自己弄了一个上下文菜单

 为完成《Windows Forms编程实战》第175页的“尝试一下”，特制ContextMenuStrip，有BUG请指评，谢谢！
 使用： 可直接new一个，在参数中填TextBox类实例即可。

Code在此
  1public class MyContextMenuStrip : System.Windows.Forms.ContextMenuStrip
  2    {
  3        /**//// <summary>
  4        /// 剪切按钮
  5        /// </summary>
  6        System.Windows.Forms.ToolStripMenuItem TSMI_Cut = 
  7            new System.Windows.Forms.ToolStripMenuItem();
  8
  9        /**//// <summary>
 10        /// 复制按钮
 11        /// </summary>
 12        System.Windows.Forms.ToolStripMenuItem TSMI_Copy = 
 13            new System.Windows.Forms.ToolStripMenuItem();
 14
 15        /**//// <summary>
 16        /// 粘贴按钮
 17        /// </summary>
 18        System.Windows.Forms.ToolStripMenuItem TSMI_Paste = 
 19            new System.Windows.Forms.ToolStripMenuItem();
 20
 21        /**//// <summary>
 22        /// 删除按钮
 23        /// </summary>
 24        System.Windows.Forms.ToolStripMenuItem TSMI_Delete = 
 25            new System.Windows.Forms.ToolStripMenuItem();
 26
 27        /**//// <summary>
 28        /// 撤销按钮
 29        /// </summary>
 30        System.Windows.Forms.ToolStripMenuItem TSMI_Undo = 
 31            new System.Windows.Forms.ToolStripMenuItem();
 32
 33        /**//// <summary>
 34        /// 全选按钮
 35        /// </summary>
 36        System.Windows.Forms.ToolStripMenuItem TSMI_SelectAll =
 37            new System.Windows.Forms.ToolStripMenuItem();
 38
 39        /**//// <summary>
 40        /// 上分隔条
 41        /// </summary>
 42        System.Windows.Forms.ToolStripSeparator TSS_Up =
 43            new System.Windows.Forms.ToolStripSeparator();
 44
 45        /**//// <summary>
 46        /// 下分隔条
 47        /// </summary>
 48        System.Windows.Forms.ToolStripSeparator TSS_Down =
 49            new System.Windows.Forms.ToolStripSeparator();
 50
 51        /**//// <summary>
 52        /// 构造函数
 53        /// </summary>
 54        protected MyContextMenuStrip()
 55        {
 56            this.InitializeComponent();
 57
 58            this.Items.AddRange(new System.Windows.Forms.ToolStripItem[]{
 59                this.TSMI_Undo,
 60                this.TSS_Up,
 61                this.TSMI_Cut,
 62                this.TSMI_Copy,
 63                this.TSMI_Paste,
 64                this.TSMI_Delete,
 65                this.TSS_Down,
 66                this.TSMI_SelectAll
 67            });
 68
 69            this.InitItemEnableInMyCMS();
 70        }
 71
 72        /**//// <summary>
 73        /// 构造函数
 74        /// </summary>
 75        /// <param name="myControl">TextBoxBase类实例</param>
 76        public MyContextMenuStrip(System.Windows.Forms.TextBoxBase myControl)
 77            : this()
 78        {
 79            this.myCMS_Object = myControl;
 80
 81            this.myCMS_Object.MouseDown +=
 82                new System.Windows.Forms.MouseEventHandler(this.myCMS_Object_MouseDown);
 83
 84            this.myCMS_Object.Click +=
 85                new System.EventHandler(this.myCMS_Object_Click);
 86
 87            this.Opened +=
 88                new System.EventHandler(this.myCMS_Opened);
 89        }
 90
 91        /**//// <summary>
 92        /// TextBoxBase实例字段
 93        /// </summary>
 94        private System.Windows.Forms.TextBoxBase myCMS_Object;
 95
 96        /**//// <summary>
 97        /// TextBoxBase实例属性
 98        /// </summary>
 99        public System.Windows.Forms.TextBoxBase MyCMS_Object
100        {
101            get { return myCMS_Object; }
102            set { myCMS_Object = value; }
103        }
104
105        /**//// <summary>
106        /// 
107        /// </summary>
108        private int Integer = 0;
109
110        /**//// <summary>
111        /// 初始化上下文菜单项
112        /// </summary>
113        private void InitializeComponent()
114        {
115            // 
116            // TSMI_Undo
117            // 
118            this.TSMI_Undo.Name = "TSMI_Undo";
119            this.TSMI_Undo.Size = new System.Drawing.Size(152, 22);
120            this.TSMI_Undo.Text = "撤销";
121            this.TSMI_Undo.Click += new EventHandler(this.TSMI_Undo_Click);
122            // 
123            // TSS_Up
124            // 
125            this.TSS_Up.Name = "TSS_Up";
126            this.TSS_Up.Size = new System.Drawing.Size(152, 22);
127            // 
128            // TSS_Down
129            // 
130            this.TSS_Down.Name = "TSS_Down";
131            this.TSS_Down.Size = new System.Drawing.Size(152, 22);
132            // 
133            // TSMI_Cut
134            // 
135            this.TSMI_Cut.Name = "TSMI_Cut";
136            this.TSMI_Cut.Size = new System.Drawing.Size(152, 22);
137            this.TSMI_Cut.Text = "剪切";
138            this.TSMI_Cut.Click += new EventHandler(this.TSMI_Cut_Click);
139            // 
140            // TSMI_Copy
141            // 
142            this.TSMI_Copy.Name = "TSMI_Copy";
143            this.TSMI_Copy.Size = new System.Drawing.Size(152, 22);
144            this.TSMI_Copy.Text = "复制";
145            this.TSMI_Copy.Click += new EventHandler(TSMI_Copy_Click);
146            // 
147            // TSMI_Paste
148            // 
149            this.TSMI_Paste.Name = "TSMI_Stick";
150            this.TSMI_Paste.Size = new System.Drawing.Size(152, 22);
151            this.TSMI_Paste.Text = "粘贴";
152            this.TSMI_Paste.Click += new EventHandler(this.TSMI_Paste_Click);
153            // 
154            // TSMI_SelectAll
155            // 
156            this.TSMI_SelectAll.Name = "TSMI_SelectAll";
157            this.TSMI_SelectAll.Size = new System.Drawing.Size(152, 22);
158            this.TSMI_SelectAll.Text = "全选";
159            this.TSMI_SelectAll.Click += new EventHandler(this.TSMI_SelectAll_Click);
160            // 
161            // TSMI_Delete
162            // 
163            this.TSMI_Delete.Name = "TSMI_Delete";
164            this.TSMI_Delete.Size = new System.Drawing.Size(152, 22);
165            this.TSMI_Delete.Text = "删除";
166            this.TSMI_Delete.Click += new EventHandler(this.TSMI_Delete_Click);
167        }
168        
169        /**//// <summary>
170        /// 撤销
171        /// </summary>
172        /// <param name="sender"></param>
173        /// <param name="e"></param>
174        private void TSMI_Undo_Click(object sender, EventArgs e)
175        {
176            // Determine if last operation can be undone in text box.   
177            if (this.myCMS_Object.CanUndo == true)
178            {
179                // Undo the last operation.
180                this.myCMS_Object.Undo();
181                // Clear the undo buffer to prevent last action from being redone.
182                this.myCMS_Object.ClearUndo();
183            }
184
185        }
186
187        /**//// <summary>
188        /// 剪切
189        /// </summary>
190        /// <param name="sender"></param>
191        /// <param name="e"></param>
192        private void TSMI_Cut_Click(object sender, EventArgs e)
193        {
194            // Ensure that text is currently selected in the text box.   
195            if (this.myCMS_Object.SelectedText != "")
196            {
197                // Cut the selected text in the control and paste it into the Clipboard.
198                this.myCMS_Object.Cut();
199            }
200        }
201
202        /**//// <summary>
203        /// 复制
204        /// </summary>
205        /// <param name="sender"></param>
206        /// <param name="e"></param>
207        private void TSMI_Copy_Click(object sender, EventArgs e)
208        {
209            if (this.myCMS_Object.SelectionLength > 0)
210            {
211                this.myCMS_Object.Copy();
212            }
213        }
214
215        /**//// <summary>
216        /// 粘贴
217        /// </summary>
218        /// <param name="sender"></param>
219        /// <param name="e"></param>
220        private void TSMI_Paste_Click(object sender, EventArgs e)
221        {
222            // Determine if there is any text in the Clipboard to paste into the text box.
223            if (System.Windows.Forms.Clipboard.GetDataObject().GetDataPresent(System.Windows.Forms.DataFormats.Text) == true)
224            {
225                // Determine if any text is selected in the text box.
226                if (this.myCMS_Object.SelectionLength > 0)
227                {
228                    // Ask user if they want to paste over currently selected text.
229                    if (System.Windows.Forms.MessageBox.Show("Do you want to paste over current selection?", "Cut Example", 
230                        System.Windows.Forms.MessageBoxButtons.YesNo) == System.Windows.Forms.DialogResult.No)
231                        // Move selection to the point after the current selection and paste.
232                        this.myCMS_Object.SelectionStart = this.myCMS_Object.SelectionStart + this.myCMS_Object.SelectionLength;
233                }
234                // Paste current text in Clipboard into text box.
235                this.myCMS_Object.Paste();
236            }
237        }
238
239        /**//// <summary>
240        /// 删除
241        /// </summary>
242        /// <param name="sender"></param>
243        /// <param name="e"></param>
244        private void TSMI_Delete_Click(object sender, EventArgs e)
245        {
246            this.myCMS_Object.SelectedText = string.Empty;
247        }
248
249        /**//// <summary>
250        /// 全选
251        /// </summary>
252        /// <param name="sender"></param>
253        /// <param name="e"></param>
254        private void TSMI_SelectAll_Click(object sender, EventArgs e)
255        {
256            // sender as System.Windows.Forms.TextBoxBase;
257            // Determine if any text is selected in the TextBox control.
258            if (this.myCMS_Object.SelectionLength == 0)
259                // Select all text in the text box.
260                this.myCMS_Object.SelectAll();
261
262            // Copy the contents of the control to the Clipboard.
263            this.myCMS_Object.Copy();
264
265        }
266
267        /**//// <summary>
268        /// 在控件上按下鼠标事件处理方法
269        /// </summary>
270        /// <param name="sender"></param>
271        /// <param name="e"></param>
272        private void myCMS_Object_MouseDown(object sender, System.Windows.Forms.MouseEventArgs e)
273        {
274            // this.myCMS_Object.ContextMenuStrip = this;
275            (sender as System.Windows.Forms.TextBoxBase).ContextMenuStrip = this;
276        }
277
278        /**//// <summary>
279        /// 单击控件事件处理方法
280        /// </summary>
281        /// <param name="sender"></param>
282        /// <param name="e"></param>
283        private void myCMS_Object_Click(object sender, EventArgs e)
284        {
285            if (this.Integer != 0)
286            {
287                this.myCMS_Object.SelectAll();
288            }
289            this.Integer = this.myCMS_Object.SelectionLength;
290        }
291
292        /**//// <summary>
293        /// 为控件设置输入焦点
294        /// </summary>
295        /// <param name="control">设置控件</param>
296        private void ControlSetFocus(System.Windows.Forms.Control control)
297        {
298            // 如果控件接受焦点，放置焦点到控件中。
299            if (control.CanFocus)
300            {
301                control.Focus();
302            }
303        }
304
305        当上下文菜单弹出事件处理方法#region 当上下文菜单弹出事件处理方法
306
307        /**//// <summary>
308        /// 当上下文菜单弹出事件处理方法
309        /// </summary>
310        /// <param name="sender"></param>
311        /// <param name="e"></param>
312        private void myCMS_Opened(object sender, EventArgs e)
313        {
314            // 让焦点进入控件this.myCMS_Object
315            this.ControlSetFocus(this.myCMS_Object);
316
317            this.myCMS_Object_OpenedMethod();
318        }
319
320        /**//// <summary>
321        /// 
322        /// </summary>
323        private void myCMS_Object_OpenedMethod()
324        {
325            this.InitItemEnableInMyCMS();
326
327            // 如果该控件中能否撤销前一操作
328            if (this.myCMS_Object.CanUndo == true)
329            {
330                this.TSMI_Undo.Enabled = true;
331            }
332
333            // 如果选中控件中的文本
334            if (this.myCMS_Object.SelectedText.Length > 0)
335            {
336                this.TSMI_Cut.Enabled = true;
337
338                this.TSMI_Copy.Enabled = true;
339
340                this.TSMI_Delete.Enabled = true;
341            }
342
343            // 如果剪切板中有文本字符
344            if (System.Windows.Forms.Clipboard.GetText().Length > 0)
345            {
346                this.TSMI_Paste.Enabled = true;
347            }
348
349            // 如果控件中不为空，则全选按钮使能为true
350            if (this.myCMS_Object.TextLength > 0)
351            {
352                this.TSMI_SelectAll.Enabled = true;
353            }
354
355        }
356
357        #endregion 当上下文菜单弹出事件处理方法
358
359        /**//// <summary>
360        /// 初始化选项按钮使能为false
361        /// </summary>
362        private void InitItemEnableInMyCMS()
363        {
364            try
365            {
366                foreach (System.Windows.Forms.ToolStripItem item in this.Items)
367                {
368                    // 因为this.Items中有分隔条TSS（ToolStripSeparator）类，
369                    // 与TSMI（ToolStripMenuItem）不同类，但由TSI（ToolStripItem）类直接和间接派生得来，
370                    // 所以做如下判断，若是TSS类，无使能属性。
371                    if(item is System.Windows.Forms.ToolStripMenuItem)
372                        item.Enabled = false;
373                }
374            }
375            catch (InvalidCastException ICex)
376            {
377            }
378        }
379    }