CODEWITHSUNDEEP
c#wpfinteropbitmapimage
Torsten Crull
Torsten Crull

Reputation: 133

WPF Image: .Source = Clipboard.GetImage() is not displayed

This simple program does not work, the image does not appear in the Window.

namespace ClipBoardTest
{
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
        }
        private void CopyButton_Click(object sender, RoutedEventArgs e)
        {
            if (Clipboard.ContainsImage())
            {
                ImageUIElement.Source = Clipboard.GetImage();
                Console.WriteLine("Clipboard copied to UIElement");
            }
            else
            {
                Console.WriteLine("No image in Clipboard");
            }
        }
    }
 }

Output is "Clipboard copied to UIElement", but the image does not appear in the Window.

XAML:

 <Window x:Class="ClipBoardTest.MainWindow"
         xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
         xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
         Title="MainWindow" Height="350" Width="525">
     <Grid>
         <Button x:Name="CopyButton" Content="Copy" HorizontalAlignment="Left" Margin="10,10,0,0" VerticalAlignment="Top" Width="75" Click="CopyButton_Click"/>
         <Image x:Name="ImageUIElement" Margin="90,10,10,10"/>
     </Grid>
 </Window>

Is there anybody, who understands, what is wrong?

Upvotes: 4

Views: 8430

Answers (3)

Andrea Antonangeli
Andrea Antonangeli

Reputation: 1262

Visual Studio 2019, WPF C# project targeting .NET Core 3.1, the following works (or, at least, it does for me):

myImage.Source = GetImageFromClipBoard();

where:

public static ImageSource GetImageFromClipBoard ()
        {
        if (Clipboard.ContainsImage())
            {
            return Clipboard.GetImage();
            }
        else
            return null;
        }

Upvotes: 4

Torsten Crull
Torsten Crull

Reputation: 133

Now it works fine.

if (Clipboard.ContainsImage())
{
    // ImageUIElement.Source = Clipboard.GetImage(); // does not work
    System.Windows.Forms.IDataObject clipboardData = System.Windows.Forms.Clipboard.GetDataObject();
    if (clipboardData != null)
    {
        if (clipboardData.GetDataPresent(System.Windows.Forms.DataFormats.Bitmap))
        {
            System.Drawing.Bitmap bitmap = (System.Drawing.Bitmap)clipboardData.GetData(System.Windows.Forms.DataFormats.Bitmap);
            ImageUIElement.Source =  System.Windows.Interop.Imaging.CreateBitmapSourceFromHBitmap(bitmap.GetHbitmap(), IntPtr.Zero, Int32Rect.Empty,BitmapSizeOptions.FromEmptyOptions());
            Console.WriteLine("Clipboard copied to UIElement");
        }
    }
}

Upvotes: 1

Rohit Vats
Rohit Vats

Reputation: 81233

Use Clipboard.GetDataObject to get bitmap and convert it into bitmapSource. Also, be aware that Bitmap.GetHbitmap() leaks memory unless you call DeleteObject on it.

So, correct solution would be to dispose the IntPtr after use. Declare the method at class level and use it from your code:

// at class level
[System.Runtime.InteropServices.DllImport("gdi32.dll")]
public static extern bool DeleteObject(IntPtr hObject);

if (Clipboard.ContainsImage())
{
    IDataObject clipboardData = Clipboard.GetDataObject();
    if (clipboardData != null)
    {
        if (clipboardData.GetDataPresent(System.Windows.Forms.DataFormats.Bitmap))
        {
            System.Drawing.Bitmap bitmap = (System.Drawing.Bitmap)clipboardData.GetData(System.Windows.Forms.DataFormats.Bitmap);
            IntPtr hBitmap = bitmap.GetHbitmap();
            try
            {
                ImageUIElement.Source = System.Windows.Interop.Imaging.CreateBitmapSourceFromHBitmap(hBitmap, IntPtr.Zero, Int32Rect.Empty, BitmapSizeOptions.FromEmptyOptions());
                Console.WriteLine("Clipboard copied to UIElement");
            }
            finally 
            {
                DeleteObject(hBitmap)
            }
        }
    }
}

Source - MSDN and Memory leak in Bitmap.

Upvotes: 7

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