Coder Perfect

To enable the common picture formats, set the filter to an OpenFileDialog.


I’ve got this code; how can I make it accept all common picture formats? What are the differences between PNG, JPEG, JPG, and GIF?

Here’s what I’ve come up with thus far:

public void EncryptFile()
    OpenFileDialog dialog = new OpenFileDialog();
    dialog.Filter = "txt files (*.txt)|*.txt|All files (*.*)|*.*";
    dialog.InitialDirectory = @"C:\";
    dialog.Title = "Please select an image file to encrypt.";

    if (dialog.ShowDialog() == DialogResult.OK)
        //Encrypt the selected file. I'll do this later. :)

The filter is set to only accept.txt files, as you can see. I could use PNG, but what about the other file formats?

Asked by Sergio Tapia

Solution #1

The filter syntax you’ll need is as follows, according to the documentation:

Office Files|*.doc;*.xls;*.ppt

i.e. use a semicolon to separate the multiple extensions — for example, Image Files|*.jpg;*.jpeg;*.png;….

Answered by itowlson

Solution #2

Here’s an example of an ImageCodecInfo proposal (written in Visual Basic):

   Imports System.Drawing.Imaging

        Dim ofd as new OpenFileDialog()
        ofd.Filter = ""
        Dim codecs As ImageCodecInfo() = ImageCodecInfo.GetImageEncoders()
        Dim sep As String = String.Empty
        For Each c As ImageCodecInfo In codecs
            Dim codecName As String = c.CodecName.Substring(8).Replace("Codec", "Files").Trim()
            ofd.Filter = String.Format("{0}{1}{2} ({3})|{3}", ofd.Filter, sep, codecName, c.FilenameExtension)
            sep = "|"
        ofd.Filter = String.Format("{0}{1}{2} ({3})|{3}", ofd.Filter, sep, "All Files", "*.*")

And it appears to be as follows:

Answered by Tom Faust

Solution #3

Here is the complete C# solution:

private void btnSelectImage_Click(object sender, RoutedEventArgs e)
    // Configure open file dialog box 
    Microsoft.Win32.OpenFileDialog dlg = new Microsoft.Win32.OpenFileDialog();
    dlg.Filter = "";

    ImageCodecInfo[] codecs = ImageCodecInfo.GetImageEncoders();
    string sep = string.Empty;

    foreach (var c in codecs)
       string codecName = c.CodecName.Substring(8).Replace("Codec", "Files").Trim();
       dlg.Filter = String.Format("{0}{1}{2} ({3})|{3}", dlg.Filter, sep, codecName, c.FilenameExtension);
       sep = "|";

    dlg.Filter = String.Format("{0}{1}{2} ({3})|{3}", dlg.Filter, sep, "All Files", "*.*"); 

    dlg.DefaultExt = ".png"; // Default file extension 

    // Show open file dialog box 
    Nullable<bool> result = dlg.ShowDialog();

    // Process open file dialog box results 
    if (result == true)
       // Open document 
       string fileName  = dlg.FileName;
       // Do something with fileName  

Answered by NoWar

Solution #4

Use this code sample to filter image files.

//Create a new instance of openFileDialog
OpenFileDialog res = new OpenFileDialog();

res.Filter = "Image Files|*.jpg;*.jpeg;*.png;*.gif;*.tif;...";

//When the user select the file
if (res.ShowDialog() == DialogResult.OK)
   //Get the file's path
   var filePath = res.FileName;
   //Do something

Answered by HermF

Solution #5

Tom Faust’s response is my favorite. Here’s a C# version of his solution, with some simplifications.

var codecs = ImageCodecInfo.GetImageEncoders(); 
var codecFilter = "Image Files|"; 
foreach (var codec in codecs) 
    codecFilter += codec.FilenameExtension + ";"; 
dialog.Filter = codecFilter;

Answered by NielW

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