ios 图文混排（coretext.framework）
本文主要介绍了ios图文混排的资料，这里整理了在网上查找的内容，帮助理解，掌握这部分知识，以下就是整理的内容：
利用coretext进行图文混排。
实现代码：
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void rundelegatedealloccallback( void* refcon ){
}
cgfloat rundelegategetascentcallback( void *refcon ){
nsstring *imagename = (nsstring *)refcon;
return 80;//[uiimage imagenamed:imagename].size.height;
}
cgfloat rundelegategetdescentcallback(void *refcon){
return 0;
}
cgfloat rundelegategetwidthcallback(void *refcon){
nsstring *imagename = (nsstring *)refcon;
return 100;//[uiimage imagenamed:imagename].size.width;
}
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先设置一个ctrun的委托，主要是用于指定对象的上行高，宽，或上下文释放时使用。
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-(void)drawcharandpicture
{
cgcontextref context = uigraphicsgetcurrentcontext();
cgcontextsettextmatrix(context, cgaffinetransformidentity);//设置字形变换矩阵为cgaffinetransformidentity，也就是说每一个字形都不做图形变换
cgaffinetransform flipvertical = cgaffinetransformmake(1,0,0,-1,0,self.bounds.size.height);
cgcontextconcatctm(context, flipvertical);//将当前context的坐标系进行flip
nslog(@"bh=%f",self.bounds.size.height);
nsmutableattributedstring *attributedstring = [[[nsmutableattributedstring alloc] initwithstring:@"请在这里插入一张图片位置"] autorelease];
//为图片设置ctrundelegate,delegate决定留给图片的空间大小
nsstring *imgname = @"img.png";
ctrundelegatecallbacks imagecallbacks;
imagecallbacks.version = kctrundelegateversion1;
imagecallbacks.dealloc = rundelegatedealloccallback;
imagecallbacks.getascent = rundelegategetascentcallback;
imagecallbacks.getdescent = rundelegategetdescentcallback;
imagecallbacks.getwidth = rundelegategetwidthcallback;
ctrundelegateref rundelegate = ctrundelegatecreate(&imagecallbacks, imgname);
nsmutableattributedstring *imageattributedstring = [[nsmutableattributedstring alloc] initwithstring:@" "];//空格用于给图片留位置
[imageattributedstring addattribute:(nsstring *)kctrundelegateattributename value:(id)rundelegate range:nsmakerange(0, 1)];
cfrelease(rundelegate);
[imageattributedstring addattribute:@"imagename" value:imgname range:nsmakerange(0, 1)];
[attributedstring insertattributedstring:imageattributedstring atindex:4];
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//换行模式
ctparagraphstylesetting linebreakmode;
ctlinebreakmode linebreak = kctlinebreakbycharwrapping;
linebreakmode.spec = kctparagraphstylespecifierlinebreakmode;
linebreakmode.value = &linebreak;
linebreakmode.valuesize = sizeof(ctlinebreakmode);
ctparagraphstylesetting settings[] = {
linebreakmode
};
ctparagraphstyleref style = ctparagraphstylecreate(settings, 1);
// build attributes
nsmutabledictionary *attributes = [nsmutabledictionary dictionarywithobject:(id)style forkey:(id)kctparagraphstyleattributename ];
// set attributes to attributed string
[attributedstring addattributes:attributes range:nsmakerange(0, [attributedstring length])];
ctframesetterref ctframesetter = ctframesettercreatewithattributedstring((cfmutableattributedstringref)attributedstring);
cgmutablepathref path = cgpathcreatemutable();
cgrect bounds = cgrectmake(0.0, 0.0, self.bounds.size.width, self.bounds.size.height);
cgpathaddrect(path, null, bounds);
ctframeref ctframe = ctframesettercreateframe(ctframesetter,cfrangemake(0, 0), path, null);
ctframedraw(ctframe, context);
cfarrayref lines = ctframegetlines(ctframe);
cgpoint lineorigins[cfarraygetcount(lines)];
ctframegetlineorigins(ctframe, cfrangemake(0, 0), lineorigins);
nslog(@"line count = %ld",cfarraygetcount(lines));
for (int i = 0; i < cfarraygetcount(lines); i++) {
ctlineref line = cfarraygetvalueatindex(lines, i);
cgfloat lineascent;
cgfloat linedescent;
cgfloat lineleading;
ctlinegettypographicbounds(line, &lineascent, &linedescent, &lineleading);
nslog(@"ascent = %f,descent = %f,leading = %f",lineascent,linedescent,lineleading);
cfarrayref runs = ctlinegetglyphruns(line);
nslog(@"run count = %ld",cfarraygetcount(runs));
for (int j = 0; j < cfarraygetcount(runs); j++) {
cgfloat runascent;
cgfloat rundescent;
cgpoint lineorigin = lineorigins[i];
ctrunref run = cfarraygetvalueatindex(runs, j);
nsdictionary* attributes = (nsdictionary*)ctrungetattributes(run);
cgrect runrect;
runrect.size.width = ctrungettypographicbounds(run, cfrangemake(0,0), &runascent, &rundescent, null);
nslog(@"width = %f",runrect.size.width);
runrect=cgrectmake(lineorigin.x + ctlinegetoffsetforstringindex(line, ctrungetstringrange(run).location, null), lineorigin.y - rundescent, runrect.size.width, runascent + rundescent);
nsstring *imagename = [attributes objectforkey:@"imagename"];
//图片渲染逻辑
if (imagename) {
uiimage *image = [uiimage imagenamed:imagename];
if (image) {
cgrect imagedrawrect;
imagedrawrect.size = image.size;
imagedrawrect.origin.x = runrect.origin.x + lineorigin.x;
imagedrawrect.origin.y = lineorigin.y;
cgcontextdrawimage(context, imagedrawrect, image.cgimage);
}
}
}
}
cfrelease(ctframe);
cfrelease(path);
cfrelease(ctframesetter);
}
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效果：
从上面看大家可能没有发现什么问题，当把图片放在字的最左边会是什么样子的？
因此为了避免这种情况发生，我在代码中添加了换行模式。添加换行后的效果：
感谢阅读，希望能帮助到大家，谢谢大家对本站的支持！
原文链接：http://blog.csdn.net/fengsh998/article/details/8714497