I have this code, how can I allow it to accept all typical image formats? PNG, JPEG, JPG, GIF?
Here's what I have so 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. :) } } Notice that the filter is set to .txt files. I could change to PNG, but what of the other types?
13 Answers
From the docs, the filter syntax that you need is as follows:
Office Files|*.doc;*.xls;*.ppt i.e. separate the multiple extensions with a semicolon -- thus, Image Files|*.jpg;*.jpeg;*.png;....
Here's an example of the ImageCodecInfo suggestion (in VB):
Imports System.Drawing.Imaging Imports System.Windows.Forms '... Using ofd as New OpenFileDialog() With { .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 = "|" Next c ofd.Filter = String.Format("{0}{1}{2} ({3})|{3}", ofd.Filter, sep, "All Files", "*.*") End Using And it looks like this:
Complete solution in C# is here:
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 } } To filter images files, use this code sample.
//Create a new instance of openFileDialog OpenFileDialog res = new OpenFileDialog(); //Filter 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 .... } I like Tom Faust's answer the best. Here's a C# version of his solution, but simplifying things a bit.
var codecs = ImageCodecInfo.GetImageEncoders(); var codecFilter = "Image Files|"; foreach (var codec in codecs) { codecFilter += codec.FilenameExtension + ";"; } dialog.Filter = codecFilter; For images, you could get the available codecs from GDI (System.Drawing) and build your list from that with a little work. This would be the most flexible way to go.
ImageCodecInfo[] codecs = ImageCodecInfo.GetImageEncoders(); Just a necrocomment for using string.Join and LINQ.
ImageCodecInfo[] codecs = ImageCodecInfo.GetImageEncoders(); dlgOpenMockImage.Filter = string.Format("{0}| All image files ({1})|{1}|All files|*", string.Join("|", codecs.Select(codec => string.Format("{0} ({1})|{1}", codec.CodecName, codec.FilenameExtension)).ToArray()), string.Join(";", codecs.Select(codec => codec.FilenameExtension).ToArray())); Write out the types that your application wants. (ref. FileDialog.Filter). Here are all the most common image formats.
private static string GetImageFilter() { return "All Files (*.*)|*.*" + "|All Pictures (*.emf;*.wmf;*.jpg;*.jpeg;*.jfif;*.jpe;*.png;*.bmp;*.dib;*.rle;*.gif;*.emz;*.wmz;*.tif;*.tiff;*.svg;*.ico)" + "|*.emf;*.wmf;*.jpg;*.jpeg;*.jfif;*.jpe;*.png;*.bmp;*.dib;*.rle;*.gif;*.emz;*.wmz;*.tif;*.tiff;*.svg;*.ico" + "|Windows Enhanced Metafile (*.emf)|*.emf" + "|Windows Metafile (*.wmf)|*.wmf" + "|JPEG File Interchange Format (*.jpg;*.jpeg;*.jfif;*.jpe)|*.jpg;*.jpeg;*.jfif;*.jpe" + "|Portable Network Graphics (*.png)|*.png" + "|Bitmap Image File (*.bmp;*.dib;*.rle)|*.bmp;*.dib;*.rle" + "|Compressed Windows Enhanced Metafile (*.emz)|*.emz" + "|Compressed Windows MetaFile (*.wmz)|*.wmz" + "|Tag Image File Format (*.tif;*.tiff)|*.tif;*.tiff" + "|Scalable Vector Graphics (*.svg)|*.svg" + "|Icon (*.ico)|*.ico"; } Example use
Set FilterIndex = 2 to preselect 'All pictures'. Don't set openFileDialog.InitialDirectory unless you have a good reason.
void OpenImageFile() { var openFileDialog = new OpenFileDialog { Filter = GetImageFilter(), FilterIndex = 2, RestoreDirectory = true }; DialogResult result = openFileDialog.ShowDialog(); // do something with your file // bool resultOk = (result == System.Windows.Forms.DialogResult.OK); // string filePath = openFileDialog.FileName; // ... } For those who don't want to remember the syntax everytime here is a simple encapsulation:
public class FileDialogFilter : List<string> { public string Explanation { get; } public FileDialogFilter(string explanation, params string[] extensions) { Explanation = explanation; AddRange(extensions); } public string GetFileDialogRepresentation() { if (!this.Any()) { throw new ArgumentException("No file extension is defined."); } StringBuilder builder = new StringBuilder(); builder.Append(Explanation); builder.Append(" ("); builder.Append(String.Join(", ", this)); builder.Append(")"); builder.Append("|"); builder.Append(String.Join(";", this)); return builder.ToString(); } } public class FileDialogFilterCollection : List<FileDialogFilter> { public string GetFileDialogRepresentation() { return String.Join("|", this.Select(filter => filter.GetFileDialogRepresentation())); } } Usage:
FileDialogFilter filterImage = new FileDialogFilter("Image Files", "*.jpeg", "*.bmp"); FileDialogFilter filterOffice = new FileDialogFilter("Office Files", "*.doc", "*.xls", "*.ppt"); FileDialogFilterCollection filters = new FileDialogFilterCollection { filterImage, filterOffice }; OpenFileDialog fileDialog = new OpenFileDialog { Filter = filters.GetFileDialogRepresentation() }; fileDialog.ShowDialog(); In order to match a list of different categories of file, you can use the filter like this:
var dlg = new Microsoft.Win32.OpenFileDialog() { DefaultExt = ".xlsx", Filter = "Excel Files (*.xls, *.xlsx)|*.xls;*.xlsx|CSV Files (*.csv)|*.csv" }; Use this method to return a Filter compatible string built from ImageCodecInfo supporting image formats the current system understands.
/// <summary> /// Get the Filter string for all supported image types. /// To be used in the FileDialog class Filter Property. /// </summary> /// <returns></returns> public static string GetImageFilter() { string imageExtensions = string.Empty; string separator = ""; ImageCodecInfo[] codecs = ImageCodecInfo.GetImageEncoders(); Dictionary<string, string> imageFilters = new Dictionary<string, string>(); foreach (ImageCodecInfo codec in codecs) { imageExtensions = $"{imageExtensions}{separator}{codec.FilenameExtension.ToLower()}"; separator = ";"; imageFilters.Add($"{codec.FormatDescription} files ({codec.FilenameExtension.ToLower()})", codec.FilenameExtension.ToLower()); } string result = string.Empty; separator = ""; foreach (KeyValuePair<string, string> filter in imageFilters) { result += $"{separator}{filter.Key}|{filter.Value}"; separator = "|"; } if (!string.IsNullOrEmpty(imageExtensions)) { result += $"{separator}Image files|{imageExtensions}"; } return result; } Will result as shown:
This is extreme, but I built a dynamic, database-driven filter using a 2 column database table named FILE_TYPES, with field names EXTENSION and DOCTYPE:
--------------------------------- | EXTENSION | DOCTYPE | --------------------------------- | .doc | Document | | .docx | Document | | .pdf | Document | | ... | ... | | .bmp | Image | | .jpg | Image | | ... | ... | --------------------------------- Obviously I had many different types and extensions, but I'm simplifying it for this example. Here is my function:
private static string GetUploadFilter() { // Desired format: // "Document files (*.doc, *.docx, *.pdf)|*.doc;*.docx;*.pdf|" // "Image files (*.bmp, *.jpg)|*.bmp;*.jpg|" string filter = String.Empty; string nameFilter = String.Empty; string extFilter = String.Empty; // Used to get extensions DataTable dt = new DataTable(); dt = DataLayer.Get_DataTable("SELECT * FROM FILE_TYPES ORDER BY EXTENSION"); // Used to cycle through doctype groupings ("Images", "Documents", etc.) DataTable dtDocTypes = new DataTable(); dtDocTypes = DataLayer.Get_DataTable("SELECT DISTINCT DOCTYPE FROM FILE_TYPES ORDER BY DOCTYPE"); // For each doctype grouping... foreach (DataRow drDocType in dtDocTypes.Rows) { nameFilter = drDocType["DOCTYPE"].ToString() + " files ("; // ... add its associated extensions foreach (DataRow dr in dt.Rows) { if (dr["DOCTYPE"].ToString() == drDocType["DOCTYPE"].ToString()) { nameFilter += "*" + dr["EXTENSION"].ToString() + ", "; extFilter += "*" + dr["EXTENSION"].ToString() + ";"; } } // Remove endings put in place in case there was another to add, and end them with pipe characters: nameFilter = nameFilter.TrimEnd(' ').TrimEnd(','); nameFilter += ")|"; extFilter = extFilter.TrimEnd(';'); extFilter += "|"; // Add the name and its extensions to our main filter filter += nameFilter + extFilter; extFilter = ""; // clear it for next round; nameFilter will be reset to the next DOCTYPE on next pass } filter = filter.TrimEnd('|'); return filter; } private void UploadFile(string fileType, object sender) { Microsoft.Win32.OpenFileDialog dlg = new Microsoft.Win32.OpenFileDialog(); string filter = GetUploadFilter(); dlg.Filter = filter; if (dlg.ShowDialog().Value == true) { string fileName = dlg.FileName; System.IO.FileStream fs = System.IO.File.OpenRead(fileName); byte[] array = new byte[fs.Length]; // This will give you just the filename fileName = fileName.Split('\\')[fileName.Split('\\').Length - 1]; ... Should yield a filter that looks like this:
You must include all image type extensions and allow for all files as an option.
All Files|.|All images|.jpg;.jpeg;.png;.gif;.tif;.bmp|JPEG Images|.jpg|PNG Images|.png";
