Public Module Globals
Friend g_recipeData As RecipeEntities
End Module
在解决方案资源管理器中右键单击项目名称，选择属性。点击设置选项卡并添加以下新设置：
名称：lastpath
类型：字符串
范围：用户
值：
我的闪屏窗体如下所示：
窗体上的控件如下：
txtFile
cmdSelectDatabase
cmdNew
cmdOpen
cmdExit
Private Sub OnFormLoad() Handles Me.Load
txtFile.Text = My.Settings.lastpath
If txtFile.Text <> "" Then
cmdOpen.Enabled = True
cmdOpen.Select()
Else
cmdNew.Select()
End If
End Sub
Private Sub FileSelect()
Try
Dim openFileDialog As New OpenFileDialog()
openFileDialog.Filter = "sdf files (*.sdf)|*.sdf|All files (*.*)|*.*"
openFileDialog.FilterIndex = 1
openFileDialog.RestoreDirectory = True
Dim result As DialogResult = openFileDialog.ShowDialog(Me)
If result = DialogResult.Cancel Then
cmdSelectDatabase.Select()
Exit Sub
End If
txtFile.Text = openFileDialog.FileName
If txtFile.Text <> "" Then
cmdOpen.Enabled = True
cmdOpen.Select()
My.Settings.lastpath = openFileDialog.FileName
My.Settings.Save()
Else
cmdOpen.Enabled = False
cmdSelectDatabase.Select()
End If
Catch ex As Exception
MessageBox.Show(ex.Message.ToString, "Application Error")
Application.Exit()
Finally
End Try
End Sub
Private Sub SetConnectionString()
Try
Dim providerName As String = "System.Data.SqlServerCe.4.0"
Dim datasource As String = txtFile.Text
Dim sqlCeBuilder As New SqlCeConnectionStringBuilder
sqlCeBuilder.DataSource = datasource
sqlCeBuilder.PersistSecurityInfo = True
g_SQLCeConnectionString = sqlCeBuilder.ConnectionString
Dim providerString As String = sqlCeBuilder.ToString()
Dim entityBuilder As New EntityConnectionStringBuilder()
entityBuilder.Provider = providerName
entityBuilder.ProviderConnectionString = providerString
entityBuilder.Metadata = "res://*/RecipeModel.csdl|res://*/RecipeModel.ssdl|res://*/RecipeModel.msl"
Dim c As System.Configuration.Configuration = ConfigurationManager.OpenExeConfiguration(System.Reflection.Assembly.GetExecutingAssembly().Location)
Dim section As ConnectionStringsSection = DirectCast(c.GetSection("connectionStrings"), ConnectionStringsSection)
g_EntityConnectionString = entityBuilder.ConnectionString
section.ConnectionStrings("RecipeEntities").ConnectionString = g_EntityConnectionString
c.Save(ConfigurationSaveMode.Modified)
ConfigurationManager.RefreshSection("connectionStrings")
Catch ex As Exception
MessageBox.Show(ex.Message.ToString, "Application Error")
Application.Exit()
End Try
End Sub
Private Sub CreateDatabase()
Try
Dim saveFileDialog As New SaveFileDialog()
saveFileDialog.Filter = "sdf files (*.sdf)|*.sdf"
saveFileDialog.Title = "Create Database"
saveFileDialog.FilterIndex = 1
If saveFileDialog.ShowDialog() = DialogResult.OK Then
File.Copy(Path.Combine(ApplicationDeployment.CurrentDeployment.DataDirectory, "rw.sdf"), saveFileDialog.FileName, True)
Dim strPathandFile As String = saveFileDialog.FileName
txtFile.Text = strPathandFile
My.Settings.lastpath = strPathandFile
My.Settings.Save()
cmdOpen.Enabled = True
End If
Catch ex As Exception
MessageBox.Show(ex.Message.ToString, "Application Error")
Application.Exit()
End Try
End Sub
Private Sub LoadMainApplication()
Try
Dim objNewForm As New FrmMain
objNewForm.Show()
Me.Close()
Catch ex As Exception
MessageBox.Show(ex.Message.ToString, "Application Error")
Application.Exit()
End Try
End Sub
Private Sub cmdSelectDatabase_Click(sender As Object,
e As EventArgs) Handles cmdSelectDatabase.Click
FileSelect()
cmdOpen.Select()
End Sub
Private Sub cmdCancel_Click(sender As Object, e As EventArgs) Handles cmdExit.Click
Me.Close()
End Sub
Private Sub cmdOk_Click(sender As Object, e As EventArgs) Handles cmdOpen.Click
Me.Cursor = Cursors.WaitCursor
SetConnectionString()
LoadMainApplication()
Me.Cursor = Cursors.Default
End Sub
Private Sub txtFile_Validated(sender As Object, e As EventArgs) Handles txtFile.Validated
If txtFile.Text.Length = 0 Then
cmdOpen.Enabled = False
Else
cmdOpen.Enabled = True
End If
End Sub
Private Sub cmdNew_Click(sender As Object,
e As EventArgs) Handles cmdNew.Click
CreateDatabase()
SetConnectionString()
LoadMainApplication()
End Sub
Private Sub CatchEnterKey(ByVal sender As Object,
ByVal e As System.Windows.Forms.KeyPressEventArgs) _
Handles txtFile.KeyPress, txtPassword.KeyPress
If e.KeyChar = ChrW(Keys.Enter) Then
cmdOk_Click(sender, e)
e.Handled = True
Exit Sub
End If
End Sub
在您的主应用程序表单（如上所述的 frmMain）的构造函数中添加以下内容：
Public Sub New()
InitializeComponent()
g_recipeData = New RecipeEntities
End Sub