在C#中获取文本框中光标所在位置

最新推荐文章于 2021-01-24 18:44:39 发布

Snowdust

最新推荐文章于 2021-01-24 18:44:39 发布

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分类专栏： DotNET 文章标签： c# button user object system string

本文链接：https://blog.youkuaiyun.com/snowdust/article/details/1431284

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本文介绍了如何在C#中获取文本框中的光标位置，通过定义API函数并实现特定的获取位置函数，提供了完整的代码示例。

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首先定义API函数

const int EM_GETSEL = 0xB0;
const int EM_LINEFROMCHAR = 0xC9;
const int EM_LINEINDEX = 0xBB;
[DllImport("user32.dll", EntryPoint = "SendMessage")]
public static extern int SendMessage(
    int hwnd,
    int wMsg,
    int wParam,
    ref int lParam
);

获取位置的函数

private Point GetCursorPos(int TextHwnd)
{
    int i = 0, j = 0, k = 0;
    int lParam = 0, wParam = 0;
    i = SendMessage(TextHwnd, EM_GETSEL, wParam, ref lParam);
    j = i / 65536;
    int lineNo = SendMessage(TextHwnd, EM_LINEFROMCHAR, j, ref lParam) + 1;
    k = SendMessage(TextHwnd, EM_LINEINDEX, -1, ref lParam);
    int colNo = j - k + 1;
    Point ret = new Point(lineNo, colNo);
    return ret;
}

完整代码如下：

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

namespace CSWin
{
    public partial class Form1 : Form
    {
        const int EM_GETSEL = 0xB0;
        const int EM_LINEFROMCHAR = 0xC9;
        const int EM_LINEINDEX = 0xBB;
        [DllImport("user32.dll", EntryPoint = "SendMessage")]
        public static extern int SendMessage(
            int hwnd,
            int wMsg,
            int wParam,
            ref int lParam
        );
        private Point GetCursorPos(int TextHwnd)
        {
            int i = 0, j = 0, k = 0;
            int lParam = 0, wParam = 0;
            i = SendMessage(TextHwnd, EM_GETSEL, wParam, ref lParam);
            j = i / 65536;
            int lineNo = SendMessage(TextHwnd, EM_LINEFROMCHAR, j, ref lParam) + 1;
            k = SendMessage(TextHwnd, EM_LINEINDEX, -1, ref lParam);
            int colNo = j - k + 1;
            Point ret = new Point(lineNo, colNo);
            return ret;
        }
        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            Point p = GetCaretPos(this.textBox1.Handle.ToInt32());
            this.label1.Text = string.Format("Line:{0}, Col:{1}", p.X, p.Y);
        }
    }
}