Objective-C Requires Chilkat v11.7.0+

Generate a QR Code PNG in Memory

See more QR Code Examples

Demonstrates getting a QR code image without writing a file. With no output options the result is a PNG returned as base64 in outputs[0].base64 of the response. The example decodes it into a BinData, which holds the bytes of the PNG to send in an HTTP response, store in a database, attach to an email, or save. Objective-C

#import <CkoJsonObject.h>
#import <CkoFormats.h>
#import <CkoBinData.h>

BOOL success = NO;

//  This example requires the Chilkat API to have been previously unlocked.
//  See Global Unlock Sample for sample code.

CkoJsonObject *json = [[CkoJsonObject alloc] init];
[json UpdateString: @"payload.text" value: @"https://www.chilkatsoft.com/"];
[json UpdateInt: @"render.moduleSize" value: [NSNumber numberWithInt: 6]];

CkoFormats *fmt = [[CkoFormats alloc] init];
CkoJsonObject *jsonOut = [[CkoJsonObject alloc] init];
success = [fmt QrCode: @"generate" jsonIn: json jsonOut: jsonOut];
if (success == NO) {
    NSLog(@"%@",fmt.LastErrorText);
    return;
}

NSLog(@"%@%@",@"format: ",[jsonOut StringOf: @"outputs[0].format"]);
NSLog(@"%@%@",@"MIME type: ",[jsonOut StringOf: @"outputs[0].mimeType"]);
NSLog(@"%@%d%@%d%@",@"image: ",[[jsonOut IntOf: @"outputs[0].width"] intValue],@" x ",[[jsonOut IntOf: @"outputs[0].height"] intValue],@" pixels");

//  outputs[0].base64 is the PNG file, base64 encoded.
CkoBinData *bdPng = [[CkoBinData alloc] init];
success = [bdPng AppendEncoded: [jsonOut StringOf: @"outputs[0].base64"] encoding: @"base64"];
if (success == NO) {
    NSLog(@"%@",bdPng.LastErrorText);
    return;
}

NSLog(@"%@%d",@"PNG bytes: ",[bdPng.NumBytes intValue]);

//  The BinData holds the image.  Here it is simply saved.
success = [bdPng WriteFile: @"qa_output/qr_in_memory.png"];
if (success == NO) {
    NSLog(@"%@",bdPng.LastErrorText);
    return;
}

//  The PNG held in bdPng:

//  

//  Sample output:

//  format: png
//  MIME type: image/png
//  image: 222 x 222 pixels
//  PNG bytes: 877