使用WinAPI的FindWindow判斷程式是否運行
一、問題說明
如何透過 WinAPI中的 FindWindow 來判斷 該程式 是否在運行
二、方法
Windows API 中的 FindWindws : 尋找指定視窗類別、名稱之視窗代號 (hWnd) ，使用方式相當簡單，先調用此函數
Declare Function FindWindow Lib "user32" Alias "FindWindowA" (ByVal lpClassName As String, ByVal lpWindowName As String) As Integer
Declare Function接著透過以下程式碼，修改 "程式名稱" 即可
Dim hwd1 As IntPtr hwd1 = FindWindow(vbNullString, "程式名稱") If hwd1.Equals(IntPtr.Zero) Then Label1.Text = "該程式未運行" Else Label1.Text = "該程式已運行" End If
三、範例
以下程式碼的功能為程式執行時會開啟 Form1 與 Form2 ， Form2 在三秒後關閉，而 Form2 的執行與否將會顯示在 Form1 的 Label1 中
Form1 程式碼
01 
Public Class Form1
02
03 Declare Function FindWindow Lib "user32" Alias "FindWindowA" (ByVal lpClassName As String, ByVal lpWindowName As String) As Integer
04
05
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
06 Dim f2 As New Form2
07 f2.TopMost = False
08 f2.Show()
09
10 Timer1.Interval = 100
11 Timer1.Enabled = True
12
End Sub
13
14 Private Sub Timer1_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Timer1.Tick
15 Dim hwd1 As IntPtr
16 hwd1 = FindWindow(vbNullString, "Form2")
17
18 If hwd1.Equals(IntPtr.Zero) Then
19 Label1.Text = "該程式未運行"
20 Else
21 Label1.Text = "該程式已運行"
22 End If
23
24
End Sub
25End Class
Public Class Form1 02
03
Declare Function FindWindow Lib "user32" Alias "FindWindowA" (ByVal lpClassName As String, ByVal lpWindowName As String) As Integer 04
05
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load 
Private06
Dim f2 As New Form2 07
f2.TopMost = False 08
f2.Show() 09
10
Timer1.Interval = 100 11
Timer1.Enabled = True 12
End Sub 13
14
Private Sub Timer1_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Timer1.Tick 15
Dim hwd1 As IntPtr 16
hwd1 = FindWindow(vbNullString, "Form2") 17
18
If hwd1.Equals(IntPtr.Zero) Then 19
Label1.Text = "該程式未運行" 20
Else 21
Label1.Text = "該程式已運行" 22
End If 23
24
End Sub 25
End Class
Form2
01 Public Class Form2
02 Private Sub Form2_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
03 Timer1.Interval = 3000
04 Timer1.Enabled = True
05 End Sub
06
07 Private Sub Timer1_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Timer1.Tick
08 Me.Close()
09 End Sub
10End Class
Public Class Form2 02
Private Sub Form2_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load 03
Timer1.Interval = 3000 04
Timer1.Enabled = True 05
End Sub 06
07
Private Sub Timer1_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Timer1.Tick 08
Me.Close() 09
End Sub 10
End Class
四、執行結果
五、參考
發問問題網址
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