如何在Winforms桌面應用程序中制作自動完成的文本框

Question

我有一個詞表。 該列表包含大約100-200個文本字符串（實際上是地鐵站的名稱）。

我想制作一個自動完成的文本框。 例如，用戶按“ N”字母，然后出現一個（結束）適當的選項（僅一個選項）。 必須選擇結尾。

怎么做？

PS1：我猜想，有一個帶有屬性的文本框控件，如下所示：

List<string> AppropriateOptions{/* ... */}

PS2：對不起，我的英語。 如果您聽不懂->問我，我會盡力解釋！

Answer 1

以防萬一@leniel的鏈接斷開，下面的代碼可以解決問題：

AutoCompleteStringCollection allowedTypes = new AutoCompleteStringCollection();
allowedTypes.AddRange(yourArrayOfSuggestions);
txtType.AutoCompleteCustomSource = allowedTypes;
txtType.AutoCompleteMode = AutoCompleteMode.Suggest;
txtType.AutoCompleteSource = AutoCompleteSource.CustomSource;

Answer 2

使用組合框而不是文本框。 下面的示例將自動完成，匹配文本的任何部分，而不僅僅是起始字母。

這應該是一個完整的表格，只需添加您自己的數據源和數據源列名。 :-)

using System;
using System.Data;
using System.Windows.Forms;

public partial class frmTestAutocomplete : Form
{

    private DataTable maoCompleteList;
    private const string MC_DISPLAY_COL = "name";
    private const string MC_ID_COL = "id";

    public frmTestAutocomplete()
    {
        InitializeComponent();
    }

    private void frmTestAutocomplete_Load(object sender, EventArgs e)
    {

        maoCompleteList = oData.PurificationRuns;
        maoCompleteList.CaseSensitive = false; //turn off case sensitivity for searching

        testCombo.DisplayMember = MC_DISPLAY_COL;
        testCombo.ValueMember = MC_ID_COL;
        testCombo.DataSource = GetDataTableFromDatabase();
        testCombo.SelectedIndexChanged += testCombo_SelectedIndexChanged;
        testCombo.KeyUp += testCombo_KeyUp;
    }


    private void testCombo_KeyUp(object sender, KeyEventArgs e)
    {
        //use keyUp event, as text changed traps too many other evengts.

        ComboBox oBox = (ComboBox)sender;
        string sBoxText = oBox.Text;

        DataRow[] oFilteredRows = maoCompleteList.Select(MC_DISPLAY_COL + " Like '%" + sBoxText + "%'");

        DataTable oFilteredDT = oFilteredRows.Length > 0
                                ? oFilteredRows.CopyToDataTable()
                                : maoCompleteList;

        //NOW THAT WE HAVE OUR FILTERED LIST, WE NEED TO RE-BIND IT WIHOUT CHANGING THE TEXT IN THE ComboBox.

        //1).UNREGISTER THE SELECTED EVENT BEFORE RE-BINDING, b/c IT TRIGGERS ON BIND.
        testCombo.SelectedIndexChanged -= testCombo_SelectedIndexChanged; //don't select on typing.
        oBox.DataSource = oFilteredDT; //2).rebind to filtered list.
        testCombo.SelectedIndexChanged += testCombo_SelectedIndexChanged;


        //3).show the user the new filtered list.
        oBox.DroppedDown = true; //this will overwrite the text in the ComboBox, so 4&5 put it back.

        //4).binding data source erases text, so now we need to put the user's text back,
        oBox.Text = sBoxText;
        oBox.SelectionStart = sBoxText.Length; //5). need to put the user's cursor back where it was.


    }

    private void testCombo_SelectedIndexChanged(object sender, EventArgs e)
    {

        ComboBox oBox = (ComboBox)sender;

        if (oBox.SelectedValue != null)
        {
            MessageBox.Show(string.Format(@"Item #{0} was selected.", oBox.SelectedValue));
        }
    }

}

//=====================================================================================================
//      code from frmTestAutocomplete.Designer.cs
//=====================================================================================================
partial class frmTestAutocomplete

{
    /// <summary>
    /// Required designer variable.
    /// </summary>
    private readonly System.ComponentModel.IContainer components = null;

    /// <summary>
    /// Clean up any resources being used.
    /// </summary>
    /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
    protected override void Dispose(bool disposing)
    {
        if (disposing && (components != null))
        {
            components.Dispose();
        }
        base.Dispose(disposing);
    }

    #region Windows Form Designer generated code

    /// <summary>
    /// Required method for Designer support - do not modify
    /// the contents of this method with the code editor.
    /// </summary>
    private void InitializeComponent()
    {
        this.testCombo = new System.Windows.Forms.ComboBox();
        this.SuspendLayout();
        // 
        // testCombo
        // 
        this.testCombo.FormattingEnabled = true;
        this.testCombo.Location = new System.Drawing.Point(27, 51);
        this.testCombo.Name = "testCombo";
        this.testCombo.Size = new System.Drawing.Size(224, 21);
        this.testCombo.TabIndex = 0;
        // 
        // frmTestAutocomplete
        // 
        this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
        this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
        this.ClientSize = new System.Drawing.Size(292, 273);
        this.Controls.Add(this.testCombo);
        this.Name = "frmTestAutocomplete";
        this.Text = "frmTestAutocomplete";
        this.Load += new System.EventHandler(this.frmTestAutocomplete_Load);
        this.ResumeLayout(false);

    }

    #endregion

    private System.Windows.Forms.ComboBox testCombo;
}

Answer 3

Leniel的答案鏈接位於vb.net，感謝Joel的輸入。 提供我的代碼使其更明確：

private void InitializeTextBox()
{

    AutoCompleteStringCollection allowedStatorTypes = new AutoCompleteStringCollection();
    var allstatortypes = StatorTypeDAL.LoadList<List<StatorType>>().OrderBy(x => x.Name).Select(x => x.Name).Distinct().ToList();

    if (allstatortypes != null && allstatortypes.Count > 0)
    {
        foreach (string item in allstatortypes)
        {
            allowedStatorTypes.Add(item);
        }
    }

    txtStatorTypes.AutoCompleteMode = AutoCompleteMode.Suggest;
    txtStatorTypes.AutoCompleteSource = AutoCompleteSource.CustomSource;
    txtStatorTypes.AutoCompleteCustomSource = allowedStatorTypes;
}

Answer 4

我想補充一下，TextBox的標准自動完成功能僅從字符串的開頭開始起作用，因此，如果您按N，則只會找到以N開頭的字符串。 如果您想要更好的東西，則必須使用一些不同的控件或自己實現行為（即，使用一些計時器對TextChanged Event做出反應以延遲執行），而不是使用IndexOf（inputString）過濾令牌列表搜索，然后將AutoCompleteSource設置為過濾后的列表。

Answer 5

您想要將TextBox.AutoCompleteSource設置為CustomSource ，然后將所有字符串添加到其AutoCompleteCustomSource屬性（即StringCollection 。 那你應該很好。

Answer 6

使用組合框，設置其數據源或提供硬編碼的條目，但設置以下屬性：

    AutoCompleteMode = Suggest;
    AutoCompleteSource = ListItems;

Answer 7

找到此鏈接，對https://docs.microsoft.com/zh-cn/dotnet/api/system.windows.forms.textbox.autocompletemode?view=netframework-4.8會有所幫助