu.com;

Must have a protocol header to open

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Scan two-dimensional code

Avfoundation Framework

The scanning process of two-dimensional code

1. Create capture session Avcapturesession

Add input device (data from camera input) Avcapturedevice Avcapturedeviceinput

2, add output data (Sample Object--> class object--> object--> root class object) Avcapturemetadataoutput

2.1. Set the type of input metadata (type is two-dimensional code data) setmetadataobjecttypes

3. Add Scan layer Avcapturevideopreviewlayer

4. Start Scanning startrunning

5, implement callback proxy method, get scan result captureoutput::

#import "ViewController.h" #import <AVFoundation/AVFoundation.h> @interface Viewcontroller () < avcapturemetadataoutputobjectsdelegate>/** Display Layer */@property (nonatomic, strong) Avcapturevideopreviewlayer *layer
;
/** Capture Session * * @property (nonatomic, strong) avcapturesession *session; @end @implementation Viewcontroller-(void) Touchesbegan: (Nsset *) touches withevent: (Uievent *) event {//two D code Scan//1, Chuang
 Build Capture Session Avcapturesession *session = [[Avcapturesession alloc] init];
 Self.session = session;
 2. Add input device (data from camera input) avcapturedevice *device = [Avcapturedevice defaultdevicewithmediatype:avmediatypevideo];
 Avcapturedeviceinput *input = [Avcapturedeviceinput deviceinputwithdevice:device error:nil];
 [Session Addinput:input]; 3, add Output data (Sample Object--> class object--> object--> root class object) avcapturemetadataoutput *output = [[Avcapturemetadataoutput alloc]
 INIT];
 [Output Setmetadataobjectsdelegate:self queue:dispatch_get_main_queue ()];
 [Session Addoutput:output]; 3.1. Set the type of input metadata (type is two-dimensional code data) [OUTput Setmetadataobjecttypes:@[avmetadataobjecttypeqrcode]];
 4, add scanning layer avcapturevideopreviewlayer *layer = [Avcapturevideopreviewlayer layerwithsession:session];
 Layer.frame = Self.view.bounds;
 [Self.view.layer Addsublayer:layer];
 Self.layer = layer;
5, start scanning [session startrunning]; /** * Implement output callback method/-(void) Captureoutput: (Avcaptureoutput *) captureoutput didoutputmetadataobjects: (Nsarray *) met Adataobjects fromconnection: (avcaptureconnection *) connection {//array metadataobjects holds the result data if (metadataobjects.count
 > 0) {//Get final read result avmetadatamachinereadablecodeobject *object = [Metadataobjects lastobject];
 NSLog (@ "%@", Object.stringvalue);
 [Self.session stoprunning];
 [Self.layer Removefromsuperlayer];
 else {NSLog (@ "No scan to data"); }
}

Summed up one sentence: This two-dimensional code is not difficult to use

This is the end of this article, iOS notes 061 two-dimensional code generation and scanning hope that in the future work and learning can help everyone. The following article gives you some information on how to use a two-dimensional code on an Apple iOS device, and you need to know the friend click here.