c#中WinForm的TextBox循环自动滚动示例

这个问题来自论坛提问，演示代码如下

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Text;

using System.Windows.Forms;

using System.Runtime.InteropServices;

namespace WindowsApplication27

{

/**//// <summary>

/// 演示如何在TextBox中让文字循环滚动:

/// </summary>

public partial class Form1 : Form

{

public Form1()

{

InitializeComponent();

this.textBox1.Clear();

for (int i = 0; i <= 20;i++ )

{

this.textBox1.Text += string.Format("{0}:jinjazz__{1} ", i,i);

}

this.timer1.Interval = 200;

this.timer1.Start();

}

//发送消息

[DllImport("user32.dll", EntryPoint = "SendMessage")]

public static extern int SendMessage(IntPtr hWnd, int wMsg, int wParam, int lParam);

//获取滚动条位置

[DllImport("user32")]

public static extern int GetScrollPos(IntPtr hwnd, int nBar);

//设置滚动条位置

[DllImport("user32.dll")]

static extern int SetScrollPos(IntPtr hWnd, int nBar,

int nPos, bool bRedraw);

public const int EM_LINESCROLL = 0xb6;

private void timer1_Tick(object sender, EventArgs e)

{

int i= GetScrollPos(this.textBox1.Handle,1);

//向下滚动一行

SendMessage(this.textBox1.Handle, EM_LINESCROLL, 0, 1);//0，1代表垂直滚动条向下滚动

//判断是否有位置变化，如果没有则说明到了底部，返回开始处

if (i == GetScrollPos(this.textBox1.Handle, 1))

{

//回到顶部，这里用SetScrollPos似乎有问题，滚动条和文字不是同步更新

this.textBox1.SelectionStart = 0;

this.textBox1.SelectionLength = 1;

this.textBox1.ScrollToCaret();

this.textBox1.SelectionLength = 0;

}

Console.WriteLine(i);

}

private void textBox1_MouseEnter(object sender, EventArgs e)

{

this.timer1.Stop();

}

private void textBox1_MouseLeave(object sender, EventArgs e)

{

this.timer1.Start();

}

}

}