Anvisningar: Lista installerade avkodare

Du kanske vill visa en lista över de bildavkodare som är tillgängliga på en dator för att avgöra om programmet kan läsa ett visst bildfilformat. Klassen ImageCodecInfo innehåller GetImageDecoders statiska metoder så att du kan avgöra vilka bilddekodare som är tillgängliga. GetImageDecoders returnerar en matris med ImageCodecInfo objekt.

Exempel

I följande kodexempel visas listan över installerade avkodare och deras egenskapsvärden.

private void GetImageDecodersExample(PaintEventArgs e)
{
    // Get an array of available decoders.
    ImageCodecInfo[] myCodecs;
    myCodecs = ImageCodecInfo.GetImageDecoders();
    int numCodecs = myCodecs.GetLength(0);

    // Set up display variables.
    Color foreColor = Color.Black;
    Font font = new Font("Arial", 8);
    int i = 0;

    // Check to determine whether any codecs were found.
    if (numCodecs > 0)
    {
        // Set up an array to hold codec information. There are 9
        // information elements plus 1 space for each codec, so 10 times
        // the number of codecs found is allocated.
        string[] myCodecInfo = new string[numCodecs * 10];

        // Write all the codec information to the array.
        for (i = 0; i < numCodecs; i++)
        {
            myCodecInfo[i * 10] = "Codec Name = " + myCodecs[i].CodecName;
            myCodecInfo[(i * 10) + 1] = "Class ID = " +
                myCodecs[i].Clsid.ToString();
            myCodecInfo[(i * 10) + 2] = "DLL Name = " + myCodecs[i].DllName;
            myCodecInfo[(i * 10) + 3] = "Filename Ext. = " +
                myCodecs[i].FilenameExtension;
            myCodecInfo[(i * 10) + 4] = "Flags = " +
                myCodecs[i].Flags.ToString();
            myCodecInfo[(i * 10) + 5] = "Format Descrip. = " +
                myCodecs[i].FormatDescription;
            myCodecInfo[(i * 10) + 6] = "Format ID = " +
                myCodecs[i].FormatID.ToString();
            myCodecInfo[(i * 10) + 7] = "MimeType = " + myCodecs[i].MimeType;
            myCodecInfo[(i * 10) + 8] = "Version = " +
                myCodecs[i].Version.ToString();
            myCodecInfo[(i * 10) + 9] = " ";
        }
        int numMyCodecInfo = myCodecInfo.GetLength(0);

        // Render all of the information to the screen.
        int j = 20;
        for (i = 0; i < numMyCodecInfo; i++)
        {
            e.Graphics.DrawString(myCodecInfo[i],
                font,
                new SolidBrush(foreColor),
                20,
                j);
            j += 12;
        }
    }
    else
        e.Graphics.DrawString("No Codecs Found",
            font,
            new SolidBrush(foreColor),
            20,
            20);
}
Private Sub GetImageDecodersExample(ByVal e As PaintEventArgs)
    ' Get an array of available decoders.
    Dim myCodecs() As ImageCodecInfo
    myCodecs = ImageCodecInfo.GetImageDecoders()
    Dim numCodecs As Integer = myCodecs.GetLength(0)

    ' Set up display variables.
    Dim foreColor As Color = Color.Black
    Dim font As New Font("Arial", 8)
    Dim i As Integer = 0

    ' Check to determine whether any codecs were found.
    If numCodecs > 0 Then
        ' Set up an array to hold codec information. There are 9
        ' information elements plus 1 space for each codec, so 10 times
        ' the number of codecs found is allocated.
        Dim myCodecInfo(numCodecs * 10) As String

        ' Write all the codec information to the array.
        For i = 0 To numCodecs - 1
            myCodecInfo((i * 10)) = "Codec Name = " + myCodecs(i).CodecName
            myCodecInfo((i * 10 + 1)) = "Class ID = " + myCodecs(i).Clsid.ToString()
            myCodecInfo((i * 10 + 2)) = "DLL Name = " + myCodecs(i).DllName
            myCodecInfo((i * 10 + 3)) = "Filename Ext. = " + myCodecs(i).FilenameExtension
            myCodecInfo((i * 10 + 4)) = "Flags = " + myCodecs(i).Flags.ToString()
            myCodecInfo((i * 10 + 5)) = "Format Descrip. = " + myCodecs(i).FormatDescription
            myCodecInfo((i * 10 + 6)) = "Format ID = " + myCodecs(i).FormatID.ToString()
            myCodecInfo((i * 10 + 7)) = "MimeType = " + myCodecs(i).MimeType
            myCodecInfo((i * 10 + 8)) = "Version = " + myCodecs(i).Version.ToString()
            myCodecInfo((i * 10 + 9)) = " "
        Next i
        Dim numMyCodecInfo As Integer = myCodecInfo.GetLength(0)

        ' Render all of the information to the screen.
        Dim j As Integer = 20
        For i = 0 To numMyCodecInfo - 1
            e.Graphics.DrawString(myCodecInfo(i), _
                font, New SolidBrush(foreColor), 20, j)
            j += 12
        Next i
    Else
        e.Graphics.DrawString("No Codecs Found", _
            font, New SolidBrush(foreColor), 20, 20)
    End If
End Sub

Kompilera koden

Det här exemplet kräver:

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