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  • 如何:禁用 Windows 窗体 DataGridView 控件的按钮列中的按钮

    转自:https://msdn.microsoft.com/zh-cn/library/ms171619(v=vs.110).aspx

    DataGridView 控件包括 DataGridViewButtonCell 类,其用于显示具有与按钮类似的用户界面 (UI) 的单元格。 但是,DataGridViewButtonCell 不提供禁用单元格所显示按钮外观的方法。

    以下代码示例演示如何自定义 DataGridViewButtonCell 类以显示可以显示为禁用的按钮。 此示例定义了一个新的单元格类型,即从 DataGridViewButtonCell 派生的 DataGridViewDisableButtonCell。 此单元格类型提供了一种新 Enabled 属性,可设置为 false 以拖动单元格中已禁用的按钮。 此示例还定义了一个新的列类型,即显示 DataGridViewDisableButtonCell 对象的DataGridViewDisableButtonColumn。 为了演示此新单元格和列类型,父级 DataGridView 中的每个DataGridViewCheckBoxCell 的当前值确定了相同行中 DataGridViewDisableButtonCell 的 Enabled 属性是否是 true 或false

    System_CAPS_note注意

    当从 DataGridViewCell 或 DataGridViewColumn 进行派生并将新属性添加到派生的类时,请确保重写 Clone 方法以在克隆操作过程中复制新属性。 还应调用基类的 Clone 方法,以便将基类的属性复制到新的单元格或列。

    示例

     
    using System;
    using System.Drawing;
    using System.Windows.Forms;
    using System.Windows.Forms.VisualStyles;
    
    class Form1 : Form
    {
        private DataGridView dataGridView1 = new DataGridView();
    
        [STAThread]
        public static void Main()
        {
            Application.EnableVisualStyles();
            Application.Run(new Form1());
        }
    
        public Form1()
        {
            this.AutoSize = true;
            this.Load += new EventHandler(Form1_Load);
        }
    
        public void Form1_Load(object sender, EventArgs e)
        {
            DataGridViewCheckBoxColumn column0 =
                new DataGridViewCheckBoxColumn();
            DataGridViewDisableButtonColumn column1 =
                new DataGridViewDisableButtonColumn();
            column0.Name = "CheckBoxes";
            column1.Name = "Buttons";
            dataGridView1.Columns.Add(column0);
            dataGridView1.Columns.Add(column1);
            dataGridView1.RowCount = 8;
            dataGridView1.AutoSize = true;
            dataGridView1.AllowUserToAddRows = false;
            dataGridView1.ColumnHeadersDefaultCellStyle.Alignment =
                DataGridViewContentAlignment.MiddleCenter;
    
            // Set the text for each button.
            for (int i = 0; i < dataGridView1.RowCount; i++)
            {
                dataGridView1.Rows[i].Cells["Buttons"].Value =
                    "Button " + i.ToString();
            }
    
            dataGridView1.CellValueChanged +=
                new DataGridViewCellEventHandler(dataGridView1_CellValueChanged);
            dataGridView1.CurrentCellDirtyStateChanged +=
                new EventHandler(dataGridView1_CurrentCellDirtyStateChanged);
            dataGridView1.CellClick +=
                new DataGridViewCellEventHandler(dataGridView1_CellClick);
    
            this.Controls.Add(dataGridView1);
        }
    
        // This event handler manually raises the CellValueChanged event
        // by calling the CommitEdit method.
        void dataGridView1_CurrentCellDirtyStateChanged(object sender,
            EventArgs e)
        {
            if (dataGridView1.IsCurrentCellDirty)
            {
                dataGridView1.CommitEdit(DataGridViewDataErrorContexts.Commit);
            }
        }
    
        // If a check box cell is clicked, this event handler disables  
        // or enables the button in the same row as the clicked cell.
        public void dataGridView1_CellValueChanged(object sender,
            DataGridViewCellEventArgs e)
        {
            if (dataGridView1.Columns[e.ColumnIndex].Name == "CheckBoxes")
            {
                DataGridViewDisableButtonCell buttonCell =
                    (DataGridViewDisableButtonCell)dataGridView1.
                    Rows[e.RowIndex].Cells["Buttons"];
    
                DataGridViewCheckBoxCell checkCell =
                    (DataGridViewCheckBoxCell)dataGridView1.
                    Rows[e.RowIndex].Cells["CheckBoxes"];
                buttonCell.Enabled = !(Boolean)checkCell.Value;
    
                dataGridView1.Invalidate();
            }
        }
    
        // If the user clicks on an enabled button cell, this event handler  
        // reports that the button is enabled.
        void dataGridView1_CellClick(object sender,
            DataGridViewCellEventArgs e)
        {
            if (dataGridView1.Columns[e.ColumnIndex].Name == "Buttons")
            {
                DataGridViewDisableButtonCell buttonCell =
                    (DataGridViewDisableButtonCell)dataGridView1.
                    Rows[e.RowIndex].Cells["Buttons"];
    
                if (buttonCell.Enabled)
                {
                    MessageBox.Show(dataGridView1.Rows[e.RowIndex].
                        Cells[e.ColumnIndex].Value.ToString() +
                        " is enabled");
                }
            }
        }
    }
    
    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);
            }
        }
    }
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  • 原文地址:https://www.cnblogs.com/leiliu-lucifer/p/5823188.html
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