如何在开头插入新数据网格视图行时删除最后一个数据网格视图行
本文关键字:视图 网格 数据 删除 最后一个 数据网 开头 新数据 插入 | 更新日期: 2023-09-27 18:31:38
使用 Windows 窗体应用程序。
我有这个类,派生自一个DataGridView
控件:
public class CustomDataGridView : DataGridView
{
private int maxRowsAllowed = 3;
public CustomDataGridView()
{
this.AutoGenerateColumns = false;
this.AllowUserToAddRows = false;
this.AllowUserToDeleteRows = false;
this.ReadOnly = true;
this.RowsAdded += CustomDataGridView_RowsAdded;
this.SelectionMode = DataGridViewSelectionMode.FullRowSelect;
}
public void Start()
{
this.Columns.Add("col1", "header1");
this.Columns.Add("col2", "header2");
// rows added manually, no DataSource
this.Rows.Add(maxRowsAllowed);
}
private void customDataGridView_RowsAdded(object sender, DataGridViewRowsAddedEventArgs e)
{
// At this point, while debugging, I realized that CurrentRow is null,
// doing impossible to change it to a previous one, this way avoiding an exception.
if (this.Rows.Count > maxRowsAllowed)
{
this.Rows.RemoveAt(maxRowsAllowed);
}
}
}
然后,从容器类中,在方法AddRowAtBeginning
索引处插入一个新行,将一个索引向下移动其他索引。
引发RowsAdded
事件时,仅当实际总行数大于rowsAllowed
时,才会删除最后一个行数。
public class ContainerForm : Form
{
private CustomDataGridView dgv;
public ContainerForm()
{
InitializeComponent();
dgv = new CustomDataGridView();
dgv.Size = new Size(400, 200);
dgv.Location = new Point(10, 10);
this.Controls.Add(dgv);
dgv.Start();
}
// Inserts a row at 0 index
private void aButton_Click(object sender, EventArgs e)
{
var newRow = new DataGridViewRow();
newRow.DefaultCellStyle.BackColor = Color.LightYellow;
dgv.Rows.Insert(0, newRow);
}
}
一切正常,直到由于位移而选择删除CurrentRow
(标题上有小箭头)。
我想,这就是System.ArgumentOutOfRangeException
被扔的原因,当RowsAdded
逃跑时,试图回到dgv.Rows.Insert(0, newRow)
线。
我还找不到任何解决方案。
尝试更改此设置
if (this.Rows.Count > maxRowsAllowed)
{
this.Rows.RemoveAt(maxRowsAllowed);
}
对此
if (this.Rows.Count > maxRowsAllowed)
{
// if the number of rows is 10
// the index of the last item is 9
// index 10 is out of range
this.Rows.RemoveAt(maxRowsAllowed -1);
}