vb.net 保存文本框值以备后用

您可以在类型为 StringCollection 的应用程序设置条目中存储和检索搜索词列表作为 TextBox.AutoCompleteCustomsource 属性的数据源。

添加新条目

• 从项目菜单中选择YourAppName属性。
• 选择设置标签。
• 在名称列中添加新条目，例如：SearchWords。
• 从类型列中，选择System.Collections.Specialized.StringCollection。
• 关闭对话框并保存。

检索搜索词

在表单的构造函数或 Load 事件中，假设您有一个名为 TextBox 的搜索 txtSearch：

' +
Imports System.Linq
Imports System.Collections.Specialized

Private Sub YourForm_Load(sender As Object,e As EventArgs) Handles MyBase.Load
    If My.SetTings.SearchWords Is Nothing Then
        My.SetTings.SearchWords = new StringCollection
    End If

    Dim acc As New AutoCompleteStringCollection
    acc.AddRange(My.SetTings.SearchWords.Cast(Of String).ToArray())

    txtSearch.AutoCompleteMode = AutoCompleteMode.Suggest
    txtSearch.AutoCompletesource = AutoCompletesource.Customsource
    txtSearch.AutoCompleteCustomsource = acc
End Sub

更新集合

每次执行搜索时都需要添加新词：

' When you click a search button...
Private Sub btnSearch_Click(sender As Object,e As EventArgs) Handles btnSearch.Click
    AddSearchWord()
End Sub

' If you call the search routIne when you press the Enter key...
Private Sub txtSearch_KeyDown(sender As Object,e As KeyEventArgs) Handles txtSearch.KeyDown
    If e.KeyCode = Keys.Enter Then
        AddSearchWord()
    End If
End Sub

' update the collection...
Private Sub AddSearchWord()
    If txtSearch.Text.Trim.Length = 0 Then Return

    If Not txtSearch.AutoCompleteCustomsource.Contains(txtSearch.Text) Then

        If txtSearch.AutoCompleteCustomsource.Count > 10 Then
            txtSearch.AutoCompleteCustomsource.RemoveAt(
                txtSearch.AutoCompleteCustomsource.Count - 1)
        End If

        txtSearch.AutoCompleteCustomsource.Insert(0,txtSearch.Text)
    End If
End Sub

保存收藏

关闭表单时更新 SearchWord 字符串集合：

Private Sub YourForm_FormClosing(sender As Object,e As FormClosingEventArgs) Handles MyBase.FormClosing
    My.SetTings.SearchWords = new StringCollection
    My.SetTings.SearchWords.AddRange(txtSearch.AutoCompleteCustomsource.Cast(Of String).ToArray)
    My.SetTings.Save()
End Sub

演示

我发现了一些代码 Saving text box values to a file to load again，我根据自己的需要进行了更改。当我单击提交按钮时，它将 ComboBox1 的内容保存到文本文件中。当我加载表单时，文本文件被读取并加载到 ComboBox1 中作为以前使用的搜索。

   'now save the search word to our textfile
    PresetName = TextBoxFreeText.Text
    If PresetName <> "" Then
        TextBoxFreeText.Items.Add(PresetName)
        Call SaveData(PresetName)
    End If

加载保存值的代码：

Private Sub ReadData()
        If My.Computer.FileSystem.FileExists(FilePath) = True Then
            myReader = New StreamReader(FilePath)
            Dim myText = myReader.ReadLine
            While myText Isnot Nothing
                listPreset.Add(myText)
                myText = myReader.ReadLine
            End While
            myReader.Close()
            'Add Preset Names to ComboBox
            If listPreset.Count > 0 Then
                Dim PresetName As String
                Dim index As Integer
                For i = 0 To listPreset.Count - 1
                    index = listPreset.Item(i).IndexOf(",")
                    PresetName = Mid(listPreset.Item(i),1,indeX)
                    TextBoxFreeText.Items.Add(PresetName)
                Next
            End If
        End If
    End Sub

保存ComboBox1内容的代码

Private Sub SaveData(ByVal PresetName As String)
        Dim FileString As String = PresetName & ","
        'Build File String

        FileString &= TextBoxFreeText.Text & ","
        listPreset.Add(FileString)
        myWriter = New StreamWriter(FilePath)
        For i = 0 To listPreset.Count - 1
            myWriter.WriteLine(listPreset.Item(i))
        Next
        myWriter.Close()

    End Sub

还有两件事我想改变。我会问一个新问题。

1. 防止在文本文件中输入重复的搜索字符串。
2. 为 ComboBox1 中加载的搜索字符串设置最大值（可能是 10 个字）