真心鬱悶，向上查詢兼替換行不通，有什麼辦法呢？再找找看，一定要找到向上替換的解決辦法！！

向上向下查詢好像都可以了吧，就是向上替換的時候就。...卡死就是後面還有一串字元是不在查詢內容的，可是就是這些內容讓人捉急了！！

不說了，貼程式碼。

        inout1,inout2  存放查詢數量的。

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 Notepad
{
    public partial class formFind : Form
    {
        public formFind()
        {
            InitializeComponent();
        }
 

        private void formFind_Load(object sender, EventArgs e)
        {
            text = ((Form1)this.Owner).RichrichTextBox1.Text;
            inout2 = text.Length;
            radioButton2.Checked = true;
        }

        string text = string.Empty;
        string f1 = string.Empty;
        public int a, b;
        public int inout1 = 0;
        public int inout2 = 0; //inout2 要放在Load賦值
 

        private void button1_Click(object sender, EventArgs e)
        {
            if (checkBox1.Checked == false) //是否區分大小寫
            {
                MatchSize();//呼叫小寫轉換
            }
            if (radioButton2.Checked == true)
            {
                DownSeek();//呼叫向下查詢
            }
            if (radioButton1.Checked == true)//向上查詢
            {
                UpSeek();呼叫向上查詢
            }
        }
 

        private void button2_Click(object sender, EventArgs e)
        {
            replace();//呼叫替換
        }

        private void button3_Click(object sender, EventArgs e)
        {
            if (checkBox1.Checked == false)  //是否區分大小寫
            {
                MatchSize();
            }

            //if (radioButton2.Checked == true)  //向下查詢
            //{
            //Form1 f1 = (Form1)this.Owner;
            //string f1_text = f1.RichTextBox1.Text;
            inout1 = 0; a = 0;
            a = text.IndexOf(textBox1.Text, inout1);
            for (int i = 0; i < a; i++)
            {
                DownSeek();
                replace();
            }
        }

        //關閉視窗
        private void button4_Click(object sender, EventArgs e)
        {
            this.Close();
        }

        private void checkBox1_CheckedChanged(object sender, EventArgs e)
        {
            if (checkBox1.Checked == true)
            {
                MatchSize();
            }
        }

        #region  自定義的--查詢----替換--
        /// <summary> 區分大小寫
        /// 轉換為小寫定義
        /// </summary>
        /// <param name="s"></param>
        /// <returns></returns>
        private void MatchSize()
        {
            Form1 f1 = (Form1)this.Owner;
            string f1_text = f1.RichrichTextBox1.Text;
            f1_text = f1_text.ToLower();//文字轉換為小寫
            textBox1.Text = textBox1.Text.ToLower(); //查詢內容轉換小寫
            //textBox2.Text = textBox2.Text.ToLower(); //替換字元轉換為小寫
        }

        /// <summary> -向下查詢-
        ///   自定義向下查詢字串 -向下查詢-
        /// </summary>
        /// <param name="s"></param>
        /// <returns></returns>
        private void DownSeek()
        {

            b = text.Length;
            inout2 = text.Length;
            Form1 f1 = (Form1)this.Owner;
            string f1_text = f1.RichrichTextBox1.Text;
            //inout1 = 0;
            a = f1_text.IndexOf(textBox1.Text, inout1); //向下查詢
            if (a >= 0)
            {
                f1.RichrichTextBox1.Select(a, textBox1.Text.Length);
                f1.RichrichTextBox1.Focus();
                inout1 = ++a;
            }
            else
            {
                MessageBox.Show(this.Owner,
                    "查詢不到" + "\"" + textBox1.Text + "\"",
                    "-Mxdr記事本",
                    MessageBoxButtons.OK,
                    MessageBoxIcon.Asterisk,
                    MessageBoxDefaultButton.Button1);
                //return;
                a = 0;
                inout1 = 0;
            }
        }

        /// <summary> --向上查詢--
        ///   自定義向上查詢字串 --向上查詢--
        /// </summary>
        /// <param name="s"></param>
        /// <returns></returns>
        private void UpSeek()
        {
            a = 0;
            inout1 = 0;
            Form1 f1 = (Form1)this.Owner;
            string f1_text = f1.RichrichTextBox1.Text;
            //inout2 = 0;
            b = f1_text.LastIndexOf(textBox1.Text, inout2);
            if (b >= 0)
            {
                f1.RichrichTextBox1.Select(b, textBox1.Text.Length);
                f1.RichrichTextBox1.Focus();
                inout2 = --b;

            }
            else
            {
                MessageBox.Show(this.Owner,
                    "查詢不到" + "\"" + textBox1.Text + "\"",
                    "-Mxdr記事本",
                    MessageBoxButtons.OK,
                    MessageBoxIcon.Asterisk,
                    MessageBoxDefaultButton.Button1);
                //return;
                b = text.Length;
                inout2 = text.Length;
            }
        }

        /// <summary>  --替換--自定義
        /// --替換--  自定義替換字串
        /// </summary>
        /// <param name="s"></param>
        /// <returns></returns>
        private void replace()
        {
            Form1 f1 = (Form1)this.Owner;
            if (f1.RichrichTextBox1.SelectedText.Length > 0)
                f1.RichrichTextBox1.SelectedText = this.textBox2.Text;//textBox2中放要替換的字元
        }
        #endregion

    }
}

。。。。。。。。。。。。

。。。。。。。。。。。。
就下面這段是沒辦法除錯通過的

       private void button3_Click(object sender, EventArgs e)
        {
            if (checkBox1.Checked == false)  //是否區分大小寫
            {
                MatchSize();
            }
         
            inout1 = 0; a = 0;
            a = text.IndexOf(textBox1.Text, inout1);
            for (int i = 0; i < a; i++)
            {
                DownSeek();
                replace();
            }
           // b = f1_text.LastIndexOf(textBox1.Text, inout2);
           // 
           // for (int i = 0; i < b; i++)
            //{
            //    UpSeek();
            //    replace();
            //}
        }