Question

Hi i’m doing a simple image viewer in C#. It has 3 button first button contain “Open” and the last two button is “Back and Next” and the picturebox. I’m done with the open button using OpenFileDialog Here’s my code in OpenFiledialog:

 private void openButton_Click(object sender, EventArgs e)
    {
        OpenFileDialog openFileDialog = new OpenFileDialog();
        openFileDialog.Filter = "JPEG|*.jpg|Bitmaps|*.bmp";

        if(openFileDialog.ShowDialog()== DialogResult.OK)
        {
            pictureBox1.Image = Bitmap.FromFile(openFileDialog.FileName);
        }
    }

Now this is the problem i don’t have idea what code can i use the in “next and back” button. i know it’s looping. Need you’re help guys thank you..

Answer 1

Here’s working user control code. You’ll need to create new Window Forms Application, create user control called MyPictureViewer. Add pictureBox, and 3 buttons to this control.
Paste below code to this usercontrol codebehind, hook click events, and add this control to main form. Hope this helps

public partial class MyPictureViewer : UserControl
{
    protected string[] pFileNames;
    protected int pCurrentImage = -1;

    public MyPictureViewer()
    {
        InitializeComponent();
    }

    void btnPrevImage_Click(object sender, EventArgs e)
    {
        if (pFileNames.Length > 0)
        {
            pCurrentImage = pCurrentImage == 0 ? pFileNames.Length - 1 : --pCurrentImage;
            ShowCurrentImage();
        }
    }

    void btnNextImage_Click(object sender, EventArgs e)
    {
        if (pFileNames.Length > 0)
        {
            pCurrentImage = pCurrentImage == pFileNames.Length - 1 ? 0 : ++pCurrentImage;
            ShowCurrentImage();
        }
    }

    private void openButton_Click(object sender, EventArgs e)
    {
        OpenFileDialog openFileDialog = new OpenFileDialog();
        openFileDialog.Multiselect = true;
        openFileDialog.Filter = "JPEG|*.jpg|Bitmaps|*.bmp";

        if (openFileDialog.ShowDialog() == DialogResult.OK)
        {
            pFileNames = openFileDialog.FileNames;
            pCurrentImage = 0;
            ShowCurrentImage();
        }
    }

    protected void ShowCurrentImage()
    {
        if (pCurrentImage >= 0 && pCurrentImage <= pFileNames.Length - 1)
        {
            pictureBox1.Image = Bitmap.FromFile(pFileNames[pCurrentImage]);
        }
    }
}