bindingnavigator上的Delete按钮引发IndexOutOfRangeException

Question

我在winforms应用程序中有一个datagridview，带有一个绑定列表数据源。我正在使用bindingnavigator浏览datagridview中的记录。当我单击bindingnavigator上的Delete按钮时，它会抛出几个带有IndexOutOfRangeException的错误对话框。

当我从RowValidating事件中删除GridView_RowValidating处理程序时，它没有发生，但是我不知道为什么抛出异常。我没有向事件添加任何代码，它只是在bindingsource上调用removeCurrent。

public PersonEditor()
    {
        InitializeComponent();

        isClosing = false;
        wasSaved = true;

        try
        {
            BindingSource source = new BindingSource(DataFetcher.GetPeople(), null);

            gridPeople.DataSource = source;
            bindingNavigator1.BindingSource = source;

            gridPeople.RowValidating += GridView_RowValidating;

            txtRegNr.DataBindings.Add("Text", source, "RegisterNumber", false, DataSourceUpdateMode.OnPropertyChanged);
            txtFirstName.DataBindings.Add("Text", source, "FirstName", false, DataSourceUpdateMode.OnPropertyChanged);
            txtLastName.DataBindings.Add("Text", source, "LastName", false, DataSourceUpdateMode.OnPropertyChanged);
            txtAddress.DataBindings.Add("Text", source, "Address", false, DataSourceUpdateMode.OnPropertyChanged);
            txtCity.DataBindings.Add("Text", source, "City", false, DataSourceUpdateMode.OnPropertyChanged);
            txtPhone.DataBindings.Add("Text", source, "Phone", false, DataSourceUpdateMode.OnPropertyChanged);
            txtZip.DataBindings.Add("Text", source, "ZipCode", false, DataSourceUpdateMode.OnPropertyChanged);
        } -- error handling comes below
    }

    private void GridView_RowValidating(object sender, DataGridViewCellCancelEventArgs e)
    {
        if (!isClosing)
        {
            var sb = new StringBuilder();

            var dg = (DataGridView)sender;

            var cells = dg.Rows[e.RowIndex].Cells;

            if (cells["RegisterNumber"].Value == null)
            {
                if (sb.Length == 0) sb.Append("Following fields cannot be empty:");
                sb.Append(" registerNumber");
            }
            if (cells["FirstName"].Value == null)
            {
                if (sb.Length == 0) sb.Append("Following fields cannot be empty:");
                if (sb.Length > 0) sb.Append(",");
                sb.Append(" FirstName");
            }
            if (cells["LastName"].Value == null)
            {
                if (sb.Length == 0) sb.Append("Following fields cannot be empty:");
                if (sb.Length > 0) sb.Append(",");
                sb.Append(" LastName");
            }
            if (cells["Address"].Value == null)
            {
                if (sb.Length == 0) sb.Append("Following fields cannot be empty:");
                if (sb.Length > 0) sb.Append(",");
                sb.Append(" Address");
            }
            if (cells["ZipCode"].Value == null)
            {
                if (sb.Length == 0) sb.Append("Following fields cannot be empty:");
                if (sb.Length > 0) sb.Append(",");
                sb.Append(" ZipCode");
            }
            if (cells["City"].Value == null)
            {
                if (sb.Length == 0) sb.Append("Following fields cannot be empty:");
                if (sb.Length > 0) sb.Append(",");
                sb.Append(" City");
            }

            if (sb.Length > 0)
            {
                MessageBox.Show(sb.ToString());
                btnSave.Enabled = false;
            }
            else
            {
                btnSave.Enabled = true;
            }
        }
    }