Saving Image in WPF C# with an error System.UnauthorizedAccessException occurred in mscorlib.dll

Question

I am creating a WPF application of a diagram designer and it only saved as .xml, I would also like to export it as png.

I have this code.

 public static void ExportToPng(UIElement target, string ImagePath)
    {
        // Prepare target-layout
        Size size = target.RenderSize;
        target.Measure(size);
        target.Arrange(new Rect(size));

        // Render diagram to bitmap
        RenderTargetBitmap renderBitmap =
            new RenderTargetBitmap(
                (int)size.Width,
                (int)size.Height,
                96, 96,
                PixelFormats.Pbgra32);
        renderBitmap.Render(target);

        // Convert bitmap to png
        PngBitmapEncoder encoder = new PngBitmapEncoder();
        encoder.Frames.Add(BitmapFrame.Create(renderBitmap));

I've searched for the code and it says that:

The final step is to save the image to the disk (or wherever you like). The PngBitmapEncoder provides the possibility to save to a stream. In this tutorial we’ll pass a StreamWriter to it, to save the image to the path we passed into the method. Add the following code to the method ExportToPng:

        using (FileStream fileStream = new FileStream(ImagePath, FileMode.Create))
        {
            encoder.Save(fileStream);
        }
    }
}

I want to ask if this fileStream is really required or not. I'm sorry im just newbie in c# and also to WPF.

I included it also because it says so, the last part is like this:

With this you have the diagram-export method completed. Now how and where can you call it? Let me answer the first question first. You can call it like this:

SelectionService.ClearSelection(); // Unselect DesignerItems
DiagramDesignerExporter.ExportToPng(<DesignerCanvas-Object>, "<YourFullFilePath>");

It also says that:

Where you want to call the ExportToPng-method depends a lot on what kind of application you build. If you just enhance the original WPF Diagram Designer, then you most likely add a new button to the Ribbon-Toolbar and add a new method into the file DesignerCanvas.Commands.cs. If you do so, you can call the method simply like this:

DiagramDesignerExporter.ExportToPng(this, <YourFullFilePath>);

I also want to ask if what i want to place in the . And i assumed that it was a place on my laptop. so I called it like this:

 DiagramDesignerExporter.ExportToPng(this, "C:/Users/Sony/Pictures");

I run it and I had an error like this:

An unhandled exception of type 'System.UnauthorizedAccessException' occurred in mscorlib.dll

Additional information: Access to the path 'C:\Users\Sony\Pictures' is denied.

I tried to call it like this:

 DiagramDesignerExporter.ExportToPng(this, "C:/Users/Sony/Pictures");

but its not functioning. I hope someone could help me to this. Thanks.

Answer 1

You have to specify a full path including a file name, not only a folder path:

DiagramDesignerExporter.ExportToPng(this, @"C:\Users\Sony\Pictures\Image1.png");