如何在 Winforms 应用程序的配置中保存对象？

Question

我正在尝试实现允许用户选择他最喜欢的表单的功能。最喜欢的表格是他/她需要快速访问的表格。为了避免浏览 ToolStripMenu 的时间过长。

我尝试在应用程序配置中保存对表单的引用。但我得到了错误

“System.Windows.Forms.Form”类型的值无法转换为 '字符串'。

Public Sub SetSetting(ByVal pstrKey As String, ByVal frmFavorite As Form)
    Dim keyExists As Boolean = False
    For Each strKey As String In configuration.AppSettings.Settings.AllKeys
        If strKey.Equals(pstrKey) Then
            configuration.AppSettings.Settings.Item(pstrKey).Value = frmFavorite
            keyExists = True
        End If
    Next

    If Not keyExists Then
        configuration.AppSettings.Settings.Add(pstrKey, frmFavorite)
    End If
    configuration.Save(ConfigurationSaveMode.Modified)
    ConfigurationManager.RefreshSection("appSettings")
End Sub

Answer 1

您只能在应用程序配置文件中存储 string 值，不能存储对象。
但只需将表单的名称存储在配置文件中。 启动应用程序时，通过反射创建表单，如 this Object Factory 示例所示。

Public Class ObjectFactory

  Public Shared Function CreateAnObject(ByVal ObjectName As String) As Object
        Dim Assem = [Assembly].GetExecutingAssembly()

        Dim myType As Type = Assem.GetType(ObjectName.Trim)
        Dim o As Object = Nothing
        Try
            o = Activator.CreateInstance(myType)
        Catch oEx As TargetInvocationException
            MessageBox.Show(oEx.ToString)
        End Try

        Return o
    End Function
End Class

...

Dim formName as String = configuration.AppSettings.Settings.Item(<YourSettingKey>)

Dim oForm As Form = _
        ObjectFactory.CreateAnObject(formName)