1.需要匯入System.Runtime.InteropServices命名空間

2.宣告 ShowWindowAsync 函數

[DllImport("user32.dll")]

PRivatestaticexternboolShowWindowAsync(

IntPtrhWnd,

intnCmdShow

);

3.宣告 ShowWindow函數

[DllImport("user32.dll")]

publicstaticexternintShowWindow(

inthwnd,

intnCmdShow

);

4.宣告API常數定義

//API 常數定義

privateconstintSW_HIDE = 0;

privateconstintSW_NORMAL = 1;

privateconstintSW_MAXIMIZE = 3;

privateconstintSW_SHOWNOACTIVATE = 4;

privateconstintSW_SHOW = 5;

privateconstintSW_MINIMIZE = 6;

privateconstintSW_RESTORE = 9;

privateconstintSW_SHOWDEFAULT = 10;

5.上述函數功能相同，都是用來設定視窗大小，不同的是宣告的型態不一樣需轉型。

ShowWindowAsync(this.Handle, SW_MINIMIZE);

ShowWindow((int)this.Handle, SW_MINIMIZE);

6.若是把int改成IntPtr，使用ShowWindow就不用轉型，所以在宣告時就可以考慮資料型態，必免轉型所耗的資源。

[DllImport("user32.dll")]

publicstaticexternintShowWindow(

inthwnd,

intnCmdShow

);

C#完整範例

usingSystem;

usingSystem.Windows.Forms;

usingSystem.Runtime.InteropServices;

namespaceCS_WindowsResize

{

publicpartialclassForm1:Form

{

publicForm1()

{

InitializeComponent();

}

//API 常數定義

privateconstintSW_HIDE = 0;

privateconstintSW_NORMAL = 1;

privateconstintSW_MAXIMIZE = 3;

privateconstintSW_SHOWNOACTIVATE = 4;

privateconstintSW_SHOW = 5;

privateconstintSW_MINIMIZE = 6;

privateconstintSW_RESTORE = 9;

privateconstintSW_SHOWDEFAULT = 10;

[DllImport("user32.dll")]

privatestaticexternboolShowWindowAsync(

IntPtrhWnd,

intnCmdShow

);

[DllImport("user32.dll")]

publicstaticexternintShowWindow(

inthwnd,

intnCmdShow

);

privatevoidbutton1_Click(objectsender,EventArgse)

{

//最小化

ShowWindowAsync(this.Handle, SW_MINIMIZE);

}

privatevoidbutton2_Click(objectsender,EventArgse)

{

//最大化

ShowWindowAsync(this.Handle, SW_MAXIMIZE);

}

privatevoidbutton3_Click(objectsender,EventArgse)

{

//還原

ShowWindowAsync(this.Handle, SW_RESTORE);

}

privatevoidbutton4_Click(objectsender,EventArgse)

{

//最小化

ShowWindow((int)this.Handle, SW_MINIMIZE);

}

privatevoidbutton5_Click(objectsender,EventArgse)

{

//最大化

ShowWindow((int)this.Handle, SW_MAXIMIZE);

}

privatevoidbutton6_Click(objectsender,EventArgse)

{

//還原

ShowWindow((int)this.Handle, SW_RESTORE);

}

}

}

轉載自：http://www.dotblogs.com.tw/yc421206/archive/2009/07/06/9140.aspx