一个多列数据绑定组合框

 

// <ADD>

private List<String> showOnlyColumns = new List<String>();

 

[Description("Set the columns that will be displayed in the dropdown list. If not set, all column will be shown.")]

[Category("Data")]

[DefaultValue(null)]

[Browsable(true)]

[DesignerSerializationVisibility(DesignerSerializationVisibility.Content)]

[Editor("System.Windows.Forms.Design.StringCollectionEditor, System.Design, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a", typeof(System.Drawing.Design.UITypeEditor))]

public List<String> ShowOnlyColumns

{

    get

    {

        return showOnlyColumns;

    }

    set

    {

        showOnlyColumns = value;

    }

}

// </ADD>



// <MODIFY>

private float CalculateTotalWidth()

{

    float totWidth = 0;

 

    for (int colIndex = 0; colIndex < columnWidths.Length; colIndex++)

    {

        // Conditional width calculation

        if (showOnlyColumns.Count == 0 ||

            showOnlyColumns.Contains(columnNames[colIndex]))

        {

            totWidth += (columnWidths[colIndex] + columnPadding);

        }

    }

 

    return totWidth + SystemInformation.VerticalScrollBarWidth;

}

 

protected override void OnDrawItem(DrawItemEventArgs e)

{

    [...]

        // Conditional display

        if (colIndex != valueMemberColumnIndex &&

            (showOnlyColumns.Count == 0 ||

            showOnlyColumns.Contains(columnNames[colIndex])))

        {

            string item = Convert.ToString(FilterItemOnProperty(Items[e.Index], columnNames[colIndex]));

 

            boundsRect.X = lastRight;

            boundsRect.Width = (int)columnWidths[colIndex] + columnPadding;

            lastRight = boundsRect.Right;

 

            //if (colIndex == valueMemberColumnIndex)

            if (colIndex == displayMemberColumnIndex)

            {

                using (Font boldFont = new Font(Font, FontStyle.Bold))

                {

                    e.Graphics.DrawString(item, boldFont, brush, boundsRect);

                }

            }

            else

            {

                e.Graphics.DrawString(item, Font, brush, boundsRect);

            }

 

            if (colIndex < columnNames.Length - 1)

            {

                e.Graphics.DrawLine(linePen, boundsRect.Right, boundsRect.Top, boundsRect.Right, boundsRect.Bottom);

            }

        }

    [...]

    e.DrawFocusRectangle();

}

// </MODIFY>



// <ADD>

protected override void OnCreateControl()

{

    this.SelectedItem = null;

 

    base.OnCreateControl();

}

// </ADD>

 

multiColumnComboBox1.DataSource = _entityContext.CUSTOMER;

multiColumnComboBox1.DisplayMember = "TI_NAME";

 

// In code

multiColumnComboBox1.ShowOnlyColumns.Add("TI_NAME");

multiColumnComboBox1.ShowOnlyColumns.Add("TI_FORNAME");

 

// Or use Visual Studio String Collection Editor

    [ToolboxItem(true)]

    [ToolboxBitmap(typeof(ComboBox))]

    public class MultiColumnComboBox : ComboBox

    {

        private List<String> _showOnlyColumns = new List<String>();

 

        public MultiColumnComboBox()

        {

            DrawMode = DrawMode.OwnerDrawVariable;

        }

 

        public new DrawMode DrawMode

        {

            get { return base.DrawMode; }

            set

            {

                if (value != DrawMode.OwnerDrawVariable)

                {

                    throw new NotSupportedException("Needs to be DrawMode.OwnerDrawVariable");

                }

                base.DrawMode = value;

            }

        }

 

        public new ComboBoxStyle DropDownStyle

        {

            get { return base.DropDownStyle; }

            set

            {

                if (value == ComboBoxStyle.Simple)

                {

                    throw new NotSupportedException("ComboBoxStyle.Simple not supported");

                }

                base.DropDownStyle = value;

            }

        }

 

        [Description("Set the columns that will be displayed in dropdown list. If not set, every columns will be shown.")]

        [Category("Data")]

        [DefaultValue(null)]

        [Browsable(true)]

        [DesignerSerializationVisibility(DesignerSerializationVisibility.Content)]

        [Editor("System.Windows.Forms.Design.StringCollectionEditor, System.Design, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a", typeof(System.Drawing.Design.UITypeEditor))]

        public List<String> ShowOnlyColumns

        {

            get { return _showOnlyColumns; }

            set { _showOnlyColumns = value; }

        }

 

        protected override void OnDataSourceChanged(EventArgs e)

        {

            base.OnDataSourceChanged(e);

 

            InitializeColumns();

        }

 

        protected override void OnValueMemberChanged(EventArgs e)

        {

            base.OnValueMemberChanged(e);

 

            InitializeValueMemberColumn();

        }

 

        protected override void OnDisplayMemberChanged(EventArgs e)

        {

            base.OnDisplayMemberChanged(e);

 

            InitializeDisplayMemberColumn();

        }

 

        protected override void OnDropDown(EventArgs e)

        {

            base.OnDropDown(e);

 

            this.DropDownWidth = (int)CalculateTotalWidth();

        }

 

        const int columnPadding = 5;

        private float[] columnWidths = new float[0];

        private String[] columnNames = new String[0];

        private int valueMemberColumnIndex = 0;

        private int displayMemberColumnIndex = 0;

 

        private void InitializeColumns()

        {

            PropertyDescriptorCollection propertyDescriptorCollection = DataManager.GetItemProperties();

 

            columnWidths = new float[propertyDescriptorCollection.Count];

            columnNames = new String[propertyDescriptorCollection.Count];

 

            for (int colIndex = 0; colIndex < propertyDescriptorCollection.Count; colIndex++)

            {

                String name = propertyDescriptorCollection[colIndex].Name;

                columnNames[colIndex] = name;

            }

        }

 

        private void InitializeValueMemberColumn()

        {

            int colIndex = 0;

            foreach (String columnName in columnNames)

            {

                if (String.Compare(columnName, ValueMember, true, CultureInfo.CurrentUICulture) == 0)

                {

                    valueMemberColumnIndex = colIndex;

                    columnWidths[colIndex] = 0;

                    break;

                }

                colIndex++;

            }

        }

 

        private void InitializeDisplayMemberColumn()

        {

            int colIndex = 0;

            foreach (String columnName in columnNames)

            {

                if (String.Compare(columnName, DisplayMember, true, CultureInfo.CurrentUICulture) == 0)

                {

                    displayMemberColumnIndex = colIndex;

                    break;

                }

                colIndex++;

            }

        }

 

        private float CalculateTotalWidth()

        {

            float totWidth = 0;

 

            for (int colIndex = 0; colIndex < columnWidths.Length; colIndex++)

            {

                if (_showOnlyColumns.Count == 0 ||

                    _showOnlyColumns.Contains(columnNames[colIndex]))

                {

                    totWidth += (columnWidths[colIndex] + columnPadding);

                }

            }

 

            return totWidth + SystemInformation.VerticalScrollBarWidth;

        }

 

        protected override void OnMeasureItem(MeasureItemEventArgs e)

        {

            base.OnMeasureItem(e);

 

            if (DesignMode)

                return;

 

            for (int colIndex = 0; colIndex < columnNames.Length; colIndex++)

            {

                string item = Convert.ToString(FilterItemOnProperty(Items[e.Index], columnNames[colIndex]));

                SizeF sizeF = e.Graphics.MeasureString(item, Font);

                columnWidths[colIndex] = Math.Max(columnWidths[colIndex], sizeF.Width);

            }

 

            float totWidth = CalculateTotalWidth();

 

            e.ItemWidth = (int)totWidth;

        }

 

        protected override void OnDrawItem(DrawItemEventArgs e)

        {

            base.OnDrawItem(e);

 

            if (DesignMode)

                return;

 

            e.DrawBackground();

 

            Rectangle boundsRect = e.Bounds;

            int lastRight = 0;

 

            using (Pen linePen = new Pen(SystemColors.GrayText))

            {

                using (SolidBrush brush = new SolidBrush(ForeColor))

                {

                    if (columnNames.Length == 0)

                    {

                        e.Graphics.DrawString(Convert.ToString(Items[e.Index]), Font, brush, boundsRect);

                    }

                    else

                    {

                        for (int colIndex = 0; colIndex < columnNames.Length; colIndex++)

                        {

                            if (colIndex != valueMemberColumnIndex &&

                                (_showOnlyColumns.Count == 0 ||

                                _showOnlyColumns.Contains(columnNames[colIndex])))

                            {

                                string item = Convert.ToString(FilterItemOnProperty(Items[e.Index], columnNames[colIndex]));

 

                                boundsRect.X = lastRight;

                                boundsRect.Width = (int)columnWidths[colIndex] + columnPadding;

                                lastRight = boundsRect.Right;

 

                                if (colIndex == displayMemberColumnIndex)

                                {

                                    using (Font boldFont = new Font(Font, FontStyle.Bold))

                                    {

                                        e.Graphics.DrawString(item, boldFont, brush, boundsRect);

                                    }

                                }

                                else

                                {

                                    e.Graphics.DrawString(item, Font, brush, boundsRect);

                                }

 

                                if (colIndex < columnNames.Length - 1)

                                {

                                    e.Graphics.DrawLine(linePen, boundsRect.Right, boundsRect.Top, boundsRect.Right, boundsRect.Bottom);

                                }

                            }

                        }

                    }

                }

            }

 

            e.DrawFocusRectangle();

        }

 

        protected override void OnCreateControl()

        {

            this.SelectedItem = null;

 

            base.OnCreateControl();

        }

    }

var k4 = from p in ctx.vtblCustomerDivisions where p.vtblCustomers.active == true orderby p.vtblCustomers.name select new { p.vtblCustomers.name, p.cd, p.vtblCustomers.custId, p.division, p.address, p.city };

cboCustomerDivCd.DataSource = k4;

cboCustomerDivCd.DisplayMember = "custId";

cboCustomerDivCd.ValueMember = "cd";

cboCustomerDivCd.SelectedIndex = -1;

cboCustomerDivCd.Text = "";

cboCustomerDivCd.BackColorOdd = rowColor;

cboCustomerDivCd.ColumnWidths = "0;0;100;100;100;100";