using System;

using System.Drawing;

using System.Windows.Forms;



//定义触发单击事件的委托

public delegate void datagridviewcheckboxHeaderEventHander(object sender, datagridviewCheckboxHeaderEventArgs e);



/// <summary>

/// 定义包含列头checkbox选择状态的参数类

/// </summary>

class datagridviewCheckboxHeaderEventArgs : EventArgs

{

    private bool checkedState = false;



    public bool CheckedState

    {

        get { return checkedState; }

        set { checkedState = value; }

    }

}



/// <summary>

/// 定义继承于DataGridViewColumnHeaderCell的类，用于绘制checkbox，定义checkbox鼠标单击事件

/// </summary>

class datagridviewCheckboxHeaderCell : DataGridViewColumnHeaderCell

{

    Point checkBoxLocation;

    Size checkBoxSize;

    bool _checked = false;

    Point _cellLocation = new Point();

    System.Windows.Forms.VisualStyles.CheckBoxState _cbState =

        System.Windows.Forms.VisualStyles.CheckBoxState.UncheckedNormal;

    public event datagridviewcheckboxHeaderEventHander OnCheckBoxClicked;



    //绘制列头checkbox

    protected override void Paint(System.Drawing.Graphics graphics,

      System.Drawing.Rectangle clipBounds,

      System.Drawing.Rectangle cellBounds,

     int rowIndex,

     DataGridViewElementStates dataGridViewElementState,

       object value,

      object formattedValue,

       string errorText,

       DataGridViewCellStyle cellStyle,

       DataGridViewAdvancedBorderStyle advancedBorderStyle,

      DataGridViewPaintParts paintParts)

    {

        base.Paint(graphics, clipBounds, cellBounds, rowIndex,

            dataGridViewElementState, value,

           formattedValue, errorText, cellStyle,

          advancedBorderStyle, paintParts);

        Point p = new Point();

        Size s = CheckBoxRenderer.GetGlyphSize(graphics,

       System.Windows.Forms.VisualStyles.CheckBoxState.UncheckedNormal);

        p.X = cellBounds.Location.X +

           (cellBounds.Width / 2) - (s.Width / 2) - 1;//列头checkbox的X坐标

        p.Y = cellBounds.Location.Y +

            (cellBounds.Height / 2) - (s.Height / 2);//列头checkbox的Y坐标

        _cellLocation = cellBounds.Location;

        checkBoxLocation = p;

        checkBoxSize = s;

        if (_checked)

            _cbState = System.Windows.Forms.VisualStyles.

                 CheckBoxState.CheckedNormal;

        else

            _cbState = System.Windows.Forms.VisualStyles.

                CheckBoxState.UncheckedNormal;

        CheckBoxRenderer.DrawCheckBox

       (graphics, checkBoxLocation, _cbState);

    }



    /// <summary>

    /// 点击列头checkbox单击事件

    /// </summary>

    protected override void OnMouseClick(DataGridViewCellMouseEventArgs e)

    {

        Point p = new Point(e.X + _cellLocation.X, e.Y + _cellLocation.Y);

        if (p.X >= checkBoxLocation.X && p.X <=

            checkBoxLocation.X + checkBoxSize.Width

         && p.Y >= checkBoxLocation.Y && p.Y <=

             checkBoxLocation.Y + checkBoxSize.Height)

        {

            _checked = !_checked;





            //获取列头checkbox的选择状态

            datagridviewCheckboxHeaderEventArgs ex = new datagridviewCheckboxHeaderEventArgs();

            ex.CheckedState = _checked;



            object sender = new object();//此处不代表选择的列头checkbox，只是作为参数传递。应该列头checkbox是绘制出来的，无法获得它的实例



            if (OnCheckBoxClicked != null)

            {

                OnCheckBoxClicked(sender, ex);//触发单击事件

                this.DataGridView.InvalidateCell(this);

            }

        }

        base.OnMouseClick(e);

    }

}

datagridviewCheckboxHeaderCell ch = new datagridviewCheckboxHeaderCell();

//ch.OnCheckBoxClicked += new datagridviewcheckboxHeaderEventHander(ch_OnCheckBoxClicked);//关联单击事件

//假设第三列为DataGridViewCheckBoxColumn

DataGridViewCheckBoxColumn checkboxCol = this.dataGridView1.Columns[2] as DataGridViewCheckBoxColumn;

checkboxCol.HeaderCell = ch;

checkboxCol.HeaderCell.Value = string.Empty;//消除列头checkbox旁出现的文字