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DataGridBoolColumn Class

Specifies a column in which each cell contains a check box for representing a Boolean value.

Namespace:  System.Windows.Forms
Assembly:  System.Windows.Forms (in System.Windows.Forms.dll)

public class DataGridBoolColumn : DataGridColumnStyle

The DataGridBoolColumn derives from the abstract class DataGridColumnStyle. At run time, the DataGridBoolColumn contains check boxes in each cell that have three states by default: checked (true), unchecked (false), and Value. To use two-state check boxes, set the AllowNull property to false.

Properties added to the class include FalseValue, NullValue, and TrueValue. These properties specify the value underlying each of the column's states.

The following code example first creates a new DataGridBoolColumn and adds it to the GridColumnStylesCollection of a DataGridTableStyle.

using System;
using System.Data;
using System.Windows.Forms;
using System.Drawing;
using System.ComponentModel;

public class MyForm : Form 
{
    private DataTable myTable;
    private DataGrid myGrid = new DataGrid();

    public MyForm() : base() 
    {
        try
        {
            InitializeComponent();

            myTable = new DataTable("NamesTable");
            myTable.Columns.Add(new DataColumn("Name"));
            DataColumn column = new DataColumn
                ("id", typeof(System.Int32));
            myTable.Columns.Add(column);
            myTable.Columns.Add(new 
                DataColumn("calculatedField", typeof(bool)));
            DataSet namesDataSet = new DataSet();
            namesDataSet.Tables.Add(myTable);
            myGrid.SetDataBinding(namesDataSet, "NamesTable");

            AddTableStyle();
            AddData();
        }
        catch (System.Exception exc)
        {
            Console.WriteLine(exc.ToString());
        }
    }


    private void grid_Enter(object sender, EventArgs e) 
    {
        myGrid.CurrentCell = new DataGridCell(2,2);
    }

    private void AddTableStyle()
    {
        // Map a new  TableStyle to the DataTable. Then  
        // add DataGridColumnStyle objects to the collection 
        // of column styles with appropriate mappings.
        DataGridTableStyle dgt = new DataGridTableStyle();
        dgt.MappingName = "NamesTable";

        DataGridTextBoxColumn dgtbc = new DataGridTextBoxColumn();
        dgtbc.MappingName = "Name";
        dgtbc.HeaderText= "Name";
        dgt.GridColumnStyles.Add(dgtbc);

        dgtbc = new DataGridTextBoxColumn();
        dgtbc.MappingName = "id";
        dgtbc.HeaderText= "id";
        dgt.GridColumnStyles.Add(dgtbc);

        DataGridBoolColumnInherit db = 
            new DataGridBoolColumnInherit();
        db.HeaderText= "less than 1000 = blue";
        db.Width= 150;
        db.MappingName = "calculatedField";
        dgt.GridColumnStyles.Add(db);

        myGrid.TableStyles.Add(dgt);

        // This expression instructs the grid to change 
        // the color of the inherited DataGridBoolColumn 
        // according to the value of the id field. If it's 
        // less than 1000, the row is blue. Otherwise, 
        // the color is yellow.
        db.Expression = "id < 1000";
    }

    private void AddData() 
    {
        // Add data with varying numbers for the id field. 
        // If the number is over 1000, the cell will paint 
        // yellow. Otherwise, it will be blue.
        DataRow dRow = myTable.NewRow();

        dRow["Name"] = "name 1 ";
        dRow["id"] = 999;
        myTable.Rows.Add(dRow);

        dRow = myTable.NewRow();
        dRow["Name"] = "name 2";
        dRow["id"] = 2300;
        myTable.Rows.Add(dRow);

        dRow = myTable.NewRow();
        dRow["Name"] = "name 3";
        dRow["id"] = 120;
        myTable.Rows.Add(dRow);

        dRow = myTable.NewRow();
        dRow["Name"] = "name 4";
        dRow["id"] = 4023;
        myTable.Rows.Add(dRow);

        dRow = myTable.NewRow();
        dRow["Name"] = "name 5";
        dRow["id"] = 2345;
        myTable.Rows.Add(dRow);

        myTable.AcceptChanges();
    }

    private void InitializeComponent() 
    {
        this.Size = new Size(500, 500);
        myGrid.Size = new Size(350, 250);
        myGrid.TabStop = true;
        myGrid.TabIndex = 1;

        this.StartPosition = FormStartPosition.CenterScreen;
        this.Controls.Add(myGrid);
      }
    [STAThread]
    public static void Main() 
    {
        Application.Run(new MyForm());
    }
}

public class DataGridBoolColumnInherit : DataGridBoolColumn 
{
    private SolidBrush trueBrush = Brushes.Blue as SolidBrush;
    private SolidBrush falseBrush = Brushes.Yellow as SolidBrush;
    private DataColumn expressionColumn = null;
    private static int count = 0;

    public Color FalseColor 
    {
        get 
        {
            return falseBrush.Color;
        }
        set 
        {
            falseBrush = new SolidBrush(value);
            Invalidate();
        }
    }

    public Color TrueColor 
    {
        get 
        {
            return trueBrush.Color;
        }
        set 
        {
            trueBrush = new SolidBrush(value);
            Invalidate();
        }
    }

    public DataGridBoolColumnInherit() : base () 
    {
        count ++;
    }


    // This will work only with a DataSet or DataTable. 
    // The code is not compatible with IBindingList implementations. 
    public string Expression 
    {
        get 
        {
            return this.expressionColumn == null ? String.Empty : 
                this.expressionColumn.Expression;
        }
        set 
        {
            if (expressionColumn == null)
                AddExpressionColumn(value);
            else 
                expressionColumn.Expression = value;
            if (expressionColumn != null && 
                expressionColumn.Expression.Equals(value))
                return;
            Invalidate();
        }
    }

    private void AddExpressionColumn(string value) 
    {
        // Get the grid's data source. First check for a null  
        // table or data grid. 
        if (this.DataGridTableStyle == null || 
            this.DataGridTableStyle.DataGrid == null)
            return;

        DataGrid myGrid = this.DataGridTableStyle.DataGrid;
        DataView myDataView = ((CurrencyManager) 
            myGrid.BindingContext[myGrid.DataSource, 
            myGrid.DataMember]).List 
            as DataView;

        // This works only with System.Data.DataTable. 
        if (myDataView == null)
            return;

        // If the user already added a column with the name  
        // then exit. Otherwise, add the column and set the  
        // expression to the value passed to this function.
        DataColumn col = myDataView.Table.Columns["__Computed__Column__"];
        if (col != null)
            return;
        col = new DataColumn("__Computed__Column__" + count.ToString());

        myDataView.Table.Columns.Add(col);
        col.Expression = value;
        expressionColumn = col;
    }

    // override the OnPaint method to paint the cell based on the expression. 
    protected override void Paint(Graphics g, Rectangle bounds,
        CurrencyManager source, int rowNum,
        Brush backBrush, Brush foreBrush,
        bool alignToRight) 
    {
        bool trueExpression = false;
        bool hasExpression = false;
        DataRowView drv = source.List[rowNum] as DataRowView;

        hasExpression = this.expressionColumn != null && 
            this.expressionColumn.Expression != null && 
            !this.expressionColumn.Expression.Equals(String.Empty);

        Console.WriteLine(string.Format("hasExpressionValue {0}",hasExpression));
        // Get the value from the expression column. 
        // For simplicity, we assume a True/False value for the  
        // expression column. 
        if (hasExpression) 
        {
            object expr = drv.Row[expressionColumn.ColumnName];
            trueExpression = expr.Equals("True");
        }

        // Let the DataGridBoolColumn do the painting. 
        if (!hasExpression)
            base.Paint(g, bounds, source, rowNum, 
                backBrush, foreBrush, alignToRight);

        // Paint using the expression color for true or false, as calculated. 
        if (trueExpression)
            base.Paint(g, bounds, source, rowNum, 
                trueBrush, foreBrush, alignToRight);
        else 
            base.Paint(g, bounds, source, rowNum, 
                falseBrush, foreBrush, alignToRight);
    }
}

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

.NET Framework

Supported in: 3.5, 3.0, 2.0, 1.1, 1.0

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