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ios 创建彩色二维码
因为系统创建的二维码默认都是黑色的，所以突然想改变一下二维码颜色，具体操作有点复杂，而且其中用到了好多c语言的语法，swift不好写，所以默认用了oc。只贴了.m文件的代码，.h文件就是几个类函数的声明。
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#import "uiimage+createqrcode.h"
@implementation uiimage (createqrcode)
+ (uiimage *)createqrcode:(nsstring *)string andsize:(cgsize)size andcolor:(uicolor *)color {
uiimage *qrcode = [self createnoninterpolateduiimageformciimage:[self createqrforstring:string] withsize:size];
const cgfloat *_components = cgcolorgetcomponents(color.cgcolor);
cgfloat red = _components[0] * 255.f;
cgfloat green = _components[1] * 255.f;
cgfloat blue = _components[2] * 255.f;
return [self imageblacktotransparent:qrcode withred:red andgreen:green andblue:blue];
}
+ (void)setimageviewshadow:(uiimageview *)view {
view.layer.shadowoffset = cgsizemake(0, 2);
view.layer.shadowradius = 2;
view.layer.shadowcolor = [uicolor blackcolor].cgcolor;
view.layer.shadowopacity = 0.5;
view.backgroundcolor = [uicolor clearcolor];
}
#pragma mark - 创建灰度图，只有灰度图才能改变颜色
+ (uiimage *)createnoninterpolateduiimageformciimage:(ciimage *)image withsize:(cgsize)size {
cgrect extent = cgrectintegral(image.extent);
cgfloat scale = min(size.width/cgrectgetwidth(extent), size.height/cgrectgetheight(extent));
size_t width = cgrectgetwidth(extent) * scale;
size_t height = cgrectgetheight(extent) * scale;
// ios不支持设备依赖颜色空间或通用颜色空间。ios应用程序必须使用设备颜色空间
// 设备颜色空间主要用于ios应用程序，因为其它颜色空间无法在ios上使用。大多数情况下，mac os x应用程序应使用通用颜色空间，而不使用设备颜色空间。
// cgcolorspacecreatedevicegray：创建设备依赖灰度颜色空间
// cgcolorspacecreatedevicergb：创建设备依赖rgb颜色空间
// cgcolorspacecreatedevicecmyk：创建设备依赖cmyk颜色空间
cgcolorspaceref cs = cgcolorspacecreatedevicegray();//这个是改变二维码颜色的主要属性，必须是灰度空间，作用是将uiimage转变成了灰度图
cgcontextref bitmapref = cgbitmapcontextcreate(null, width, height, 8, 0, cs, kcgimagealphanone);
cicontext * context = [cicontext contextwithoptions:null];
cgimageref bitmapimage = [context createcgimage:image fromrect:extent];
cgcontextsetinterpolationquality(bitmapref, kcginterpolationhigh);
cgcontextscalectm(bitmapref, scale, scale);
cgcontextdrawimage(bitmapref, extent, bitmapimage);
cgimageref scaledimage = cgbitmapcontextcreateimage(bitmapref);
cgcontextrelease(bitmapref);
cgimagerelease(bitmapimage);
return [uiimage imagewithcgimage:scaledimage];
}
#pragma mark - 创建二维码的主要代码
+ (ciimage *)createqrforstring:(nsstring *)qrstring {
nsdata *stringdata = [qrstring datausingencoding:nsutf8stringencoding];
cifilter *qrfilter = [cifilter filterwithname:@"ciqrcodegenerator"];
[qrfilter setvalue:stringdata forkey:@"inputmessage"];
[qrfilter setvalue:@"m" forkey:@"inputcorrectionlevel"];
return qrfilter.outputimage;
}
#pragma mark - 改变二维码的颜色
void providerreleasedata (voidvoid *info, const voidvoid *data, size_t size){
free((void*)data);
}
+ (uiimage*)imageblacktotransparent:(uiimage*)image withred:(cgfloat)red andgreen:(cgfloat)green andblue:(cgfloat)blue{
const int imagewidth = image.size.width;
const int imageheight = image.size.height;
size_t bytesperrow = imagewidth * 4;
uint32_t* rgbimagebuf = (uint32_t*)malloc(bytesperrow * imageheight);
cgcolorspaceref colorspace = cgcolorspacecreatedevicergb();
cgcontextref context = cgbitmapcontextcreate(rgbimagebuf, imagewidth, imageheight, 8, bytesperrow, colorspace,
kcgbitmapbyteorder32little | kcgimagealphanoneskiplast);
cgcontextdrawimage(context, cgrectmake(0, 0, imagewidth, imageheight), image.cgimage);
int pixelnum = imagewidth * imageheight;
uint32_t* pcurptr = rgbimagebuf;
for (int i = 0; i < pixelnum; i++, pcurptr++){
if ((*pcurptr & 0xffffff00) < 0x99999900){
uint8_t* ptr = (uint8_t*)pcurptr;
ptr[3] = red; //0~255
ptr[2] = green;
ptr[1] = blue;
}else{
uint8_t* ptr = (uint8_t*)pcurptr;
ptr[0] = 0;
}
}
cgdataproviderref dataprovider = cgdataprovidercreatewithdata(null, rgbimagebuf, bytesperrow * imageheight, providerreleasedata);
cgimageref imageref = cgimagecreate(imagewidth, imageheight, 8, 32, bytesperrow, colorspace,
kcgimagealphalast | kcgbitmapbyteorder32little, dataprovider,
null, true, kcgrenderingintentdefault);
cgdataproviderrelease(dataprovider);
uiimage* resultuiimage = [uiimage imagewithcgimage:imageref];
cgimagerelease(imageref);
cgcontextrelease(context);
cgcolorspacerelease(colorspace);
return resultuiimage;
}
@end
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