我有这个代码,我怎么能让它接受所有典型的图像格式?Png, jpeg, jpg, gif ?
以下是我目前所了解到的:
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. :)
}
}
注意,过滤器被设置为.txt文件。我可以更改为PNG,但其他类型呢?
完整的c#解决方案在这里:
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
}
}
这是极端的,但是我使用名为FILE_TYPES的2列数据库表构建了一个动态的、数据库驱动的过滤器,字段名为EXTENSION和DOCTYPE:
---------------------------------
| EXTENSION | DOCTYPE |
---------------------------------
| .doc | Document |
| .docx | Document |
| .pdf | Document |
| ... | ... |
| .bmp | Image |
| .jpg | Image |
| ... | ... |
---------------------------------
显然,我有许多不同的类型和扩展,但在本例中我将其简化。这是我的函数:
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];
...
应该生成如下所示的过滤器:
只是一个关于使用字符串的necrocomment。Join和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()));