C# System.Drawing.Bitmap <-- how to check if image is valid before adding it to picturebox!

Question

How do I do that in C#? :) Thx!

Answer 1

Perhaps you should check this 'RawFormat' property of the 'System.Drawing.Bitmap' class as shown here on MSDN. If the image is empty, that will throw an exception and you can trap it in that case.

Hope this helps, Best regards, Tom.

Answer 2

1. Define "valid"

2. write a valdation function

3. call it on the image

4. if it passes, load the image, otherwise don't

Answer 3

It is pretty simple. If you can load the image before you assign it to the picture box then you've sufficiently proven that the image is valid and that the user has something to look at. The GDI+ image decoders very carefully check the file contents. Thus:

    private void button1_Click(object sender, EventArgs e) {
        if (openFileDialog1.ShowDialog(this) != DialogResult.OK) return;
        try {
            Bitmap bmp = new Bitmap(openFileDialog1.FileName);
            if (pictureBox1.Image != null) pictureBox1.Image.Dispose();
            pictureBox1.Image = bmp;
        }
        catch (Exception ex) {
            MessageBox.Show(ex.Message, "Could not load image");
        }
    }