过滤器设置为一个OpenFileDialog,使典型的图像格式?
-
20-09-2019 - |
题
我有这样的代码,我怎么能允许它接受所有典型的图像格式? PNG,JPEG,JPG,GIF?
这是我到目前为止有:
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. :)
}
}
请注意,所述过滤器被设置为.txt文件。 我可以在其他类型的更改为PNG,但什么?
解决方案
从的文档,所述好需要的过滤器语法如下:
Office Files|*.doc;*.xls;*.ppt
即。所述多个扩展用分号分隔 - 。因此,Image Files|*.jpg;*.jpeg;*.png;...
其他提示
按照这种模式,如果你浏览的图像文件:
dialog.Filter = "Image files (*.jpg, *.jpeg, *.jpe, *.jfif, *.png) | *.jpg; *.jpeg; *.jpe; *.jfif; *.png";
这里的ImageCodecInfo建议(在VB)的示例:
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", "*.*")
和它看起来像这样:
在C#的完整的解决方案是在这里:强>
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
}
}
要过滤的图像文件,使用此代码示例。
//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
....
}
我喜欢汤姆·福斯特的回答是最好的。下面是他的解决方案的C#版本,但简化的东西一点。
var codecs = ImageCodecInfo.GetImageEncoders();
var codecFilter = "Image Files|";
foreach (var codec in codecs)
{
codecFilter += codec.FilenameExtension + ";";
}
dialog.Filter = codecFilter;
有关图像,你可以从GDI(System.Drawing中)获取可用的编解码器和一点点工作,建立从你的列表中。这将是最灵活的方式去了。
ImageCodecInfo[] codecs = ImageCodecInfo.GetImageEncoders();
使用的string.join和LINQ仅有necrocomment。
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()));
对于那些不想在这里记住语法每次谁是一个简单的封装:
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()));
}
}
用法:
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();
在为了匹配不同类别的文件的列表,则可以使用像这样的过滤器:
var dlg = new Microsoft.Win32.OpenFileDialog()
{
DefaultExt = ".xlsx",
Filter = "Excel Files (*.xls, *.xlsx)|*.xls;*.xlsx|CSV Files (*.csv)|*.csv"
};
这是极端,但是我建立使用名为FILE_TYPES一个2列数据库表一个动态的,数据库驱动的过滤器,与字段名EXTENSION和DOCTYPE:
---------------------------------
| EXTENSION | DOCTYPE |
---------------------------------
| .doc | Document |
| .docx | Document |
| .pdf | Document |
| ... | ... |
| .bmp | Image |
| .jpg | Image |
| ... | ... |
---------------------------------
显然,我有很多不同的类型和扩展名,但我简化它的这个例子。这是我的功能:
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];
...
应该产生一个过滤器,看起来像这样:
不隶属于 StackOverflow