如何在C#中用弹出窗口来对DataGrid的某一列进行修改

DataGrid是可以绑定ComboBox来进行选择某一列的值，但是有时候选项太多，或者通过一列数据无法完全说明选项含义的时候，就希望来弹出一个窗口，来对子项进行更充分的说明，以供选择。

 

我下面的例子就是说明如何实现一个弹出窗口来对子项进行选择。

首先，继承DataGridTextBoxColumn来定义自己的数据列，具体如下：

public delegate string PopupWindow();

public class DataGridPopupColumn: DataGridTextBoxColumn

{

    private Panel pnlPopup;//Basic control for column

    private System.Windows.Forms.CurrencyManager _source = null;

    private int _rowNum;

    public static int _RowCount = -1;

    PopupWindow PopupWindowHandle;

 

    public DataGridPopupColumn( PopupWindow ShowPopupWindow ) : base()

    {

        // Init class members

        PopupWindowHandle = ShowPopupWindow;

        pnlPopup = new Panel();

 

        // Define event handler

        pnlPopup.Leave += new EventHandler( LeavePanel );

        pnlPopup.Click += new EventHandler( ClickPanel );

        pnlPopup.Paint += new PaintEventHandler( PaintPanel );

    }

 

    private void LeavePanel( object sender, EventArgs e )

    {

        pnlPopup.Hide();//Hide panel

    }

 

    private void ClickPanel( object sender, EventArgs e )

    {

        // Show a window to select value

        object objReturn = this.pnlPopup.Parent.Invoke( PopupWindowHandle );

        if( objReturn != null )

        {

            // Get value from window result

            this.TextBox.Text = objReturn.ToString();

 

            // Save it to data source

            SetColumnValueAtRow( _source, _rowNum, this.TextBox.Text);

 

            // Re-draw panel

            this.pnlPopup.Refresh();

            Invalidate();

        }

    }

 

    private void PaintPanel( object sender, System.Windows.Forms.PaintEventArgs e)

    {

        // Set panel size

        pnlPopup.Width = this.TextBox.Width;

        pnlPopup.Height = this.TextBox.Height;

 

        // Draw back ground same as current cell

        Graphics gPanel = e.Graphics;

        gPanel.FillRectangle( new SolidBrush( this.TextBox.BackColor ),

            0,0, this.pnlPopup.Width, this.pnlPopup.Height );

 

        // Draw text in panel

        StringFormat sfText = new StringFormat();

        sfText.Alignment = StringAlignment.Near;

        sfText.LineAlignment = StringAlignment.Center;

        gPanel.DrawString(

            this.TextBox.Text,

            this.TextBox.Font,

            new SolidBrush( this.TextBox.ForeColor ),

            new Rectangle( new Point( 0, 0 ),

new Size( pnlPopup.Width, pnlPopup.Height ) ),

            sfText );

 

        // Draw a triangle in the right side of panel

        SolidBrush sbBlack = new SolidBrush( Color.Black );

        const float TRI_HEIGHT = 6F;

        PointF[] ptTriangle = new PointF[3]{

             new PointF( pnlPopup.Width - 5 - 12, ( pnlPopup.Height - TRI_HEIGHT ) / 2 ),

             new PointF( pnlPopup.Width - 5 , ( pnlPopup.Height - TRI_HEIGHT ) / 2 ),

             new PointF( pnlPopup.Width - 5 - 6, ( pnlPopup.Height + TRI_HEIGHT ) / 2 )

             };

        gPanel.FillPolygon( sbBlack, ptTriangle );

    }

 

    protected override void Edit( System.Windows.Forms.CurrencyManager source,

        int rowNum, System.Drawing.Rectangle bounds,

        bool readOnly, string instantText, bool cellIsVisible )

    {

        //on very first pass, set this static member to number of items in tables

        if(_RowCount == -1)

            _RowCount =  source.Count;

 

        //check to see if we are on the new row

        if(_RowCount < source.Count)

        {

            // remove the one that has been added

            // and add a new to sync

            source.RemoveAt(source.Count-1);

            source.AddNew();

        }

        _RowCount = source.Count;

           

        base.Edit(source,rowNum, bounds, readOnly, instantText , cellIsVisible);

        _rowNum = rowNum;

        _source = source;

       

        // Init panel

        pnlPopup.Parent = this.TextBox.Parent;

        pnlPopup.Location = this.TextBox.Location;

        pnlPopup.Size = new Size(this.TextBox.Size.Width, this.TextBox.Size.Height);

 

        // Show panel

        pnlPopup.Invalidate();// Modified by Knight on Apr.18, 2006
        pnlPopup.Visible = true;

        pnlPopup.BringToFront();

    }

 

    protected override bool Commit( System.Windows.Forms.CurrencyManager dataSource,

            int rowNum )

    {

        return true;

    }

}

 

       主窗体调用如下。

/// <summary>

/// A method declared for popup-column

/// </summary>

/// <returns></returns>

private string PopupWindow()

{

    frmPopup myPopup = new frmPopup();

    if( myPopup.ShowDialog() == DialogResult.OK )

        return myPopup.SelectedItem;

    else

        return null;

}

 

private void CreateEmployeeTable( out DataTable dtEmployee )

{

    dtEmployee = new DataTable();

    dtEmployee.TableName = "EmployeeInfo";

    //Set data columns

    dtEmployee.Columns.Add( "EmployeeID", typeof( int ) );

    dtEmployee.Columns.Add( "Department", typeof( string ) );

    dtEmployee.Columns.Add( "Name", typeof( string ) );

    dtEmployee.Columns.Add( "Phone", typeof( string ) );

    dtEmployee.Columns.Add( "Address", typeof( string ) );

 

    // Add data

    dtEmployee.Rows.Add( new object[]{ 1, "Sales", "Sales1", "*****","*****" } );

    dtEmployee.Rows.Add( new object[]{ 2, "Sales", "Sales2", "*****","*****" } );

    dtEmployee.Rows.Add( new object[]{ 3, "HR", "HR1", "*****","*****" } );

    dtEmployee.Rows.Add( new object[]{ 4, "HR", "HR2", "*****","*****" } );

    dtEmployee.Rows.Add( new object[]{ 5, "Tech", "Tech1", "*****","*****" } );

    dtEmployee.Rows.Add( new object[]{ 6, "Tech", "Tech2", "*****","*****" } );

    dtEmployee.Rows.Add( new object[]{ 7, "Software", "Software1", "*****","*****" } );

    dtEmployee.Rows.Add( new object[]{ 8, "Software", "Software2", "*****","*****" } );

}

 

private void CreateDataSet()

{

    myDataSet = new DataSet();

    DataTable dtEmployee;

    CreateEmployeeTable( out dtEmployee );

    myDataSet.Tables.Add( dtEmployee );

}

 

private void AddTableStyle()

{

    DataGridTableStyle ts1 = new DataGridTableStyle();

    ts1.MappingName = "EmployeeInfo";

 

    DataGridTextBoxColumn TextCol = new DataGridTextBoxColumn();

    TextCol.MappingName = "EmployeeID";

    TextCol.HeaderText = "Employee ID";

    TextCol.Width = 80;

    ts1.GridColumnStyles.Add(TextCol);

 

    // Add popup column with event method

    DataGridPopupColumn PopupTextCol = new DataGridPopupColumn(

    new PopupWindow( PopupWindow ) );

    PopupTextCol.MappingName = "Department";

    PopupTextCol.HeaderText = "Department";

    PopupTextCol.Width = 100;

    ts1.GridColumnStyles.Add( PopupTextCol );

 

    TextCol = new DataGridTextBoxColumn();

    TextCol.MappingName = "Name";

    TextCol.HeaderText = "Name";

    TextCol.Width = 100;

    ts1.GridColumnStyles.Add(TextCol);

 

    TextCol = new DataGridTextBoxColumn();

    TextCol.MappingName = "Phone";

    TextCol.HeaderText = "Phone";

    TextCol.Width = 100;

    ts1.GridColumnStyles.Add(TextCol);

 

    TextCol = new DataGridTextBoxColumn();

    TextCol.MappingName = "Address";

    TextCol.HeaderText = "Address";

    TextCol.Width = 150;

    ts1.GridColumnStyles.Add(TextCol);

 

    //add the custom table style to the datagrid table styles

    dtgUserInfo.TableStyles.Add(ts1);

}

       

private void BindData()

{

    CreateDataSet();

 

    dtgUserInfo.SetDataBinding( myDataSet, "EmployeeInfo");

           

    AddTableStyle();

}

 

private void frmComboxDB_Load(object sender, System.EventArgs e)

{

    BindData();

}

 

       最后，就是弹出窗口的代码，这部分由于需求不一样，做法可以千变万化，以下只是一个简单的例子，即在一个ListBox进行选择。

public string SelectedItem

{

    get{

        if( lstDepInfo.SelectedItem != null )

            return lstDepInfo.SelectedItem.ToString();

        else

            return null;

    }

}

private void frmPopup_Load(object sender, System.EventArgs e)

{

    lstDepInfo.Items.Add( "Sales" );

    lstDepInfo.Items.Add( "HR" );

    lstDepInfo.Items.Add( "Tech" );

    lstDepInfo.Items.Add( "Software" );

}

 

private void btnOK_Click(object sender, System.EventArgs e)

{

    this.DialogResult = DialogResult.OK;

}

 

private void btnCancel_Click(object sender, System.EventArgs e)

{

    this.DialogResult = DialogResult.Cancel;

}