Convert NSView to NSImage: [self.layer renderInContext:ctx]; not working on macOS High Sierra (10.13)

Question

vsmedia OP

Created Sep ’17

Replies 1

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Views 4.7k

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I used this code from this site in old macOS versions to take an image of an NSView:

- (NSImage *)imageRepresentation
{
  BOOL wasHidden = self.isHidden;
  BOOL wantedLayer = self.wantsLayer;

  self.hidden = NO;
  self.wantsLayer = YES;

  NSImage *image = [[NSImage alloc] initWithSize:self.bounds.size];
  [image lockFocus];
  CGContextRef ctx = [NSGraphicsContext currentContext].CGContext;
  [self.layer renderInContext:ctx];
  [image unlockFocus];

  self.wantsLayer = wantedLayer;
  self.hidden = wasHidden;

  return image;

  }

It has always worked without problems so far.

Now, with macOS High Sierra (10.13) the returned image is empty. How can I solve the problem?

Answered by vsmedia in 264461022

The solution:

- (NSImage *)imageRepresentation
{
  NSSize mySize = self.bounds.size;
  NSSize imgSize = NSMakeSize( mySize.width, mySize.height );

  NSBitmapImageRep *bir = [self bitmapImageRepForCachingDisplayInRect:[self bounds]];
  [bir setSize:imgSize];
  [self cacheDisplayInRect:[self bounds] toBitmapImageRep:bir];

  NSImage* image = [[NSImage alloc]initWithSize:imgSize] ;
  [image addRepresentation:bir];
  return image;
}

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Answer 1

vsmedia OP

Sep ’17

Accepted Answer

The solution:

- (NSImage *)imageRepresentation
{
  NSSize mySize = self.bounds.size;
  NSSize imgSize = NSMakeSize( mySize.width, mySize.height );

  NSBitmapImageRep *bir = [self bitmapImageRepForCachingDisplayInRect:[self bounds]];
  [bir setSize:imgSize];
  [self cacheDisplayInRect:[self bounds] toBitmapImageRep:bir];

  NSImage* image = [[NSImage alloc]initWithSize:imgSize] ;
  [image addRepresentation:bir];
  return image;
}

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