Saving Clipboard PrintScreen to Image File in C#

Question

Hello Everyone,

I'm a new poster here and apologize in advance if I have posted this in the wrong subforum.

I am trying to use Visual Studio C# to printscreen, then save the screen capture to a file.

Currently, I am having problems reading from the clipboard. I have tried using both of the following lines to save a screen capture to the clipboard:

SendKeys.SendWait("+{PRTSC}");
SendKeys.SendWait("{PRTSC}");

However, when I try to save the image using the following lines, I get a Null Reference Exception.

image = (Image)Clipboard.GetDataObject().GetData(DataFormats.Bitmap);
image.Save("image.jpeg", System.Drawing.Imaging.ImageFormat.Jpeg);

I have tested if the clipboard actually contains an image, and the following lines indicate that it thinks the clipboard is empty. i.e. the program writes "Clipboard empty."

if (Clipboard.GetDataObject() == null)
{
Console.WriteLine("Clipboard empty.");
}

However, I know that it is not empty since I can paste the screen capture to paint after running the code.

I have looked at many tutorials on how to save screenshots to image files and don't know what I am doing wrong here. Any help would be much appreciated.

Thanks!

孙卓识 孙卓识 · Answer

I've suffered from the same issue, access clipboard in C# requires a STA thread. You may try code like this: Thread thread = new Thread(() => { # Access Clipboard here }); thread.SetApartmentState(ApartmentState.STA); //Set the thread to STA thread.Start(); thread.Join(); You can find more detail info here: https://softwareengineering.stackexchange.com/questions/304742/why-does-the-windows-clipboard-require-an-sta-thread

Hemant Srivastava · Answer

try this one: if (Clipboard.ContainsImage() == true) { Image image = (Image)Clipboard.GetDataObject().GetData(DataFormats.Bitmap); image.Save("image.jpeg", System.Drawing.Imaging.ImageFormat.Jpeg); } else { Console.WriteLine("Clipboard empty."); }