Turn a picture into a circle

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Code:

-(void) viewdidload {[Super viewdidload];        Additional setup after loading the view, typically from a nib.    Uiimageview *imageview=[[uiimageview Alloc] Initwithframe:cgrectmake (20, 50, 100, 100)];    Imageview.image=[self changeimagetocilce:[uiimage imagenamed:@ "1.png"];        [Self.view Addsubview:imageview];    }//processing the picture into a circle-(ID) Changeimagetocilce: (uiimage*) image{UIImage *finalimage = nil;    Uigraphicsbeginimagecontext (image.size);        {Cgcontextref CTX = Uigraphicsgetcurrentcontext (); Cgaffinetransform trnsfrm = Cgaffinetransformconcat (cgaffinetransformidentity, Cgaffinetransformmakescale (1.0, 1.0        ));        Trnsfrm = Cgaffinetransformconcat (trnsfrm, cgaffinetransformmaketranslation (0.0, image.size.height));        CGCONTEXTCONCATCTM (CTX, trnsfrm);        Cgcontextbeginpath (CTX);        Cgcontextaddellipseinrect (CTX, CGRectMake (0.0, 0.0, image.size.width, image.size.height));        Cgcontextclip (CTX); Cgcontextdrawimage (CTX, CGRectMake(0.0, 0.0, image.size.width, image.size.height), image.        Cgimage);        Finalimage = Uigraphicsgetimagefromcurrentimagecontext ();    Uigraphicsendimagecontext (); } return finalimage;}

Turn a picture into a circle