ios - Add blur in UICollectionViewCell -

i'm trying snapshot of uicollectionviewcell, blur , add subview uicollectionviewcell.

some weird problems happening.

mycollectionviewcontroller  - (uicollectionviewcell *)collectionview:(uicollectionview *)collectionview cellforitematindexpath:(nsindexpath *)indexpath {     uicollectionviewcell<mycollectionviewcellprotocol> *cell = [collectionview dequeuereusablecellwithreuseidentifier:@"mycollectionviewcell" forindexpath:indexpath];     cell.modelvariable = self.modelsarray[indexpath.item];     return cell; }    @interface mycollectionviewcell : uicollectionviewcell <mycollectionviewcellprotocol>  @property (strong, nonatomic) promo *modelvariable;  @end   #import "uiimage+imageeffects.h" // wwdc 2013 #import "uiview+snapshot.h" // category create snapshot uiview @implementation promorowcollectionviewcell  - (void)setmodelvariable:(modelvariableclass *)modelvariable {     _modelvariable = modelvariable;      // settings other stuff importante cell view     self.mainimageview.image = modelvariable.mainimage;     self.titlelabel.text = modelvariable.title;     self.shortdescriptionlabel.text = modelvariable.detaileddescription;      // removing snapshot before taking other snapshot     // or in case cell reused , modelvariable not in blurstate     [self.blurimageview removefromsuperview];     self.blurimageview = nil;     [self.myview removefromsuperview];     self.myview = nil;      if (modelvariable.state == blurstate) {         // attempt 1 //        uigraphicsbeginimagecontext(self.bounds.size); //        [self drawviewhierarchyinrect:self.bounds afterscreenupdates:yes]; //        uiimage *image = uigraphicsgetimagefromcurrentimagecontext(); //        uigraphicsendimagecontext();          // attempt 2 //        uigraphicsbeginimagecontextwithoptions(self.bounds.size, self.opaque, 0.0); //        [self.layer renderincontext:uigraphicsgetcurrentcontext()]; //        uiimage *imgage = uigraphicsgetimagefromcurrentimagecontext(); //        uigraphicsendimagecontext();          // test showed weird behavior //        uiview *snapshotview = [self snapshotviewafterscreenupdates:yes]; //        self.myview = snapshotview; //        snapshotview.backgroundcolor = [uicolor colorwithred:1 green:0 blue:0 alpha:0.2]; //        cgrect frame = snapshotview.frame; //        frame.origin = cgpointmake(20, 20); //        snapshotview.frame = frame; //        [self addsubview:snapshotview];          // attempt 3 // red background , shifting frame can see red rectangle , not snapshot         uiview *snapshotview = [self snapshotviewafterscreenupdates:yes];         snapshotview.backgroundcolor = [uicolor colorwithred:1 green:0 blue:0 alpha:0.2]; // see things better  //        self.blockedpromoimageview = [[uiimageview alloc] initwithimage:image]; // attempts 1 , 2          self.blurimageview = [[uiimageview alloc] initwithimage:snapshotview.snapshotimage.applylighteffect];  //        self.blurimageview.frame = self.bounds;         self.blockedpromoimageview.frame = cgrectmake(20, 20, self.bounds.size.width, self.bounds.size.height); // see things better  //        self.blockedpromoimageview.backgroundcolor = [uicolor colorwithred:1 green:0 blue:0 alpha:0.2]; // attempts 1 , 2          [self addsubview:self.blurimageview];     } }  @end   uiview+snapshot  - (uiimage *)snapshotimage {     uigraphicsbeginimagecontextwithoptions(self.bounds.size, no, 0.0);     [self.layer renderincontext:uigraphicsgetcurrentcontext()];     uiimage *resultingimage = uigraphicsgetimagefromcurrentimagecontext();     uigraphicsendimagecontext();     return resultingimage; } 

attempt 1:

attempt 2:

test weird behavior:

attempt 3:

so can see, attempts 1, 2 , 3 seems didn't take snapshot. i'd expect red rectangle have snapshot of view in back.

as weird behavior test, i'd expect can seen in image, except red rectangle @ front.

does knows whats going on? or how solve it?

thank you.

edit:

i created simple project minimum amount of code reproduce problem. https://www.dropbox.com/sh/j1mhxj367kzn81y/aadw8ds9nvlmyjudbn08mojxa?dl=0

you don't need use afterscreenupdates flag if want image , text change come through in screenshot.

you can edit image , text, remove views , save cell image in standard way:

-(uiimage*) takesnapshot {      uigraphicsbeginimagecontext(self.frame.size);     [self.layer renderincontext: uigraphicsgetcurrentcontext()];     uiimage *image = uigraphicsgetimagefromcurrentimagecontext();     uigraphicsendimagecontext();      return image; } 

then add blur , add view.

if (modelvariable.state == blurstate) {     uiimage *snapshot = [self takesnapshot];     uiimage *blurredimage = [snapshot applylighteffect];      self.blurredimageview = [[uiimageview alloc] initwithimage:blurredimage];     [self.view addsubview:self.blurredimageview]; }