CGImage.ScreenImage Method

Definition

Namespace:

CoreGraphics

Assembly:

Xamarin.iOS.dll

Overloads

ScreenImage

Takes a screenshot.

ScreenImage

Takes a screenshot.

public static CoreGraphics.CGImage ScreenImage { get; }

member this.ScreenImage : CoreGraphics.CGImage

Returns

CGImage

A CGImage

Remarks

This property will return a new image with the current contents of the screen.

Since this is a new image from the screen, it will generate a new image each time it is invoked. On an iPhone4S this will consume about 2 megs of memory (960*640*3) that you might want to Dispose as soon as you are done using it, to return the memory to the operating system.

In particular if you are taking many screenshots in a tight loop, you will want to ensure that the memory is released as soon as you use it. The following example shows one way of explicitly disposing the memory. It uses an NSAutoReleasePool to ensure that the image is disposed before we return control to the main loop processing.

//
// Notice that this does not return control to the main loop,
// so the images, even if disposed by the `using' statement
// would not be released, because they are added to the main
// loop NSAutoReleasePool.   This sample uses an explicit
// NSAutoReleasePool that is disposed immediately after 
// it is used.
//
while (true){
    using (var pool = new NSAutoreleasePool ()) {
        using (var img = CGImage.ScreenImage) {       

        	// Use the contents of the image.
        }
    }
}