让DataGridView列不可用(转)

单元格可以设置为只读而不可编辑，但DataGridView却没提供使单元格不可用的支持。一般意义上，不可用意味着用户不能进行操作，通常会带有外观的暗示，如灰色。没有一种简单的方法来创建那种不可操作的单元格，但提供一个暗示性的外观告诉用户某单元格不可用还是可行的。内置的单元格类型没有进行不可用设置的属性，下面的例子扩展了DataGridViewButtonCell ，参照常见控件的Enabled属性，为其添加了Enabled属性，如果该属性设置为false，那么其外观状态将类似于普通按钮的不可用状态。

public class DataGridViewDisableButtonColumn : DataGridViewButtonColumn

{

    public DataGridViewDisableButtonColumn()

    {

        this.CellTemplate = new DataGridViewDisableButtonCell();

    }

}

 

public class DataGridViewDisableButtonCell : DataGridViewButtonCell

{

    private bool enabledValue;

    public bool Enabled

    {

        get {

            return enabledValue;

        }

        set {

            enabledValue = value;

        }

    }

 

    // Override the Clone method so that the Enabled property is copied.

    public override object Clone()

{

DataGridViewDisableButtonCell cell =

            (DataGridViewDisableButtonCell)base.Clone();

        cell.Enabled = this.Enabled;

        return cell;

    }

 

    // By default, enable the button cell.

    public DataGridViewDisableButtonCell()

    {

        this.enabledValue = true;

    }

 

    protected override void Paint(Graphics graphics,

        Rectangle clipBounds, Rectangle cellBounds, int rowIndex,

        DataGridViewElementStates elementState, object value,

        object formattedValue, string errorText,

        DataGridViewCellStyle cellStyle,

        DataGridViewAdvancedBorderStyle advancedBorderStyle,

        DataGridViewPaintParts paintParts)

    {

        // The button cell is disabled, so paint the border, 

        // background, and disabled button for the cell.

        if (!this.enabledValue)

        {

            // Draw the cell background, if specified.

            if ((paintParts & DataGridViewPaintParts.Background) ==

                DataGridViewPaintParts.Background)

            {

SolidBrush cellBackground =

                    new SolidBrush(cellStyle.BackColor);

                graphics.FillRectangle(cellBackground, cellBounds);

                cellBackground.Dispose();

            }

 

            // Draw the cell borders, if specified.

            if ((paintParts & DataGridViewPaintParts.Border) ==

                DataGridViewPaintParts.Border)

            {

                PaintBorder(graphics, clipBounds, cellBounds, cellStyle,

                    advancedBorderStyle);

            }

 

            // Calculate the area in which to draw the button.

            Rectangle buttonArea = cellBounds;

            Rectangle buttonAdjustment =

                this.BorderWidths(advancedBorderStyle);

            buttonArea.X += buttonAdjustment.X;

            buttonArea.Y += buttonAdjustment.Y;

            buttonArea.Height -= buttonAdjustment.Height;

            buttonArea.Width -= buttonAdjustment.Width;

 

            // Draw the disabled button.               

            ButtonRenderer.DrawButton(graphics, buttonArea,

                PushButtonState.Disabled);

 

            // Draw the disabled button text.

            if (this.FormattedValue is String)

            {

                TextRenderer.DrawText(graphics,

                    (string)this.FormattedValue,

                    this.DataGridView.Font,

                    buttonArea, SystemColors.GrayText);

            }

        }

        else

        {

            // The button cell is enabled, so let the base class

            // handle the painting.

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

                elementState, value, formattedValue, errorText,

                cellStyle, advancedBorderStyle, paintParts);

        }

    }