如何在 Windows操作系統(tǒng)中改變文件打開方式

一、基本思路：

　　１、注冊表編輯器Regedit.exe是用于更改系統(tǒng)注冊表設(shè)置的高級工具，包含了關(guān)于系統(tǒng)配置及運行的重要信息，默認訪問路徑為C:\Windows\Regedit.exe，。雙擊Regedit.exe圖標，運行注冊表編輯器。在左側(cè)顯示欄內(nèi)看到HKEY_CLASSES_ROOT、HKEY_CURRENT_USER、HKEY_LOCAL_MACHINE等主鍵。與文件類型有關(guān)的所有主鍵、鍵名、鍵值都存放在HKEY_CLASSES_ROOT下。

　　改變打開文件方式的方法（例如用VISIO打開*.exc文件）：

　　◆編程：利用VB、Delphi、C++Builder等讀寫系統(tǒng)注冊表，可自動改變文件打開方式。本文提供VB、Delphi編程實例。

　　二、編程實例：

　　１、在VB5.0 IDE中，新建工程Project1，在Form1上添加命令按鈕Command1。

　２、選擇菜單“工程”棥疤砑幽？欏睏“模塊”棥按蚩?保?赑roject1中添加模塊Moudle1。

　　３、在Moudle１“通用椛?鰲輩糠稚?鰽PI函數(shù)和常量。

Const REG_SZ = 1

Global Const HKEY_CLASSES_ROOT = &H80000000

Declare Function OSRegQueryValueEx Lib "advapi32" Alias "RegQueryValueExA" (ByVal hKey As Long, ByVal lpszValueName As String, ByVal dwReserved As Long, lpdwType As Long, lpbData As Any, cbData As Long) As Long

Declare Function OSRegOpenKey Lib "advapi32" Alias "RegOpenKeyA" (ByVal hKey As Long, ByVal lpszSubKey As String, phkResult As Long) As Long

Declare Function OSRegSetValueEx Lib "advapi32" Alias "RegSetValueExA" (ByVal hKey As Long, ByVal lpszValueName As String, ByVal dwReserved As Long, ByVal fdwType As Long, lpbData As Any, ByVal cbData As Long) As Long

Declare Function OSRegCloseKey Lib "advapi32" Alias "RegCloseKey" (ByVal hKey As Long) As Long

　　４、在Moudle 1中編寫函數(shù)。

Function RegOpenKey(ByVal hKey As Long, ByVal lpszSubKey As String, phkResult As Long) As Boolean

Dim lResult As Long

On Error GoTo 0 ' 關(guān)閉錯誤陷阱

lResult = OSRegOpenKey(hKey, lpszSubKey, phkResult)

If lResult = 0 Then

RegOpenKey = True

Else

RegOpenKey = False

End If

End Function

Function RegSetStringValue(ByVal hKey As Long, ByVal strValueName As String, ByVal strData As String, Optional ByVal fLog) As Boolean

Dim lResult As Long

On Error GoTo 0

lResult = OSRegSetValueEx(hKey, strValueName, 0&, REG_SZ, ByVal strData, LenB(StrConv(strData, vbFromUnicode)) + 1)

If lResult = 0 Then

RegSetStringValue = True

Else

RegSetStringValue = False

End If

End Function

Function StripTerminator(ByVal strString As String) As String

Dim intZeroPos As Integer

intZeroPos = InStr(strString, Chr$(0))

If intZeroPos > 0 Then

StripTerminator = Left$(strString, intZeroPos - 1)

Else

StripTerminator = strString

End If

End Function

Function RegQueryStringValue(ByVal hKey As Long, ByVal strValueName As String, strData As String) As Boolean

Dim lResult As Long

Dim lValueType As Long

Dim strBuf As String

Dim lDataBufSize As Long

RegQueryStringValue = False

On Error GoTo 0

lResult = OSRegQueryValueEx(hKey, strValueName, 0&, lValueType, ByVal 0&, lDataBufSize)

If lResult = ERROR_SUCCESS Then

If lValueType = REG_SZ Then

strBuf = String(lDataBufSize, " ")

lResult = OSRegQueryValueEx(hKey, strValueName, 0&, 0&, ByVal strBuf, lDataBufSize)

If lResult = ERROR_SUCCESS Then

RegQueryStringValue = True

strData = StripTerminator(strBuf)

End If

End If

End If

End Function

　　５、雙擊Command1，編寫Click事件代碼。

Private Sub Command1_Click()

Dim hKey As Long

Dim MyReturn As Long

Dim MyData As String

MyReturn = OSRegOpenKey(HKEY_CLASSES_ROOT, ".exc", hKey)

MyReturn = RegQueryStringValue(hKey, "", MyData)

MyReturn = OSRegOpenKey(HKEY_CLASSES_ROOT, MyData + "\shell\open\command", hKey)

MyReturn = RegSetStringValue(hKey, "", "c:\visio.exe 1%", False)

If MyReturn Then

MsgBox "改變文件打開方式成功！", vbInformation, "請注意"

Else

MsgBox "改變文件打開方式失敗！", vbExclamation, "請注意"

End If

OSRegCloseKey (hKey)

End Sub

　　６、按F5運行程序，在簡體中文Windows95／NT／98、VB5.0／6.0環(huán)境中調(diào)試通過。

　　１、在Delphi3.0 IDE中，新建工程Project1，在Form1上添加按鈕Button1。

　２、在uses子句中添加Registry。

　　３、雙擊Button1，編寫Click事件代碼。

procedure TForm1.Button1Click(Sender: TObject);

var

MyRegistry : TRegINIFile;

Return:string;

begin

try

MyRegistry := TRegINIFile.Create('');

MyRegistry.RootKey := HKEY_CLASSES_ROOT;

Return:=MyRegistry.ReadString ('.gid','','No! Not Found the Key!');

MyRegistry.WriteString(Return,'','這只是一個演示！');

MyRegistry.WriteString(Return+'\DefaultIcon','','c:\visio.exe,1');

MyRegistry.WriteString(Return+'\shell\open\command','','c:\visio.exe %1');

finally

MyRegistry.Free;

end;

ShowMessage('改變文件打開方式成功！');

end;

　　４、按F9運行程序，在簡體中文Windows95／NT／98、Delphi3.0／4.0環(huán)境中調(diào)試通過。

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