小编use*_*971的帖子

我想在C#代码中显示确认框.我已经看到了上面的解决方案,但它在'Yes'显示异常,因为'System.Nullable'不包含'Yes'的定义.我该如何删除此错误？

 private void listBox1_MouseRightButtonDown(object sender, MouseButtonEventArgs e)
    {
        if (sender is ListBoxItem)
        {
            ListBoxItem item = (ListBoxItem)sender;
            Harvest_TimeSheetEntry entryToDelete = (Harvest_TimeSheetEntry)item.DataContext;

            DialogResult dialogResult = System.Windows.Forms.MessageBox.Show("Are you sure?", "Delete Confirmation", MessageBoxButtons.YesNo);

            if (dialogResult == DialogResult.Yes)  // error is here
            {
                Globals._globalController.harvestManager.deleteHarvestEntry(entryToDelete);
            }
            else
            {
                System.Windows.MessageBox.Show("Delete operation Terminated");
            }

        }
    }

我想以编程方式将上下文菜单添加到我的托盘图标,这样当我右键单击托盘图标时,它应该显示菜单.如何为托盘图标编写右键单击事件处理程序？

我试过以下:

private void Icon_MouseRightClick(object sender, MouseButtonEventArgs e)
{
 if (e.Button == System.Windows.Forms.MouseButtons.Left)  // shows error ate button
 {
   return;
 }
 if (e.Button == System.Windows.Forms.MouseButtons.Right)
 {
   // code for adding context menu
 }
}

声明Eventhandler为,

NotifyIcon.MouseRightClick += new MouseButtonEventHandler(NotifyIcon_MouseRightClick);

在我的应用程序中,我不明白如何处理system.format异常.见下面的代码

public Harvest_Project(XmlNode node)
    {
        this._node = node;
        this._name = node.SelectSingleNode("name").InnerText;

        this._created_at = storeTime(node.SelectSingleNode("created-at").InnerText);
        this._updated_at = storeTime(node.SelectSingleNode("updated-at").InnerText);
        this._over_budget_notified_at = storeTime(node.SelectSingleNode("over-budget-notified-at").InnerText);
        this._latest_record_at = storeTime(node.SelectSingleNode("hint-latest-record-at").InnerText);
        this._earliest_record_at = storeTime(node.SelectSingleNode("hint-earliest-record-at").InnerText);

        this._billable = bool.Parse(node.SelectSingleNode("billable").InnerText);

        try
        {
                this._id = Convert.ToInt32(node.SelectSingleNode("id").InnerText);
                this._client_id = Convert.ToInt32(node.SelectSingleNode("client-id").InnerText);
                this._budget = float.Parse(node.SelectSingleNode("budget").InnerText);
                this._fees = Convert.ToInt32(getXmlNode("fees", node));

        }
        catch (FormatException e)
        {

           Console.WriteLine();
        }
        catch (OverflowException e)
        {
            Console.WriteLine("The number cannot fit in an Int32.");
        }

        this._code = node.SelectSingleNode("code").InnerText;
        this._notes = node.SelectSingleNode("notes").InnerText;

    }

在这里,尝试并捕获块,所有节点都采用int值,但是,因为_fees取"0"值.它显示了格式异常.我只是希望我的节点不显示空字符串.我想处理这个异常.这意味着,它不应该在"this._fees = Convert.ToInt32(getXmlNode("fees",node))"行中抛出异常;" 因为它返回了我想要的int值.

我怎么能实现这一目标？