如何將上下文菜單添加到ListBoxItem？

Question

我有一個列表框，我想爲列表中的每個項目添加一個上下文菜單。我已經看到了「解決方案」，如果在空白區域右鍵單擊選擇一個項目並禁用上下文菜單，但此解決方案感覺很髒。

有誰知道更好的方法？

Answer 1

這樣的菜單旁邊彈出鼠標

private string _selectedMenuItem; 
private readonly ContextMenuStrip collectionRoundMenuStrip; 

public Form1() 
{ 
    var toolStripMenuItem1 = new ToolStripMenuItem {Text = "Copy CR Name"}; 
    toolStripMenuItem1.Click += toolStripMenuItem1_Click; 
    var toolStripMenuItem2 = new ToolStripMenuItem {Text = "Get information on CR"}; 
    toolStripMenuItem2.Click += toolStripMenuItem2_Click; 
    collectionRoundMenuStrip = new ContextMenuStrip(); 
    collectionRoundMenuStrip.Items.AddRange(new ToolStripItem[] {toolStripMenuItem1, toolStripMenuItem2 }); 
    listBoxCollectionRounds.MouseDown += listBoxCollectionRounds_MouseDown; 
} 

private void toolStripMenuItem2_Click(object sender, EventArgs e) 
{ 
    var info = GetInfoByName(_selectedMenuItem); 
    MessageBox.Show(info.Name + Environment.NewLine + info.Date); 
} 

private void toolStripMenuItem1_Click(object sender, EventArgs e) 
{ 
    Clipboard.SetText(_selectedMenuItem); 
} 

private void myListBox_MouseDown(object sender, MouseEventArgs e) 
{ 
    if (e.Button != MouseButtons.Right) return; 
    var index = myListBox.IndexFromPoint(e.Location); 
    if (index != ListBox.NoMatches) 
    { 
     _selectedMenuItem = listBoxCollectionRounds.Items[index].ToString(); 
     collectionRoundMenuStrip.Show(Cursor.Position); 
     collectionRoundMenuStrip.Visible = true; 
    } 
    else 
    { 
     collectionRoundMenuStrip.Visible = false; 
    } 
} 

Answer 2

沒有其他方法：上下文菜單不屬於列表框中的項目，而是由列表框本身擁有。它與樹視圖控件類似，它也擁有上下文菜單而不是treenode。因此，無論何時選擇列表框中的項目，都應根據所選項目設置列表框的上下文菜單。

Answer 3

只是爲了詳細闡述一下Frans的說法......即使ListBox擁有ContextMenuStrip，您仍然可以在打開時自定義菜單條中的項目。因此基於列表框中的鼠標位置來定製它的內容。
下面的示例基於右鍵單擊選擇列表框中的項目，然後根據用戶右鍵單擊的項目自定義上下文菜單條。這是一個簡單的例子，但應該讓你去：一個列表框添加到窗體，並添加以下代碼：

print("  #region Private Members 
    private ContextMenuStrip listboxContextMenu; 
    #endregion 

    private void Form1_Load(object sender, EventArgs e) 
    { 
     //assign a contextmenustrip 
     listboxContextMenu = new ContextMenuStrip(); 
     listboxContextMenu.Opening +=new CancelEventHandler(listboxContextMenu_Opening); 
     listBox1.ContextMenuStrip = listboxContextMenu; 

     //load a listbox 
     for (int i = 0; i < 100; i++) 
     { 
      listBox1.Items.Add("Item: " + i); 
     } 
    } 

    private void listBox1_MouseDown(object sender, MouseEventArgs e) 
    { 
     if (e.Button == MouseButtons.Right) 
     { 
      //select the item under the mouse pointer 
      listBox1.SelectedIndex = listBox1.IndexFromPoint(e.Location); 
      if (listBox1.SelectedIndex != -1) 
      { 
       listboxContextMenu.Show(); 
      }     
     } 
    } 

    private void listboxContextMenu_Opening(object sender, CancelEventArgs e) 
    { 
     //clear the menu and add custom items 
     listboxContextMenu.Items.Clear(); 
     listboxContextMenu.Items.Add(string.Format("Edit - {0}", listBox1.SelectedItem.ToString())); 
    } "); 

希望可以幫助。 -Mike

Answer 4

如果它只是啓用或禁用上下文菜單項的問題，它可能是更有效的只有做時，上下文菜單中啓動，而不是每次都在列表框中選擇的變化：

myListBox.ContextMenu.Popup += new EventHandler(myContextPopupHandler); 


private void myContextPopupHandler(Object sender, System.EventArgs e) 
{ 
    if (SelectedItem != null) 
    { 
     ContextMenu.MenuItems[1].Enabled = true; 
     ContextMenu.MenuItems[2].Enabled = true; 
    } 
    else 
    { 
     ContextMenu.MenuItems[1].Enabled = false; 
     ContextMenu.MenuItems[2].Enabled = false; 
    } 
} 

Answer 5

在XAML是這樣表示：

<ListBox> 
    <ListBox.ContextMenu> 
     <ContextMenu> 
      <MenuItem Header="Add User..."/> 
      <MenuItem Header="Edit..."/> 
      <MenuItem Header="Disable"/> 
     </ContextMenu> 
    </ListBox.ContextMenu> 
</ListBox> 

Answer 6

這一個是最好的...

using System.Windows.Forms; 

ContextMenuStrip menu; 

this.menu.Items.AddRange(new ToolStripItem[] { this.menuItem }); 
this.listBox.MouseUp += new MouseEventHandler(this.mouse_RightClick); 

private void mouse_RightClick(object sender, MouseEventArgs e) 
{ 
    int index = this.listBox.IndexFromPoint(e.Location); 
    if (index != ListBox.NoMatches) 
    { 
     menu.Visible = true; 
    } 
    else 
    { 
     menu.Visible = false; 
    } 
} 

Answer 7

//Create and Initialize the contextMenuStrip component 
contextMenuStrip_ListaAulas = new ContextMenuStrip(); 

//Adding an Item 
contextMenuStrip_ListaAulas.Items.Add("Modificar"); 

//Binding the contextMenuStrip with the ListBox 
listBox_Aulas.ContextMenuStrip = contextMenuStrip_ListaAulas; 

//The solution below 
if (e.Button == System.Windows.Forms.MouseButtons.Right) 
{ 
    //select the item under the mouse pointer 
    listBox_Aulas.SelectedIndex = listBox_Aulas.IndexFromPoint(e.Location); 

    //if the selected index is an item, binding the context MenuStrip with the listBox 
    if (listBox_Aulas.SelectedIndex != -1) 
    { 
     listBox_Aulas.ContextMenuStrip = contextMenuStrip_ListaAulas; 
    } 
    //else, untie the contextMenuStrip to the listBox 
    else 
    { 
     listBox_Aulas.ContextMenuStrip = null; 
    } 
} 

Answer 8

而且這是我的解決方案：

listBox_Usernames.ContextMenuStrip = contextMenuStripRemove; 

    listBox_Usernames.MouseUp += new MouseEventHandler(listBox_Usernames_MouseUp); 

    void listBox_Usernames_MouseUp(object sender, MouseEventArgs e) 
    { 
     int index = listBox_Usernames.IndexFromPoint(e.Location); 

     if (e.Button == System.Windows.Forms.MouseButtons.Right) 
     { 
      if (index != ListBox.NoMatches) 
      { 
       if (listBox_Usernames.SelectedIndex == index) 
       { 
        listBox_Usernames.ContextMenuStrip.Visible = true; 
       } 
       else 
       { 
        listBox_Usernames.ContextMenuStrip.Visible = false; 

       } 
      } 
      else 
      { 
       listBox_Usernames.ContextMenuStrip.Visible = false; 
      } 
     } 
     else 
     { 
      listBox_Usernames.ContextMenuStrip.Visible = false; 

     } 
    } 

Answer 9

我喜歡這個，這個作品對我來說是偉大而快速的。

private void contextMenuStrip1_Opening(object sender, CancelEventArgs e) 
    { 
     if (Listbox.SelectedItem == null) 
      e.Cancel = true; 
    } 

Answer 10

在代碼（多爲綁定）一個行：

var datasource = new BindingList<string>(new List<string>(new string[] { "item1" })); 
listbox.DataSource = datasource ; 
listbox.ContextMenu = new ContextMenu(
    new MenuItem[] { 
     new MenuItem("Delete", 
      new EventHandler((s,ev) => 
      datasource.Remove(listbox.SelectedItem.ToString()) 
     ) 
    ) 
}); 

private void buttonAdd_Click(object sender, EventArgs e) 
{ 
    datasource.Add(textBox.Text); 
}