Comment : obtenir la mémoire d'un périphérique

Article
08/21/2008

Mise à jour : novembre 2007

Pour obtenir la mémoire disponible d'un périphérique, utilisez l'appel de code non managé pour appeler les fonctions GlobalMemoryStatus et GetSystemMemoryDivision natives.

Exemple

Cet exemple de code définit les éléments suivants :

Déclarations d'appel de code non managé pour les méthodes natives dans Windows Embedded CE.
Une structure permettant d'échanger avec les méthodes natives.
Une méthode managée nommée ShowMemory qui affiche la mémoire disponible.

Public Structure MEMORYSTATUS
    Public dwLength As UInt32
    Public dwMemoryLoad As UInt32
    Public dwTotalPhys As UInt32
    Public dwAvailPhys As UInt32
    Public dwTotalPageFile As UInt32
    Public dwAvailPageFile As UInt32
    Public dwTotalVirtual As UInt32
    Public dwAvailVirtual As UInt32
End Structure 

Public Declare Function GlobalMemoryStatus Lib "CoreDll.Dll" _
    (ByRef ms As MEMORYSTATUS) As Integer

Public Declare Function GetSystemMemoryDivision Lib "CoreDll.Dll" _
    (ByRef lpdwStorePages As UInt32, _
    ByRef ldpwRamPages As UInt32, _
    ByRef ldpwPageSize As UInt32) As Integer

Public Shared Sub ShowMemory()
    Dim storePages As UInt32
    Dim ramPages As UInt32
    Dim pageSize As UInt32
    Dim res As Integer = _
        GetSystemMemoryDivision(storePages, ramPages, pageSize)

    ' Call the native GlobalMemoryStatus method
    ' with the defined structure.
    Dim memStatus As New MEMORYSTATUS
    GlobalMemoryStatus(memStatus)

  ' Use a StringBuilder for the message box string.
    Dim MemoryInfo As New StringBuilder
    MemoryInfo.Append("Memory Load: " _
        & memStatus.dwMemoryLoad.ToString() & vbCrLf)
    MemoryInfo.Append("Total Physical: " _
        & memStatus.dwTotalPhys.ToString() & vbCrLf)
    MemoryInfo.Append("Avail Physical: " _
        & memStatus.dwAvailPhys.ToString() & vbCrLf)
    MemoryInfo.Append("Total Page File: " _
        & memStatus.dwTotalPageFile.ToString() & vbCrLf)
    MemoryInfo.Append("Avail Page File: " _
        & memStatus.dwAvailPageFile.ToString() & vbCrLf)
    MemoryInfo.Append("Total Virtual: " _
        & memStatus.dwTotalVirtual.ToString() & vbCrLf)
    MemoryInfo.Append("Avail Virtual: " _
        & memStatus.dwAvailVirtual.ToString() & vbCrLf)

    ' Show the available memory.
    MessageBox.Show(MemoryInfo.ToString())  

End Sub

public struct MEMORYSTATUS
{
    public UInt32 dwLength;
    public UInt32 dwMemoryLoad;
    public UInt32 dwTotalPhys;
    public UInt32 dwAvailPhys;
    public UInt32 dwTotalPageFile;
    public UInt32 dwAvailPageFile;
    public UInt32 dwTotalVirtual;
    public UInt32 dwAvailVirtual;
}

[DllImport("CoreDll.dll")]
public static extern void GlobalMemoryStatus
(
    ref MEMORYSTATUS lpBuffer
);

[DllImport("CoreDll.dll")]
public static extern int GetSystemMemoryDivision
(
    ref UInt32 lpdwStorePages,
    ref UInt32 lpdwRamPages,
    ref UInt32 lpdwPageSize
);

public void ShowMemory()
{
    UInt32 storePages = 0;
    UInt32 ramPages = 0;
    UInt32 pageSize = 0;
    int res = GetSystemMemoryDivision(ref storePages, 
        ref ramPages, ref pageSize);

    // Call the native GlobalMemoryStatus method
    // with the defined structure.
    MEMORYSTATUS memStatus = new MEMORYSTATUS();
    GlobalMemoryStatus(ref memStatus);

    // Use a StringBuilder for the message box string.
    StringBuilder MemoryInfo = new StringBuilder();
    MemoryInfo.Append("Memory Load: " 
        + memStatus.dwMemoryLoad.ToString() + "\n");
    MemoryInfo.Append("Total Physical: " 
        + memStatus.dwTotalPhys.ToString() + "\n");
    MemoryInfo.Append("Avail Physical: " 
        + memStatus.dwAvailPhys.ToString() + "\n");
    MemoryInfo.Append("Total Page File: " 
        + memStatus.dwTotalPageFile.ToString() + "\n");
    MemoryInfo.Append("Avail Page File: " 
        + memStatus.dwAvailPageFile.ToString() + "\n");
    MemoryInfo.Append("Total Virtual: " 
        + memStatus.dwTotalVirtual.ToString() + "\n");
    MemoryInfo.Append("Avail Virtual: " 
        + memStatus.dwAvailVirtual.ToString() + "\n");

    // Show the available memory.
    MessageBox.Show(MemoryInfo.ToString());

}

Compilation du code

Cet exemple nécessite des références aux espaces de noms suivants :

Voir aussi

Tâches

Comment : obtenir l'ID et le nom du périphérique

Autres ressources

Interopérabilité dans le .NET Compact Framework

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