如何使用箭头键在文本框之间移动光标? [英] How to move the cursor between textboxes using arrow keys?

问题描述

我有几个 TextBoxes ，我希望使用箭头键将光标从一个 TextBox 移到另一个.

I have several TextBoxes and I want the cursor to move from one TextBox to another using arrow keys.

我该怎么做?

看起来像这样，水龙头也垂直移动，这很奇怪.

It looks like this, also the tap moves vertically which is weird.

谢谢.

推荐答案

您可以覆盖窗体的 ProcessCmdKey 方法，并处理按键并集中注意其中的文本框.

You can override the form's ProcessCmdKey method, and handle the key press and focusing on text boxes in it.

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;

namespace TextBoxes
{
    public partial class Form1 : Form
    {
        List<TextBox[]> _textBoxes;
        public Form1()
        {
            InitializeComponent();

            //Getting a 2 dimentional structure to hold textboxes
            this._textBoxes= new List<TextBox[]>();

            TextBox[] row1 = new TextBox[4];
            row1[0] = textBox1;
            row1[1] = textBox2;
            row1[2] = textBox3;
            row1[3] = textBox4;

            TextBox[] row2 = new TextBox[4];
            row2[0] = textBox5;
            row2[1] = textBox6;
            row2[2] = textBox7;
            row2[3] = textBox8;

            TextBox[] row3 = new TextBox[4];
            row3[0] = textBox9;
            row3[1] = textBox10;
            row3[2] = textBox11;
            row3[3] = textBox12;

            TextBox[] row4 = new TextBox[4];
            row4[0] = textBox13;
            row4[1] = textBox14;
            row4[2] = textBox15;
            row4[3] = textBox16;

            this._textBoxes.Add(row1);
            this._textBoxes.Add(row2);
            this._textBoxes.Add(row3);
            this._textBoxes.Add(row4); 
        }

         /// <summary>
         /// Processes a command key.
         /// </summary>
         /// <param name="msg">A <see cref="T:System.Windows.Forms.Message"/>, passed by reference, that represents the Win32 message to process.</param>
         /// <param name="keyData">One of the <see cref="T:System.Windows.Forms.Keys"/> values that represents the key to process.</param>
         /// <returns>
         /// true if the keystroke was processed and consumed by the control; otherwise, false to allow further processing.
         /// </returns>
        protected override bool ProcessCmdKey(ref Message msg, Keys keyData)
        {
            //A key was pressed! 
            Control activeCtrl = this.ActiveControl;
            TextBox txb = activeCtrl as TextBox;
            //Handle it only if it was sent when a textbox was focused
            if (txb != null)
            {
                int row;
                int column;
                //find out which text box is currently active
                this.GetTextBoxIndexes(txb, out row, out column);

                //change indexes according to key stroke
                if (keyData == Keys.Up)
                {
                    row--;
                }
                else if (keyData == Keys.Down)
                {
                    row++;
                }
                else if (keyData == Keys.Left)
                {
                    column--;
                }
                else if (keyData == Keys.Right)
                {
                    column++;
                }
                //Make sure we are not in negative / out of ranfe index
                row = Math.Abs(row + 4) % 4;
                column = Math.Abs(column + 4) % 4;

                //focus requested text box
                TextBox slected = this._textBoxes[row][column];
                slected.Focus();

            }
            //don't forget not to break the chain...
            return base.ProcessCmdKey(ref msg, keyData);
        }

        /// <summary>
        /// Gets the text box indexes.
        /// </summary>
        /// <param name="txb">The texbox.</param>
        /// <param name="row">The out row index.</param>
        /// <param name="column">The out column index.</param>
        private void GetTextBoxIndexes(TextBox txb, out int row, out int column)
        {
            row = -1;
            column = -1;
            for (int rowIdx = 0; rowIdx < this._textBoxes.Count; rowIdx++)
            {
                TextBox[] currRow = this._textBoxes[rowIdx];
                for (int colIdx = 0; colIdx < currRow.Length; colIdx++)
                {
                    TextBox currTextBox = this._textBoxes[rowIdx][colIdx];
                    if (currTextBox.Equals(txb))
                    {
                        row = rowIdx;
                        column = colIdx;
                        return;
                    }
                }
            }
        }
    }
}

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