Nt_ios Notes-coretext Add text background color (search highlighting)

Reprint please indicate source: http://blog.csdn.net/nt_tian/article/details/42458647

In Coretext full-text search, the results of the search need to be highlighted, this is a very common practice.

The search results list can be directly displayed by Uilabel

[Attributedstring addattribute:nsbackgroundcolorattributename value:[uicolor Orangecolor] Range:range];_ conlabel.attributedtext=attributedstring;

But when I started coretext text highlighting, I found a problem, Coretextnsmutableattributedstring in theThe Nsbackgroundcolorattributename property is not supported.
online Check, coretext text background color need to manually draw up.

Well, then you can only draw it yourself, on the code:

-(void) DrawRect: (cgrect) rect{cgcontextref context = Uigraphicsgetcurrentcontext ();    Cgcontextsettextmatrix (context, cgaffinetransformidentity);    CGCONTEXTTRANSLATECTM (context, 0, self.bounds.size.height); CGCONTEXTSCALECTM (Context, 1.0,-1.0);    Nsarray *lines = (Nsarray *) Ctframegetlines ((ctframeref) nctframe);        if (lines.count) {Cgpoint *lineorigins = malloc (lines.count * sizeof (cgpoint));        Ctframegetlineorigins ((ctframeref) nctframe, Cfrangemake (0, Lines.count), lineorigins);        int i = 0;            For (ID aLine in lines) {Nsarray *glyphruns = (Nsarray *) ctlinegetglyphruns ((ctlineref) aLine);            CGFloat width =lineorigins[i].x-lineorigins[0].x;            CGFloat height =lineorigins[i].y;                For (ID run in glyphruns) {Cfdictionaryref dicref=ctrungetattributes ((ctrunref) run);                Nsdictionary *dic= (__bridge nsdictionary *) dicref; if ([DiC objectforkey:@ "Nsbackgroundcolor"]!=nil&&_issearch==yes) {uicolor *bgcolor=[dic objectforkey:@" Nsbackgroundcolo                    R "];                    Cgpoint *ary= (Cgpoint *) ctrungetpositionsptr ((ctrunref) run);                    float lineheight; if (lines.count>=2) {Lineheight=lineorigins[lines.count-2].y-lineorigins[lin                    ES.COUNT-1].Y;                    } else {lineheight=28;                    } float Runwidth=ctrungettypographicbounds ((ctrunref) run, cfrangemake (0, 0), NULL, NULL, NULL);                    CGRect rectangle = CGRectMake (ary[0].x, Height-8, Runwidth, lineheight);                    Cgcontextsetfillcolorwithcolor (Context,bgcolor.cgcolor);                    Cgcontextfillrect (context, rectangle); Draw Rectangle//Cgcontextsetstrokecolorwithcolor (context, [BGColor cgcolor]);//Border color//cgcontextaddrect (context, rectangle);//Cgcontextstrokepath (context);//Draw            }                ......            }        i++;    } free (lineorigins); }}

There's also a problem here. There is no good way to find it at the moment: there is no good way to get a high line.

If anyone knows can tell me, I can also learn to improve.

Nt_ios Notes-coretext Add text background color (search highlighting)