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

Question

我正在尝试构建事件管理应用程序。我有一个带有月历的 window。这是 DataGridView 的样子：

每个单元格代表一个月的一天，如果那天安排了一个或多个事件，则单元格必须为绿色。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();
    }
}

除了设置一个私有字段 eventsByMonth 之外，这个字段还应该填充 datagridview 并为其着色。上面的日历 window 图片是在评论以下代码片段时生成的：

                    //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

鉴于有问题的代码段上方的语句 dgvEventsByMonth.Rows[i].Cells[j].Value = DaysIterator; 从不抛出异常这一事实，问题是什么？

抛出异常时i==3,j==5,DaysIterator==23.

我应该尝试其他方法给单元格着色吗？我不想陷入这个困境。对我来说，做事比解决这类问题更重要。

Answer 1

根据跟踪和堆栈转储，这必须来自 DataGridView 中的索引引用参数。在我们可见的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，所以我推测它是最大行，列索引小于 (3,5 ).

据推测，(mappingOfMonthDaysToEventsByMonth[DaysIterator] != null) 测试并不总是返回正确的结果，而这次失败是因为这是它第一次尝试将背景色设置在其真实范围之外。

Answer 2

您迭代了 dgvEventsByMonth，但在 dgvEventsByDay 中设置了单元格的样式。据我了解，你需要更换它

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

System.ArgumentOutOfRangeException when trying to change the color of a cell in a dataGridView

c#

winforms

exception

datagridview

datagridviewcellstyle