求救：DataGridComboBoxColumn”的声明上缺少 partial 修饰符；存在此类型的其他分部声明。

Question

03的代码，然后用在05上就出现这样的错误了，是因为什么呢？如何修改？
using System.Collections;
using System.ComponentModel;
using System.Drawing;
using System.Windows.Forms;
using System.Data;
using System.Collections.Generic;
using System.Diagnostics;
using System.Text;namespace 进销存管理系统
{
    public class DataGridComboBox : ComboBox
    {
        public DataGridComboBox()
        {
        }
         private void InitializeComponent()
        {        }     }
    public class DataGridComboBoxColumn : DataGridColumnStyle
    {
        private int xMargin = 2;
        private int yMargin = 1;
        private DataGridComboBox Combo;
        private string _DisplayMember;
        private string _ValueMember;        private string OldVal = new string(string.Empty.ToCharArray());
        private bool InEdit = false;        public DataGridComboBoxColumn(DataTable DataSource, int DisplayMember, int ValueMember)
        {
            Combo = new DataGridComboBox();
            Combo.Visible = false;
            Combo.DataSource = DataSource;
            Combo.DisplayMember = DisplayMember;
            Combo.ValueMember = ValueMember;
            Combo.DropDownStyle = ComboBoxStyle.DropDown;
        }
        protected override void Abort(int rowNum)
        {
            throw new System.Exception("The method or operation is not implemented.");
            System.Diagnostics.Debug.WriteLine("Abort()");
            RollBack();
            HideComboBox();
            EndEdit();
        }
        protected override bool Commit(CurrencyManager dataSource, int rowNum)
        {
            HideComboBox();
            if (!InEdit)
            {
                return true;
            }
            try
            {
                object Value = Combo.Text;
                if (NullText.Equals(Value))
                {
                    Value = System.Convert.DBNull;
                }
                SetColumnValueAtRow(dataSource, rowNum, Value);
            }
            catch
            {
                RollBack();
                return false;
            }
            this.EndEdit();
            return true;
        }
        protected override void ConcedeFocus()
        {
            Combo.Visible = false;
        }
        protected override void Edit(CurrencyManager Source, int Rownum, Rectangle Bounds, bool ReadOnly, string InstantText, bool CellIsVisible)
        {
            Combo.Text = string.Empty;
            Rectangle OriginalBounds = Bounds;
            OldVal = Combo.Text;            if (CellIsVisible)
            {
                Bounds.Offset(xMargin, yMargin);
                Bounds.Width -= xMargin * 2;
                Bounds.Height -= yMargin;
                Combo.Bounds = Bounds;
                Combo.Visible = true;
            }
            else
            {
                Combo.Bounds = OriginalBounds;
                Combo.Visible = false;
            }            Combo.SelectedValue = GetText(GetColumnValueAtRow(Source, Rownum));            if (InstantText != null)
            {
                Combo.SelectedValue = InstantText;
            }
            Combo.RightToLeft = this.DataGridTableStyle.DataGrid.RightToLeft;
            if (InstantText == null)
            {
                Combo.SelectAll();
            }
            else
            {
                int End = Combo.Text.Length;
                Combo.Select(End, 0);
            }
            if (Combo.Visible)
            {
                DataGridTableStyle.DataGrid.Invalidate(OriginalBounds);
            }            InEdit = true;
        }
        protected override int GetMinimumHeight()
        {
            return Combo.PreferredHeight + yMargin;
        }
        protected override int GetPreferredHeight(Graphics g, object value)
        {
            System.Diagnostics.Debug.WriteLine("GetPreferredHeight()");
            int NewLinIndex = 0;
            int NewLines = 0;
            string ValueString = this.GetText(value);
            do
            {
                NewLinIndex = ValueString.IndexOf("r\n", NewLinIndex + 1);
                NewLines += 1;
            } while (NewLinIndex != -1);
            return FontHeight * NewLines + yMargin;
        }
        protected override Size GetPreferredSize(Graphics g, object value)
        {
            Size Extents = Size.Ceiling(g.MeasureString(GetText(value), this.DataGridTableStyle.DataGrid.Font));
            Extents.Width += xMargin * 2 + DataGridTableGridLineWidth;
            Extents.Height += yMargin;
            return Extents;
        }
        protected override void Paint(Graphics g, Rectangle bounds, CurrencyManager source, int rowNum)
        {
            Paint(g, bounds, source, rowNum, false);
        }
        protected override void Paint(Graphics g, Rectangle bounds, CurrencyManager source, int rowNum,bool alignToRight)
        {
            string Text=GetText(GetColumnValueAtRow(source,rowNum));
            PaintText(g,bounds,Text,alignToRight);
        }
        protected override void Paint(Graphics g, Rectangle bounds, CurrencyManager source, int rowNum, Brush backBrush, Brush foreBrush, bool alignToRight)
        {
            string Text = GetText(GetColumnValueAtRow(source, rowNum));
            PaintText(g, bounds, Text, backBrush, foreBrush, alignToRight);
        }
        protected override void SetDataGrid(DataGrid value)
        {
            base.SetDataGridInColumn(value);
            if (Combo.Parent != null)
            {
                if (Combo.Parent != null)
                {
                    Combo.Parent.Controls.Remove(Combo);
                }
            }
            if (value != null)
            {
                value.Controls.Add(Combo);
            }
        }
        protected override void UpdateUI(CurrencyManager source, int rowNum, string instantText)
        {
            Combo.Text = GetText(GetColumnValueAtRow(source, rowNum));
            if (instantText != null) 
            {
                Combo.Text = instantText;
            }
        }
        private int DataGridTableGridLineWidth
        {
            get 
            {
                if (this.DataGridTableStyle.GridLineStyle == DataGridLineStyle.Solid)
                {
                    return 1;
                }
                else
                {
                    return 0;
                }
            }
        }
        public void EndEdit()
        {
            InEdit = false;
            Invalidate();
        }
        private string GetText(object Value)
        {
            if (Value == System.DBNull.Value) ;
            {
                return NullText;
            }
            if (Value != null)
            {
                return Value.ToString();
            }
            else
            {
                return string.Empty;
            }
        }
        private void HideComboBox()
        {
            if (Combo.Focused)
            {
                this.DataGridTableStyle.DataGrid.Focus();
            }
            Combo.Visible = false;
        }
        private void RollBack()
        {
            Combo.Text = OldVal;
        }
        private void PaintText(Graphics g, Rectangle Bounds, string Text, bool AlignToRight)
        {
            Brush BackBrush = new SolidBrush(this.DataGridTableStyle.BackColor);
            Brush ForeBrush = new SolidBrush(this.DataGridTableStyle.ForeColor);
            PaintText(g, Bounds, Text, BackBrush, ForeBrush, AlignToRight);
        }
        private void PaintText(Graphics g, Rectangle TextBounds, string Text, Brush BackBrush, Brush ForeBrush, bool AlignToRight)
        {
            Rectangle Rect = TextBounds;
            RectangleF RectF = Rect;
            StringFormat Format = new StringFormat();
            if (AlignToRight)
            {
                Format.FormatFlags = StringFormatFlags.DirectionRightToLeft;
            }
            switch (this.Alignment)
            {
                case HorizontalAlignment.Left:
                    Format.Alignment=StringAlignment.Near;
                    break;
                case HorizontalAlignment.Right:
                    Format.Alignment=StringAlignment.Far;
                    break;
                case HorizontalAlignment.Center:
                    Format.Alignment=StringAlignment.Center;
                    break;
            }
            Format.FormatFlags = Format.FormatFlags;
            Format.FormatFlags = StringFormatFlags.NoWrap;
            g.FillRectangle(BackBrush, Rect);
            Rect.Offset(0, yMargin);
            Rect.Height -= yMargin;
            g.DrawString(Text, this.DataGridTableStyle.DataGrid.Font, ForeBrush, RectF, Format);
            Format.Dispose();
        }
    }
}

Answer 1

其他文件中，有相同命名的类。