blocks|key|3068748|text|在the+docs中，您需要的筛选器语法如下：|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|3068749|Office+Files%7C*.doc;*.xls;*.ppt|code-block|syntax|javascript|3068750|即用分号分隔多个扩展名--因此，Image+Files%7C*.jpg;*.jpeg;*.png;...。|style|CODE|3068751|entityMap|0|LINK|mutability|MUTABLE|url|https://docs.microsoft.com/en-us/dotnet/api/microsoft.win32.filedialog.filter^0|1|8|0|0|0|G|Y|0^^$0|@$1|2|3|4|5|6|7|U|8|@]|9|@$A|V|B|W|1|X]]|C|$]]|$1|D|3|E|5|F|7|Y|8|@]|9|@]|C|$G|H]]|$1|I|3|J|5|6|7|Z|8|@$A|10|B|11|K|L]]|9|@]|C|$]]|$1|M|3|-4|5|6|7|12|8|@]|9|@]|C|$]]]|N|$O|$5|P|Q|R|C|$S|T]]]]

From <a href="https://docs.microsoft.com/en-us/dotnet/api/microsoft.win32.filedialog.filter" rel="noreferrer">the docs</a>, the filter syntax that you need is as follows:

<pre><code>Office Files|*.doc;*.xls;*.ppt
</code></pre>

i.e. separate the multiple extensions with a semicolon -- thus, <code>Image Files|*.jpg;*.jpeg;*.png;...</code>.

blocks|key|317994|text|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。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|317995|ImageCodecInfo[]+codecs+=+ImageCodecInfo.GetImageEncoders();|code-block|syntax|javascript|317996|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

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.

<pre><code>ImageCodecInfo[] codecs = ImageCodecInfo.GetImageEncoders();
</code></pre>

blocks|key|322821|text|以下是ImageCodecInfo建议的示例(在VB中)：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|322822|+++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})%7C{3}",+ofd.Filter,+sep,+codecName,+c.FilenameExtension)
++++++++++++sep+=+"%7C"
++++++++Next
++++++++ofd.Filter+=+String.Format("{0}{1}{2}+({3})%7C{3}",+ofd.Filter,+sep,+"All+Files",+"*.*")|code-block|syntax|javascript|322823|它看起来像这样：|322824|​|322825|📷|atomic|offset|length|322826|322827|entityMap|0|IMAGE|mutability|IMMUTABLE|imageUrl|https://ask.qcloudimg.com/http-save/yehe-900000/4cf7306e4b02952162df8b140aa34278.png|imageAlt^0|0|0|0|0|0|1|0|0|0^^$0|@$1|2|3|4|5|6|7|Z|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|10|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|11|8|@]|9|@]|A|$]]|$1|I|3|J|5|6|7|12|8|@]|9|@]|A|$]]|$1|K|3|L|5|M|7|13|8|@]|9|@$N|14|O|15|1|16]]|A|$]]|$1|P|3|J|5|6|7|17|8|@]|9|@]|A|$]]|$1|Q|3|-4|5|6|7|18|8|@]|9|@]|A|$]]]|R|$S|$5|T|U|V|A|$W|X|Y|-4]]]]

Here's an example of the ImageCodecInfo suggestion (in VB):

<pre><code> 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", "*.*")
</code></pre>

And it looks like this:

<img src="https://i.stack.imgur.com/TldMy.png" alt="enter image description here">

blocks|key|320849|text|C#中的完整解决方案在这里：|type|unstyled|depth|inlineStyleRanges|offset|length|style|BOLD|entityRanges|data|320850|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})%7C{3}",+dlg.Filter,+sep,+codecName,+c.FilenameExtension);
+++++++sep+=+"%7C";
++++}

++++dlg.Filter+=+String.Format("{0}{1}{2}+({3})%7C{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++
++++}
}+|code-block|syntax|javascript|320851|entityMap^0|4|A|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@$9|N|A|O|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|P|8|@]|D|@]|E|$I|J]]|$1|K|3|-4|5|6|7|Q|8|@]|D|@]|E|$]]]|L|$]]

Complete solution in C# is here:

<pre><code>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&lt;bool&gt; result = dlg.ShowDialog();

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

blocks|key|3068773|text|若要筛选图像文件，请使用此代码示例。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3068774|//Create+a+new+instance+of+openFileDialog
OpenFileDialog+res+=+new+OpenFileDialog();

//Filter
res.Filter+=+"Image+Files%7C*.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
+++....
}|code-block|syntax|javascript|3068775|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

To filter images files, use this code sample.

<pre><code>//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
 ....
}
</code></pre>

blocks|key|322832|text|只是对使用string.Join和LINQ的一个简单的评论。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|322833|ImageCodecInfo[]+codecs+=+ImageCodecInfo.GetImageEncoders();
dlgOpenMockImage.Filter+=+string.Format("{0}%7C+All+image+files+({1})%7C{1}%7CAll+files%7C*",+
++++string.Join("%7C",+codecs.Select(codec+=>+
++++string.Format("{0}+({1})%7C{1}",+codec.CodecName,+codec.FilenameExtension)).ToArray()),
++++string.Join(";",+codecs.Select(codec+=>+codec.FilenameExtension).ToArray()));|code-block|syntax|javascript|322834|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

Just a necrocomment for using string.Join and LINQ.

<pre><code>ImageCodecInfo[] codecs = ImageCodecInfo.GetImageEncoders();
dlgOpenMockImage.Filter = string.Format("{0}| All image files ({1})|{1}|All files|*", 
 string.Join("|", codecs.Select(codec =&gt; 
 string.Format("{0} ({1})|{1}", codec.CodecName, codec.FilenameExtension)).ToArray()),
 string.Join(";", codecs.Select(codec =&gt; codec.FilenameExtension).ToArray()));
</code></pre>

blocks|key|319856|text|对于那些不想每次都记住语法的人，这里有一个简单的封装：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|319857|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("%7C");
++++++++builder.Append(String.Join(";",+this));

++++++++return+builder.ToString();
++++}
}

public+class+FileDialogFilterCollection+:+List<FileDialogFilter>
{
++++public+string+GetFileDialogRepresentation()
++++{
++++++++return+String.Join("%7C",+this.Select(filter+=>+filter.GetFileDialogRepresentation()));
++++}
}|code-block|syntax|javascript|319858|用法：|319859|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();|319860|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

For those who don't want to remember the syntax everytime here is a simple encapsulation:

<pre><code>public class FileDialogFilter : List&lt;string&gt;
{
 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&lt;FileDialogFilter&gt;
{
 public string GetFileDialogRepresentation()
 {
 return String.Join("|", this.Select(filter =&gt; filter.GetFileDialogRepresentation()));
 }
}
</code></pre>

Usage:

<pre><code>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();
</code></pre>

blocks|key|320864|text|我最喜欢汤姆·浮士德的答案。这是他的解决方案的C#版本，但稍微简化了一些。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|320865|var+codecs+=+ImageCodecInfo.GetImageEncoders();+
var+codecFilter+=+"Image+Files%7C";+
foreach+(var+codec+in+codecs)+
{
++++codecFilter+%2B=+codec.FilenameExtension+%2B+";";+
}+
dialog.Filter+=+codecFilter;|code-block|syntax|javascript|320866|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

I like Tom Faust's answer the best. Here's a C# version of his solution, but simplifying things a bit.

<pre><code>var codecs = ImageCodecInfo.GetImageEncoders(); 
var codecFilter = "Image Files|"; 
foreach (var codec in codecs) 
{
 codecFilter += codec.FilenameExtension + ";"; 
} 
dialog.Filter = codecFilter;
</code></pre>

blocks|key|3281859|text|这很极端，但我使用一个名为FILE_TYPES的两列数据库表构建了一个动态的、数据库驱动的过滤器，其字段名为EXTENSION和DOCTYPE：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3281860|---------------------------------
%7C+EXTENSION++%7C++DOCTYPE+++++++++%7C
---------------------------------
%7C+++.doc+++++%7C++Document++++++++%7C
%7C+++.docx++++%7C++Document++++++++%7C
%7C+++.pdf+++++%7C++Document++++++++%7C
%7C+++...++++++%7C++...+++++++++++++%7C
%7C+++.bmp+++++%7C++Image+++++++++++%7C
%7C+++.jpg+++++%7C++Image+++++++++++%7C
%7C+++...++++++%7C++...+++++++++++++%7C
---------------------------------|code-block|syntax|javascript|3281861|显然，我有许多不同的类型和扩展，但我在本例中对其进行了简化。下面是我的函数：|3281862|++++private+static+string+GetUploadFilter()
++++{
++++++++//+Desired+format:
++++++++//+"Document+files+(*.doc,+*.docx,+*.pdf)%7C*.doc;*.docx;*.pdf%7C"
++++++++//+"Image+files+(*.bmp,+*.jpg)%7C*.bmp;*.jpg%7C"

++++++++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()+%2B+"+files+(";

++++++++++++//+...+add+its+associated+extensions
++++++++++++foreach+(DataRow+dr+in+dt.Rows)
++++++++++++{
++++++++++++++++if+(dr["DOCTYPE"].ToString()+==+drDocType["DOCTYPE"].ToString())
++++++++++++++++{
++++++++++++++++++++nameFilter+%2B=+"*"+%2B+dr["EXTENSION"].ToString()+%2B+",+";
++++++++++++++++++++extFilter+%2B=+"*"+%2B+dr["EXTENSION"].ToString()+%2B+";";
++++++++++++++++}++++++++++++++++++++
++++++++++++}

++++++++++++//+Remove+endings+put+in+place+in+case+there+was+another+to+add,+and+end+them+with+pipe+characters:
++++++++++++nameFilter+=+nameFilter.TrimEnd('+').TrimEnd(',');
++++++++++++nameFilter+%2B=+")%7C";
++++++++++++extFilter+=+extFilter.TrimEnd(';');
++++++++++++extFilter+%2B=+"%7C";

++++++++++++//+Add+the+name+and+its+extensions+to+our+main+filter
++++++++++++filter+%2B=+nameFilter+%2B+extFilter;

++++++++++++extFilter+=+"";+//+clear+it+for+next+round;+nameFilter+will+be+reset+to+the+next+DOCTYPE+on+next+pass
++++++++}

++++++++filter+=+filter.TrimEnd('%7C');
++++++++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];
++++++++++++...|3281863|应该会产生一个如下所示的过滤器：|3281864|​|3281865|📷|atomic|offset|length|3281866|3281867|entityMap|0|IMAGE|mutability|IMMUTABLE|imageUrl|https://ask.qcloudimg.com/http-save/yehe-900000/a9716a08ffa84e3fdce5236700858a25.png|imageAlt^0|0|0|0|0|0|0|0|1|0|0|0^^$0|@$1|2|3|4|5|6|7|13|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|14|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|15|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|16|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|17|8|@]|9|@]|A|$]]|$1|M|3|N|5|6|7|18|8|@]|9|@]|A|$]]|$1|O|3|P|5|Q|7|19|8|@]|9|@$R|1A|S|1B|1|1C]]|A|$]]|$1|T|3|N|5|6|7|1D|8|@]|9|@]|A|$]]|$1|U|3|-4|5|6|7|1E|8|@]|9|@]|A|$]]]|V|$W|$5|X|Y|Z|A|$10|11|12|-4]]]]

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:

<pre><code>---------------------------------
| EXTENSION | DOCTYPE |
---------------------------------
| .doc | Document |
| .docx | Document |
| .pdf | Document |
| ... | ... |
| .bmp | Image |
| .jpg | Image |
| ... | ... |
---------------------------------
</code></pre>

Obviously I had many different types and extensions, but I'm simplifying it for this example. Here is my function:

<pre><code> 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];
 ...
</code></pre>

Should yield a filter that looks like this:

<a href="https://i.stack.imgur.com/hhNMp.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/hhNMp.png" alt="enter image description here"></a>

blocks|key|3068795|text|为了匹配不同类别的文件列表，您可以像这样使用过滤器：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3068796|++++++++var+dlg+=+new+Microsoft.Win32.OpenFileDialog()
++++++++{
++++++++++++DefaultExt+=+".xlsx",
++++++++++++Filter+=+"Excel+Files+(*.xls,+*.xlsx)%7C*.xls;*.xlsx%7CCSV+Files+(*.csv)%7C*.csv"
++++++++};|code-block|syntax|javascript|3068797|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

In order to match a list of different categories of file, you can use the filter like this:

<pre><code> var dlg = new Microsoft.Win32.OpenFileDialog()
 {
 DefaultExt = ".xlsx",
 Filter = "Excel Files (*.xls, *.xlsx)|*.xls;*.xlsx|CSV Files (*.csv)|*.csv"
 };
</code></pre>

blocks|key|3068799|text|您必须包含所有图像类型扩展名，并允许所有文件作为选项。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3068800|所有文件%7C.%7C+All+images%7C.jpg;.jpeg;.png;.gif;.tif;.bmp%7CJPEG+Images%7C.jpg%7CPNG+Images%7C.png"；|3068801|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|F|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|G|8|@]|9|@]|A|$]]|$1|D|3|-4|5|6|7|H|8|@]|9|@]|A|$]]]|E|$]]

blocks|key|3281895|text|使用此方法返回从支持当前系统识别的图像格式的ImageCodecInfo生成的筛选器兼容字符串。|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|3281896|++++++++///+<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+%2B=+$"{separator}{filter.Key}%7C{filter.Value}";
++++++++++++++++separator+=+"%7C";
++++++++++++}
++++++++++++if+(!string.IsNullOrEmpty(imageExtensions))
++++++++++++{
++++++++++++++++result+%2B=+$"{separator}Image+files%7C{imageExtensions}";
++++++++++++}
++++++++++++return+result;
++++++++}|code-block|syntax|javascript|3281897|结果如下所示：|3281898|​|3281899|📷|atomic|3281900|3281901|entityMap|0|LINK|mutability|MUTABLE|url|https://docs.microsoft.com/en-us/dotnet/api/system.drawing.imaging.imagecodecinfo|1|IMAGE|IMMUTABLE|imageUrl|https://ask.qcloudimg.com/http-save/yehe-900000/d4188327b77082861362ded621808965.png|imageAlt^0|M|E|0|0|0|0|0|0|1|1|0|0^^$0|@$1|2|3|4|5|6|7|14|8|@]|9|@$A|15|B|16|1|17]]|C|$]]|$1|D|3|E|5|F|7|18|8|@]|9|@]|C|$G|H]]|$1|I|3|J|5|6|7|19|8|@]|9|@]|C|$]]|$1|K|3|L|5|6|7|1A|8|@]|9|@]|C|$]]|$1|M|3|N|5|O|7|1B|8|@]|9|@$A|1C|B|1D|1|1E]]|C|$]]|$1|P|3|L|5|6|7|1F|8|@]|9|@]|C|$]]|$1|Q|3|-4|5|6|7|1G|8|@]|9|@]|C|$]]]|R|$S|$5|T|U|V|C|$W|X]]|Y|$5|Z|U|10|C|$11|12|13|-4]]]]

Use this method to return a Filter compatible string built from <a href="https://docs.microsoft.com/en-us/dotnet/api/system.drawing.imaging.imagecodecinfo" rel="nofollow noreferrer">ImageCodecInfo</a> supporting image formats the current system understands.
<pre><code> /// &lt;summary&gt;
 /// Get the Filter string for all supported image types.
 /// To be used in the FileDialog class Filter Property.
 /// &lt;/summary&gt;
 /// &lt;returns&gt;&lt;/returns&gt;
 public static string GetImageFilter()
 {
 string imageExtensions = string.Empty;
 string separator = &quot;&quot;;
 ImageCodecInfo[] codecs = ImageCodecInfo.GetImageEncoders();
 Dictionary&lt;string, string&gt; imageFilters = new Dictionary&lt;string, string&gt;();
 foreach (ImageCodecInfo codec in codecs)
 {
 imageExtensions = $&quot;{imageExtensions}{separator}{codec.FilenameExtension.ToLower()}&quot;;
 separator = &quot;;&quot;;
 imageFilters.Add($&quot;{codec.FormatDescription} files ({codec.FilenameExtension.ToLower()})&quot;, codec.FilenameExtension.ToLower());
 }
 string result = string.Empty;
 separator = &quot;&quot;;
 foreach (KeyValuePair&lt;string, string&gt; filter in imageFilters)
 {
 result += $&quot;{separator}{filter.Key}|{filter.Value}&quot;;
 separator = &quot;|&quot;;
 }
 if (!string.IsNullOrEmpty(imageExtensions))
 {
 result += $&quot;{separator}Image files|{imageExtensions}&quot;;
 }
 return result;
 }
</code></pre>
Will result as shown:
<a href="https://i.stack.imgur.com/2fGNJ.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/2fGNJ.png" alt="Dialog Filter" /></a>

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:

<pre><code>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. :)
 } 
}
</code></pre>

Notice that the filter is set to .txt files. I could change to PNG, but what of the other types?

Setting the filter to an OpenFileDialog to allow the typical image formats?

数据库

我有这个代码，我怎么能让它接受所有典型的图像格式呢？PNG、JPEG、JPG、GIF？这是我到目前为止所知道的：public void EncryptFile(){                OpenFileDialog dialog = new OpenFileDialog();    dialog.Filter...

问将过滤器设置为OpenFileDialog以允许典型的图像格式？
EN

社区

活动

资源

关于

腾讯云开发者

热门产品

热门推荐

更多推荐

问将过滤器设置为OpenFileDialog以允许典型的图像格式？EN

社区

活动

资源

关于

腾讯云开发者

热门产品

热门推荐

更多推荐

问将过滤器设置为OpenFileDialog以允许典型的图像格式？
EN