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?
当前回答
下面是一个ImageCodecInfo建议的例子(在VB中):
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 = "|"
Next
ofd.Filter = String.Format("{0}{1}{2} ({3})|{3}", ofd.Filter, sep, "All Files", "*.*")
它是这样的:
其他回答
为了匹配一个由不同类别的文件组成的列表，你可以像这样使用过滤器:
var dlg = new Microsoft.Win32.OpenFileDialog()
{
DefaultExt = ".xlsx",
Filter = "Excel Files (*.xls, *.xlsx)|*.xls;*.xlsx|CSV Files (*.csv)|*.csv"
};
下面是一个ImageCodecInfo建议的例子(在VB中):
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 = "|"
Next
ofd.Filter = String.Format("{0}{1}{2} ({3})|{3}", ofd.Filter, sep, "All Files", "*.*")
它是这样的:
我最喜欢汤姆·浮士德的回答。下面是他的解决方案的c#版本，但简化了一些事情。
var codecs = ImageCodecInfo.GetImageEncoders();
var codecFilter = "Image Files|";
foreach (var codec in codecs)
{
codecFilter += codec.FilenameExtension + ";";
}
dialog.Filter = codecFilter;
要过滤图像文件，请使用下面的代码示例。
//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
....
}
对于图像，您可以从GDI (System.Drawing)获得可用的编解码器，并通过一些工作来构建您的列表。这将是最灵活的方式。
ImageCodecInfo[] codecs = ImageCodecInfo.GetImageEncoders();
