请教数据库连接问题

[zhupeibin]

我如何做，如我有个窗体用来输入服务器，数据库名和登陆数据库的用户名，密码，如何让系统记住这些参数，不必以后再启动系统，每次都要输入。谢谢
希望给出代码

[lihonggen0]

你可以将输入的这几个变量存入注册表或ini文件，
下一次程序启动的时候从注册表或ini文件读出来

[daviddivad]

把这些值保存在注册表，或者写在一个文件中，如配置文件（*.ini）

[lihonggen0]

建立与读取.ini文件


'请於form中放3个TextBox，一个CommandBox
Private Declare Function GetPrivateProfileString Lib "kernel32" _
Alias "GetPrivateProfileStringA" (ByVal lpApplicationName As String, _
ByVal lpKeyName As Any, ByVal lpDefault As String, _
ByVal lpReturnedString As String, ByVal nSize As Long, _
ByVal lpFileName As String) As Long
Private Declare Function WritePrivateProfileString Lib "kernel32" _
Alias "WritePrivateProfileStringA" (ByVal lpApplicationName As String, _
ByVal lpKeyName As Any, ByVal lpString As Any, _
ByVal lpFileName As String) As Long

Private Sub Command1_Click()
Dim success As Long
success = WritePrivateProfileString("MyApp", "text1", Text1.Text, "c:\aa.ini")
'叁数一 Section Name
'叁数二 於.ini中的项目
'叁数三 项目的内容
'叁数四 .ini文件的名称
success = WritePrivateProfileString("MyApp", "text2", Text2.Text, "c:\aa.ini")
success = WritePrivateProfileString("MyApp2", "text3", Text3.Text, "c:\aa.ini")
End Sub

Private Sub Form_load()
Dim ret As Long
Dim buff As String
buff = String(255, 0)
ret = GetPrivateProfileString("Myapp", "text1", "text1", buff, 256, "c:\aa.ini")
'若.ini MyApp中无text1，则采用叁数三的值
Text1.Text = buff
buff = String(255, 0)
ret = GetPrivateProfileString("Myapp", "text2", "text2", buff, 256, "c:\aa.ini")
Text2.Text = buff
buff = String(255, 0)
ret = GetPrivateProfileString("Myapp2", "text3", "text3", buff, 256, "c:\aa.ini")
Text3.Text = buff
End Sub

[lihonggen0]

注册表读写实例：

'This program needs 3 buttons
Const REG_SZ = 1 ' Unicode nul terminated string
Const REG_BINARY = 3 ' Free form binary
Const HKEY_CURRENT_USER = &H80000001
Private Declare Function RegCloseKey Lib "advapi32.dll" (ByVal hKey As Long) As Long
Private Declare Function RegCreateKey Lib "advapi32.dll" Alias "RegCreateKeyA" (ByVal hKey As Long, ByVal lpSubKey As String, phkResult As Long) As Long
Private Declare Function RegDeleteValue Lib "advapi32.dll" Alias "RegDeleteValueA" (ByVal hKey As Long, ByVal lpValueName As String) As Long
Private Declare Function RegOpenKey Lib "advapi32.dll" Alias "RegOpenKeyA" (ByVal hKey As Long, ByVal lpSubKey As String, phkResult As Long) As Long
Private Declare Function RegQueryValueEx Lib "advapi32.dll" Alias "RegQueryValueExA" (ByVal hKey As Long, ByVal lpValueName As String, ByVal lpReserved As Long, lpType As Long, lpData As Any, lpcbData As Long) As Long
Private Declare Function RegSetValueEx Lib "advapi32.dll" Alias "RegSetValueExA" (ByVal hKey As Long, ByVal lpValueName As String, ByVal Reserved As Long, ByVal dwType As Long, lpData As Any, ByVal cbData As Long) As Long
Function RegQueryStringValue(ByVal hKey As Long, ByVal strValueName As String) As String
Dim lResult As Long, lValueType As Long, strBuf As String, lDataBufSize As Long
'retrieve nformation about the key
lResult = RegQueryValueEx(hKey, strValueName, 0, lValueType, ByVal 0, lDataBufSize)
If lResult = 0 Then
If lValueType = REG_SZ Then
'Create a buffer
strBuf = String(lDataBufSize, Chr$(0))
'retrieve the key's content
lResult = RegQueryValueEx(hKey, strValueName, 0, 0, ByVal strBuf, lDataBufSize)
If lResult = 0 Then
'Remove the unnecessary chr$(0)'s
RegQueryStringValue = Left$(strBuf, InStr(1, strBuf, Chr$(0)) - 1)
End If
ElseIf lValueType = REG_BINARY Then
Dim strData As Integer
'retrieve the key's value
lResult = RegQueryValueEx(hKey, strValueName, 0, 0, strData, lDataBufSize)
If lResult = 0 Then
RegQueryStringValue = strData
End If
End If
End If
End Function
Function GetString(hKey As Long, strPath As String, strValue As String)
Dim Ret
'Open the key
RegOpenKey hKey, strPath, Ret
'Get the key's content
GetString = RegQueryStringValue(Ret, strValue)
'Close the key
RegCloseKey Ret
End Function
Sub SaveString(hKey As Long, strPath As String, strValue As String, strData As String)
Dim Ret
'Create a new key
RegCreateKey hKey, strPath, Ret
'Save a string to the key
RegSetValueEx Ret, strValue, 0, REG_SZ, ByVal strData, Len(strData)
'close the key
RegCloseKey Ret
End Sub
Sub SaveStringLong(hKey As Long, strPath As String, strValue As String, strData As String)
Dim Ret
'Create a new key
RegCreateKey hKey, strPath, Ret
'Set the key's value
RegSetValueEx Ret, strValue, 0, REG_BINARY, CByte(strData), 4
'close the key
RegCloseKey Ret
End Sub
Sub DelSetting(hKey As Long, strPath As String, strValue As String)
Dim Ret
'Create a new key
RegCreateKey hKey, strPath, Ret
'Delete the key's value
RegDeleteValue Ret, strValue
'close the key
RegCloseKey Ret
End Sub
Private Sub Command1_Click()
Dim strString As String
'Ask for a value
strString = InputBox("Please enter a value between 0 and 255 to be saved as a binary value in the registry.", App.Title)
If strString = "" Or Val(strString) > 255 Or Val(strString) < 0 Then
MsgBox "Invalid value entered ...", vbExclamation + vbOKOnly, App.Title
Exit Sub
End If
'Save the value to the registry
SaveStringLong HKEY_CURRENT_USER, "KPD-Team", "BinaryValue", CByte(strString)
End Sub
Private Sub Command2_Click()
'Get a string from the registry
Ret = GetString(HKEY_CURRENT_USER, "KPD-Team", "BinaryValue")
If Ret = "" Then MsgBox "No value found !", vbExclamation + vbOKOnly, App.Title: Exit Sub
MsgBox "The value is " + Ret, vbOKOnly + vbInformation, App.Title
End Sub
Private Sub Command3_Click()
'Delete the setting from the registry
DelSetting HKEY_CURRENT_USER, "KPD-Team", "BinaryValue"
MsgBox "The value was deleted ...", vbInformation + vbOKOnly, App.Title
End Sub
Private Sub Form_Load()

Command1.Caption = "Set Value"
Command2.Caption = "Get Value"
Command3.Caption = "Delete Value"
End Sub

[cloud1002]

up

[zhupeibin]

谢谢lihonggen0(李洪根,用.NET，标准答案来了)，你太厉害了，虽然我不懂你写的这段程序，但是INI已实验成功，还要加强学习。
又有问题拉，写进去后，如何在启动是读出来呢
不过觉得这样安全性不好

[snail2011]

那就让登陆用户使用密码了,
密码不要显示出来就行了,
让他自己输入密码.!