微软.net精简框架常见问题及回答(中文版)(18)
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 'MEMORYSTATUS
<DllImport("coredll.dll")> _
Private Shared Sub GlobalMemoryStatus(ByRef ms As MEMORYSTATUS)
End Sub
<DllImport("CoreDll.dll")> _
Public Shared Function GetSystemMemoryDivision( _
ByRef lpdwStorePages As UInt32, _
ByRef lpdwRamPages As UInt32, _
ByRef lpdwPageSize As UInt32) As Integer
End Function
Public Shared Sub Test()
Dim storePages As UInt32
Dim ramPages As UInt32
Dim pageSize As UInt32
Dim res As Integer = GetSystemMemoryDivision(storePages, ramPages, pageSize)
Dim memStatus As New MEMORYSTATUS
GlobalMemoryStatus(memStatus)
End Sub 'Test
6.6. 如何是窗口一直保持最小化？
继承窗体的OnGotFocus方法。
找到窗体的窗口句柄。
调用ShowWindow(hwnd, SW_MINIMIZE)强制窗体最小化。 //C#
using System.Runtime.InteropServices;
[DllImport("CoreDll")]
public static extern IntPtr FindWindow(string className,string WindowsName);
[DllImport("CoreDll")]
public static extern bool ShowWindow(IntPtr hwnd,int nCmdShow);
const int SW_MINIMIZE = 6;
protected override void OnGotFocus(EventArgs e)
{
IntPtr hwnd = FindWindow(null, this.Text);
ShowWindow(hwnd, SW_MINIMIZE);
base.OnGotFocus(e);
}
'VB
Imports System.Runtime.InteropServices
<DllImport("CoreDll")> _
Public Shared Function FindWindow(ByVal className As String, ByVal WindowsName As String) As IntPtr
End Function
<DllImport("CoreDll")> _
Public Shared Function ShowWindow(ByVal hwnd As IntPtr,ByVal nCmdShow As Integer) As Boolean
End Function
Private Const SW_MINIMIZE As Integer = 6
Protected Overrides Sub OnGotFocus(ByVal e As EventArgs)
Dim hwnd As IntPtr = FindWindow(Nothing, Me.Text)
ShowWindow(hwnd, SW_MINIMIZE)
MyBase.OnGotFocus(e)
End Sub 'OnGotFocus
6.7. 在微软.net精简框架上调用系统函数时，如何装配数据类型？
见本问答的 "6.1. 如何调用本地写的ＤＬＬ中的函数？ " 章节。
6.8. 如何得到一个窗体或控件的句柄 (HWND) ？
其实有一些使用调用本地代码的方法可以获得控件的句柄HWND。下面列出其中两种，一种使用GetCapture，另一个使用FindWindow。 //C#
[DllImport("coredll.dll"]
public static extern IntPtr GetCapture();
[DllImport("coredll.dll")]
public static extern IntPtr FindWindow(String lpClassName, String lpWindowName);
this.Text = "FindMe";
IntPtr hwnd1 = FindWindow(null, "FindMe");
this.Capture = true;
IntPtr hwnd2 = GetCapture();
this.Capture = false;
'VB
<DllImport("coredll.dll", SetLastError:=True)> _
Public Shared Function GetCapture() As IntPtr
End Function
<DllImport("coredll.dll", SetLastError:=True)> _
Public Shared Function FindWindow(ByVal lpClassName As String, ByVal lpWindowName As String) As IntPtr
End Function