iPhone iOS how to draw text on a CALayer using drawLayer:inContext:? -

i have simple scrolling graph uses method draw itself. i'm looking way add text label graph, cannot find how this.

i tried:

[@"test" drawinrect: cgrectmake(0, 0, 10, 10) withfont:[uifont systemfontofsize:8]]; 

and error messages saying invalid context 0x0. how modify code below point text drawing code correct context?

-(void)drawlayer:(calayer*)l incontext:(cgcontextref)context {     // fill in background     cgcontextsetfillcolorwithcolor(context, graphbackgroundcolor());     cgcontextfillrect(context, layer.bounds);      // draw grid lines //  drawgridlines(context, 0.0, 32.0);      // draw graph     cgpoint lines[64];     int i;     // x     for(i = 0; < 32; ++i)     {         lines[i*2].x = i;         lines[i*2].y = -(xhistory[i] * 480.0)-10;         lines[i*2+1].x = + 1;         lines[i*2+1].y = -(xhistory[i+1] * 480.0)-10;     }      cgcontextsetstrokecolorwithcolor(context, graphzcolor());     cgcontextstrokelinesegments(context, lines, 64); } 

for each thread, uikit maintains stack of graphics contexts. can context @ top of current thread's stack calling uigraphicsgetcurrentcontext.

when use drawinrect:withfont:, string draws context returned uigraphicsgetcurrentcontext, need make uigraphicsgetcurrentcontext return context argument of drawlayer:incontext: using uigraphicspushcontext. when done drawing, must call uigraphicspopcontext. thus:

-(void)drawlayer:(calayer*)l incontext:(cgcontextref)context {     uigraphicspushcontext(context); {         // fill in background         cgcontextsetfillcolorwithcolor(context, graphbackgroundcolor());         cgcontextfillrect(context, layer.bounds);         // etc.     } uigraphicspopcontext(); }