HOW TO：擷取與 Windows Form 中檔案相關的圖示
許多檔案都有可提供相關聯檔案類型之視覺表示的內嵌圖示。 例如，Microsoft Word 文件就包含可將其識別為 Word 文件的圖示。 在清單控制項或表格控制項中顯示檔案時，您必須在每個檔案名稱的旁邊顯示代表檔案類型的圖示。 這時您只要使用 ExtractAssociatedIcon 方法，便可輕易完成這個動作。
範例
下列程式碼範例會示範如何擷取與檔案關聯的圖示，並在 ListView 控制項中顯示檔案名稱及其關聯的圖示。
Private listView1 As ListView
Private imageList1 As ImageList
Public Sub ExtractAssociatedIconEx()
' Initialize the ListView, ImageList and Form.
listView1 = New ListView()
imageList1 = New ImageList()
listView1.Location = New Point(37, 12)
listView1.Size = New Size(161, 242)
listView1.SmallImageList = imageList1
listView1.View = View.SmallIcon
Me.ClientSize = New System.Drawing.Size(292, 266)
Me.Controls.Add(Me.listView1)
Me.Text = "Form1"
' Get the c:\ directory.
Dim dir As New System.IO.DirectoryInfo("c:\")
Dim item As ListViewItem
listView1.BeginUpdate()
Dim file As System.IO.FileInfo
For Each file In dir.GetFiles()
' Set a default icon for the file.
Dim iconForFile As Icon = SystemIcons.WinLogo
item = New ListViewItem(file.Name, 1)
' Check to see if the image collection contains an image
' for this extension, using the extension as a key.
If Not (imageList1.Images.ContainsKey(file.Extension)) Then
' If not, add the image to the image list.
iconForFile = System.Drawing.Icon.ExtractAssociatedIcon(file.FullName)
imageList1.Images.Add(file.Extension, iconForFile)
End If
item.ImageKey = file.Extension
listView1.Items.Add(item)
Next file
listView1.EndUpdate()
End Sub
ListView listView1;
ImageList imageList1;
public void ExtractAssociatedIconEx()
{
// Initialize the ListView, ImageList and Form.
listView1 = new ListView();
imageList1 = new ImageList();
listView1.Location = new Point(37, 12);
listView1.Size = new Size(151, 262);
listView1.SmallImageList = imageList1;
listView1.View = View.SmallIcon;
this.ClientSize = new System.Drawing.Size(292, 266);
this.Controls.Add(this.listView1);
this.Text = "Form1";
// Get the c:\ directory.
System.IO.DirectoryInfo dir = new System.IO.DirectoryInfo(@"c:\");
ListViewItem item;
listView1.BeginUpdate();
// For each file in the c:\ directory, create a ListViewItem
// and set the icon to the icon extracted from the file.
foreach (System.IO.FileInfo file in dir.GetFiles())
{
// Set a default icon for the file.
Icon iconForFile = SystemIcons.WinLogo;
item = new ListViewItem(file.Name, 1);
iconForFile = Icon.ExtractAssociatedIcon(file.FullName);
// Check to see if the image collection contains an image
// for this extension, using the extension as a key.
if (!imageList1.Images.ContainsKey(file.Extension))
{
// If not, add the image to the image list.
iconForFile = System.Drawing.Icon.ExtractAssociatedIcon(file.FullName);
imageList1.Images.Add(file.Extension, iconForFile);
}
item.ImageKey = file.Extension;
listView1.Items.Add(item);
}
listView1.EndUpdate();
}
編譯程式碼
若要編譯此範例：
將先前的程式碼貼入 Windows Form，並從表單的建構函式或 Load 事件處理方法呼叫 ExtractAssociatedIconExample 方法。
您將需要確定您的表單有匯入 System.IO 命名空間 (Namespace)。