文字录入无限制Undo,Redo的实现

这里只针对Edit的内容做一个简单的undo，redo功能；

原理就是，将新增字符和相关信息添加到undo列表，在undo动作时，取记录信息，并在edit中删除新增的字符，然后将此动作添加到redo列表，以便恢复。

 

本程序只对文本框文字的顺序增加做了处理，对于任意位置的删除，复制粘贴等没有进行处理，大家可以根据实际情况完善，增加辅助信息来完成对撤销和恢复的操作。

 

明白了原理，对于其他的操作都是这个道理，比如你画图什么的，保留每个图形的相关信息，然后撤销恢复重画，说的简单，做起来还是需要我们动脑子的^_^

 

为方便查看，将所有代码写到了一个单元。

 

Delphi代码

unit Unit1;interfaceuses Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms, Dialogs, StdCtrls;type TUndoInfo = record sText : String; //每次增加的新字符串，不是整个edit的字符串 iLastLen : Integer;//上一次edit内容的长度 end; PUndoInfo = ^TUndoInfo; TForm1 = class(TForm) Edit1: TEdit; btn_undo: TButton; btn_redo: TButton; procedure FormCreate(Sender: TObject); procedure Edit1Change(Sender: TObject); procedure btn_undoClick(Sender: TObject); procedure btn_redoClick(Sender: TObject); private { Private declarations } FUnDoList : TList; //undo列表 FReDoList : TList; //redo列表 //添加到undo列表，s:新字符串,lastlen:上一次整个长度 procedure AddUnDoAction(s:String;lastlen:Integer); //添加到redo列表 procedure AddReDoAction(p:PUndoInfo); public { Public declarations } end;var Form1: TForm1;implementation{$R *.dfm}{ TForm1 }procedure TForm1.AddUnDoAction(s: String;lastlen:Integer);var p:PUndoInfo;begin New(p); p.sText := s; p.iLastLen := lastlen + Length(s); FUnDoList.Add(p);end;procedure TForm1.FormCreate(Sender: TObject);begin FUnDoList := TList.Create; FReDoList := TList.Create; //添加初始值 AddUnDoAction(Edit1.Text,0);end;{这里只简单的在OnChange事件中来添加 undo内容，实际应用中比这要复杂的多，这里只在这里说明一下简单应用}procedure TForm1.Edit1Change(Sender: TObject);var lastlen:Integer; s:String;begin //先取得上一次的最后长度 lastlen := PUndoInfo(FUnDoList.Items[FUnDoList.Count - 1]).iLastLen; //本次新录入的字符串 s := Copy(Edit1.Text,lastlen+1,Length(Edit1.Text)-lastlen); //添加到undo列表 AddUnDoAction(s,lastlen);end;procedure TForm1.btn_undoClick(Sender: TObject);var s,ts:string; lastlen:Integer;begin //先取消OnChange事件，否则当修改edit的内容时，会重复触发OnChange事件，导致错误 Edit1.OnChange := nil; //因为最后一个是原始值，所以这里判断是否大于1 if FUnDoList.Count > 1 then begin s := Edit1.Text; //取上次的值 ts := PUndoInfo(FUnDoList.Items[FUnDoList.Count - 1]).sText; lastlen := PUndoInfo(FUnDoList.Items[FUnDoList.Count - 1]).iLastLen; //重新赋给edit内容 Delete(s,lastlen,Length(ts)); Edit1.Text := s; //添加到redo AddReDoAction(FUnDoList.Items[FUnDoList.Count - 1]); //将该项移出undo列表 FUnDoList.Delete(FUnDoList.Count - 1); end; //回复OnChange事件 Edit1.OnChange := Self.Edit1Change;end;procedure TForm1.AddReDoAction(p:PUndoInfo);begin FReDoList.Add(p);end;//重复动作，原理同撤销动作procedure TForm1.btn_redoClick(Sender: TObject);var s,ts:string; lastlen:Integer;begin Edit1.OnChange := nil; if FReDoList.Count > 0 then begin ts := PUndoInfo(FReDoList.Items[FReDoList.Count - 1]).sText; lastlen := PUndoInfo(FReDoList.Items[FReDoList.Count - 1]).iLastLen; Edit1.Text := Edit1.Text + ts; FUnDoList.Add(PUndoInfo(FReDoList.Items[FReDoList.Count - 1])); FReDoList.Delete(FReDoList.Count - 1); end; Edit1.OnChange := Self.Edit1Change;end;end.

 

C#代码

using System;using System.Collections.Generic;using System.ComponentModel;using System.Data;using System.Drawing;using System.Text;using System.Windows.Forms;namespace Test_CSharp_Win{ public partial class Form2 : Form { List<UnDoInfo> undoList; List<UnDoInfo> redoList; public Form2() { InitializeComponent(); undoList = new List<UnDoInfo>(); redoList = new List<UnDoInfo>(); //添加初始值 AddUnDoAction(textBox1.Text, 0); } /// <summary> /// //添加到undo列表 /// </summary> /// <param name="s">新字符串</param> /// <param name="lastlen">上一次整个长度</param> private void AddUnDoAction(string s, int lastlen) { UnDoInfo info = new UnDoInfo(); info.sText = s; info.iLastLen = lastlen + s.Length; undoList.Add(info); } /// <summary> /// 添加到redo列表 /// </summary> /// <param name="info"></param> private void AddReDoAction(UnDoInfo info) { redoList.Add(info); } private void textBox1_TextChanged(object sender, EventArgs e) { string s = string.Empty; int lastlen = 0; //先取得上一次的最后长度 lastlen = undoList[undoList.Count - 1].iLastLen; //本次新录入的字符串 s = textBox1.Text.Substring(lastlen, textBox1.Text.Length - lastlen); //添加到undo列表 AddUnDoAction(s, lastlen); } private void btn_undo_Click(object sender, EventArgs e) { string s = string.Empty; string ts = string.Empty; int lastlen = 0; //先取消TextChanged事件，否则当修改edit的内容时，会重复触发TextChanged事件，导致错误 textBox1.TextChanged -= this.textBox1_TextChanged; //因为最后一个是原始值，所以这里判断是否大于1 if (undoList.Count > 1) { s = textBox1.Text; ts = undoList[undoList.Count - 1].sText; lastlen = undoList[undoList.Count - 1].iLastLen; s = s.Remove(lastlen-1, ts.Length); textBox1.Text = s; //添加到redo AddReDoAction(undoList[undoList.Count - 1]); //将该项移出undo列表 undoList.RemoveAt(undoList.Count - 1); } //恢复TextChanged事件 textBox1.TextChanged += this.textBox1_TextChanged; } /// <summary> /// 重复动作，原理同撤销动作 /// </summary> /// <param name="sender"></param> /// <param name="e"></param> private void btn_redo_Click(object sender, EventArgs e) { string ts = string.Empty; int lastlen = 0; textBox1.TextChanged -= this.textBox1_TextChanged; if (redoList.Count > 0) { ts = redoList[redoList.Count - 1].sText; lastlen = redoList[redoList.Count - 1].iLastLen; textBox1.Text = textBox1.Text + ts; undoList.Add(redoList[redoList.Count - 1]); redoList.RemoveAt(redoList.Count - 1); } textBox1.TextChanged += this.textBox1_TextChanged; } } struct UnDoInfo { //每次增加的新字符串，不是整个edit的字符串 public string sText; //上一次edit内容的长度 public int iLastLen; }}

 

VC代码

头文件{DataDefined.h}struct UnDoInfo{CString sText;int iLastLen;};CArray<UnDoInfo*,UnDoInfo*&> undoList;CArray<UnDoInfo*,UnDoInfo*&> redoList;void AddUnDoAction(CString s,int lastlen);void AddReDoAction(UnDoInfo* info);主cpp文件，其中要为CEdit指定内容变化响应事件{ON_EN_CHANGE(IDC_EDIT1, &CTest_c_MFCDlg::OnEnChangeEdit1)}#include "DataDefined.h"BOOL CTest_c_MFCDlg::OnInitDialog(){CDialog::OnInitDialog();//这里省略自动生成代码// TODO: 这里添加初始的信息CEdit* edit = (CEdit*)GetDlgItem(IDC_EDIT1);CString s;edit->GetWindowTextW(s);AddUnDoAction(s,0);return TRUE; // 除非将焦点设置到控件，否则返回 TRUE}bool canchange = true; //这个控制是否触发CEdit的内容变化事件//添加到undo列表，s:新字符串,lastlen:上一次整个长度void AddUnDoAction(CString s,int lastlen){UnDoInfo* info = new UnDoInfo;info->iLastLen = lastlen + s.GetLength();info->sText = s;undoList.Add(info);}//添加到redo列表void AddReDoAction(UnDoInfo* info){redoList.Add(info);}//undo按钮点击事件void CTest_c_MFCDlg::OnBnClickedundo(){// TODO: 在此添加控件通知处理程序代码canchange = false;CString s,ts;int lastlen;CEdit* edit = (CEdit*)GetDlgItem(IDC_EDIT1);if (undoList.GetCount() > 1){edit->GetWindowTextW(s);ts = undoList.GetAt(undoList.GetCount()-1)->sText;lastlen = undoList.GetAt(undoList.GetCount() - 1)->iLastLen;if (lastlen > 0)s.Delete(lastlen-1,ts.GetLength());elses = "";edit->SetWindowTextW(s);AddReDoAction(undoList.GetAt(undoList.GetCount() - 1));undoList.RemoveAt(undoList.GetCount() - 1);}canchange = true;}//redo按钮点击事件void CTest_c_MFCDlg::OnBnClickedredo(){// TODO: 在此添加控件通知处理程序代码canchange = false;CString s,ts;int lastlen;CEdit* edit = (CEdit*)GetDlgItem(IDC_EDIT1);if (redoList.GetCount() > 0){edit->GetWindowTextW(s);ts = redoList.GetAt(redoList.GetCount() - 1)->sText;lastlen = redoList.GetAt(redoList.GetCount() - 1)->iLastLen;edit->SetWindowTextW(s + ts);undoList.Add(redoList.GetAt(redoList.GetCount() - 1));redoList.RemoveAt(redoList.GetCount() - 1);}canchange = true;}//CEdit的change处理代码void CTest_c_MFCDlg::OnEnChangeEdit1(){// TODO: 如果该控件是 RICHEDIT 控件，则它将不会// 发送该通知，除非重写 CDialog::OnInitDialog()// 函数并调用 CRichEditCtrl().SetEventMask()，// 同时将 ENM_CHANGE 标志“或”运算到掩码中。// TODO: 在此添加控件通知处理程序代码if (!canchange) return;CString s;int lastlen;lastlen = ((UnDoInfo*)undoList.GetAt(undoList.GetCount()-1))->iLastLen;CEdit* edit = (CEdit*)GetDlgItem(IDC_EDIT1);edit->GetWindowTextW(s);s = s.Mid(lastlen,s.GetLength()-lastlen);AddUnDoAction(s,lastlen);}