Question

我正在尝试构建一个事件管理应用程序。我有一个带月历的窗口。这就是DataGridView的样子：

每个单元格代表一个月份，如果当天安排了一个或多个事件，则该单元格必须为绿色。我使用以下setter：

public IList<Event> _EventsByMonth
{//this setter populates and colors the table
    set
    {
        eventsByMonth = value;


        dgvEventsByMonth.Rows.Add("", "", "", "", "", "", "");
        dgvEventsByMonth.Rows.Add("", "", "", "", "", "", "");
        dgvEventsByMonth.Rows.Add("", "", "", "", "", "", "");
        dgvEventsByMonth.Rows.Add("", "", "", "", "", "", "");
        dgvEventsByMonth.Rows.Add("", "", "", "", "", "", "");
        //dgvEventsByMonth.Rows.Add("", "", "", "", "", "", "");


        foreach (DataGridViewRow row in dgvEventsByMonth.Rows)
        {
            row.Height = (dgvEventsByMonth.ClientRectangle.Height - dgvEventsByMonth.ColumnHeadersHeight) / dgvEventsByMonth.Rows.Count;
        }


        if (eventsByMonth.Count != 0)
        {
            DateTime aux = new DateTime();


            mapMonthDaysToEvents();

            {
                //in case the first event in the list is recurrent, the following method is necessary
                aux = getNextOccurrenceDateOrStartDate(eventsByMonth[0]);
                //I need to know which is the first weekday of the month 
                aux = aux.AddDays(1 - eventsByMonth[0].startDatetime.Day);
            }

            int firstWeekDayOfTheMonth = (int)aux.DayOfWeek;
            int numberOfDays = DateTime.DaysInMonth(aux.Year, aux.Month);

            for (int i = 0, DaysIterator = 1; DaysIterator <= numberOfDays; i++)
            {
                for (int j = 0; j < 7; j++)
                {
                    //go over the uncovered days at the beginning of the calendar
                    while (i == 0 && j + 1 < firstWeekDayOfTheMonth)
                    {
                        j += 1;
                    }

                    dgvEventsByMonth.Rows[i].Cells[j].Value = DaysIterator;

                    //TODO check for events in that day. if any, color the cell
                    /*if (mappingOfMonthDaysToEventsByMonth[DaysIterator] != null)
                    {
                        dgvEventsByDay.Rows[i].Cells[j].Style.BackColor = Color.Green;
                    }*/

                    DaysIterator++;
                }
            } 
        }
        dgvEventsByMonth.Refresh();
    }
}

除了设置私有字段eventsByMonth之外，还应该为datagridview填充和着色。上面的日历窗口图像是在以下代码片段被评论时产生的：

                    //TODO check for events in that day. if any, color the cell
                    /*if (mappingOfMonthDaysToEventsByMonth[DaysIterator] != null)
                    {
                        dgvEventsByDay.Rows[i].Cells[j].Style.BackColor = Color.Green;
                    }*/

取消注释相同的代码时抛出以下异常：

Exception thrown: 'System.ArgumentOutOfRangeException' in mscorlib.dll
System.Transactions Critical: 0 : <TraceRecord xmlns="http://schemas.microsoft.com/2004/10/E2ETraceEvent/TraceRecord" Severity="Critical"><TraceIdentifier>http://msdn.microsoft.com/TraceCodes/System/ActivityTracing/2004/07/Reliability/Exception/Unhandled</TraceIdentifier><Description>Unhandled exception</Description><AppDomain>EventManagementApplication.vshost.exe</AppDomain><Exception><ExceptionType>System.ArgumentOutOfRangeException, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</ExceptionType><Message>Index was out of range. Must be non-negative and less than the size of the collection.
Parameter name: index</Message><StackTrace>   at System.Collections.ArrayList.get_Item(Int32 index)
   at System.Windows.Forms.DataGridViewCellCollection.get_Item(Int32 index)
   at EventManagementApplication.CalendarView.set__EventsByMonth(IList`1 value) in D:\probleme in C C++ Java PHP Python\probleme in C C++ Java PHP Python\C#\EventManagementApplication\EventManagementApplication\View\CalendarView.cs:line 225

问题是什么，因为有问题的片段之上的语句dgvEventsByMonth.Rows[i].Cells[j].Value = DaysIterator;从未引发异常？

抛出异常时i == 3，j == 5，DaysIterator == 23.

我应该尝试其他方法为细胞着色吗？我不想被困在这个上面。对我而言，让事情发挥作用比解决这类问题更重要。

Answer 1

您遍历dgvEventsByMonth，但在dgvEventsByDay中为单元格设置样式。据我了解，你需要更换它

Answer 2

通过跟踪和堆栈转储，这必须从索引引用参数传入DataGridView。代码中没有任何内容可以确保dgvEventsByDay具有与dgvEventsByMonth相同的行数和列数，因此我猜测它的最大行数，列索引小于（3,5）。

据推测，(mappingOfMonthDaysToEventsByMonth[DaysIterator] != null)测试并不总是回归真实，但这失败了，因为这是第一次尝试将背景设置在它的真实边界之外。

尝试更改dataGridView中单元格的颜色时出现System.ArgumentOutOfRangeException

2 个答案: