使用断点时文本框中的值未显示

Question

我在下面有两个textchanged代码：

#region Tasklist Percentage
    private void TaskListAccomplishmentPrcentagetextBox_TextChanged(object sender, EventArgs e)
    {
        string tl = TaskListAccomplishmentPercentagetextBox.Text;//breakpoint here(has value)
        if (tl != null)
        {
            if(tl == "0%")
            {
                TaskListAccomplishmentPercentagetextBox.BackColor = Color.FromArgb(255, 150, 150);
                TaskListAccomplishmentPercentagetextBox.ForeColor = Color.FromArgb(0, 0, 0);
            }
            else if (tl == "100%")
            {
                TaskListAccomplishmentPercentagetextBox.BackColor = Color.FromArgb(0, 204, 0);
                TaskListAccomplishmentPercentagetextBox.ForeColor = Color.FromArgb(0, 0, 0);
            }
            else if (tl == "N/A")
            {
                TaskListAccomplishmentPercentagetextBox.BackColor = Color.FromArgb(0, 204, 0);
                TaskListAccomplishmentPercentagetextBox.ForeColor = Color.FromArgb(0, 0, 0);
            }
        }
    }
    #endregion

    #region Compute Total Completion Percentage
    private void TotalCompletionPercentagetextBox_TextChanged(object sender, EventArgs e)
    {
        string tl = TaskListAccomplishmentPercentagetextBox.Text;//if breakpoint is here(has null value)
        string lpi = SLACompliancePercentageLPItextBox.Text;            
    }
    #endregion

当我在任务列表区域TaskListAccomplishmentPercentagetextBox.Text上的断点值显示0%但是当我在计算总点击区域TaskListAccomplishmentPercentagetextBox.Text上放置断点时，值显示 null或空的。

TaskListAccomplishmentPercentagetextBox.Text的用户输入值为0%，显示何时运行该程序。问题是显示的计算区域的值，我无法使用它来创建计算。

我是否必须声明值，调用等值以手动显示在计算总区域中？在我的其他textchanged计算中导致此问题不会发生。任何帮助或意见都表示赞赏。