[Winform] DataGridView(FAQ)
[Winform] DataGridView(FAQ)Q1. 如何使单元格不可编辑？ A：设置ReadOnly属性，可以设置的对象包括DataGridViewRow（行）、DataGridViewColumn（列）、DataGridViewCell（单元格）以及自身DataGridView对象均可设置ReadOnly属性来限制单元格的编辑状态。
扩展：需要注意的是，当DataGridView通过DataSource绑定数据自动生成行列时，如果直接在Form的构造函数初始化界面InitializeComponent后直接设置ReadOnly属性，会造成一些意想不到的效果……
1 public MainForm() 2 { 3 InitializeComponent() 4 5 application.DoEvents() 6 dataGridView.DataSource = Person.GetPersons() 7 dataGridView[0, 0].ReadOnly = true 8 dataGridView.Rows[2].ReadOnly = true 9 dataGridView.Columns[1].ReadOnly = true 10 }
此时对DataGridViewCell、DataGridViewRow的ReadOnly设置无效，而对DataGridViewColumn的ReadOnly设置有效。
另外，ReadOnly属性只是限制用户在界面上对单元格内容编辑的限制，并不影响在编程代码中对该单元格的编辑以及删除行列操作。
当然，你也可以在CellBeginEdit事件中对单元格进行判断，然后直接结束编辑即可，如下：
1 dataGridView.CellBeginEdit += (sender, e) => 2 { 3 if (e.RowIndex == 0 && e.ColumnIndex == 0) 4 { 5 e.Cancel = true 6 // 或者 7 // dataGridView.EndEdit(); 8 } 9 }
Q2. 如何禁用单元格（Disable）？A：DataGridView不支持设置单元格的不可用状态，所以采用折中办法，使该“禁用”单元格的选中状态和其背景颜色相同，给人暗示性的外观提示该单元格“禁用”。
有一种便捷的方式，就是将该“禁用”单元格的选中颜色设置成非选中颜色，即如果未选中前是白底黑字，则将该“禁用”单元格的选中状态也改成白底黑字即可，对单元格、行和列均适用，举例如下：
1 dataGridView[2, 2].Style.SelectionBackColor = Color.White 2 dataGridView[2, 2].Style.SelectionForeColor = Color.Black 3 4 dataGridView.Rows[1].DefaultCellStyle.SelectionBackColor = Color.White 5 dataGridView.Rows[1].DefaultCellStyle.SelectionForeColor = Color.Black 6 7 dataGridView.Columns[0].DefaultCellStyle.SelectionBackColor = Color.White 8 dataGridView.Columns[0].DefaultCellStyle.SelectionForeColor = Color.Black
需要注意的是，同Q1中一样，在InitializeComponent方法后面直接操作，其中对单元格的设置无效，对行、列的设置有效！！
但是这种方法对文本内容的单元有效，对于DataGridViewButtonColumn、DataGridViewCheckBoxColumn、DataGridViewComboBoxColumn等其他特殊列就没效果了，毕竟对于特殊列，禁用单元格就是要禁用其中的特殊控件，这时候就需要重写其中的单元格模版了，以DataGridViewButtonColumn为例，代码如下：
public class DataGridViewButtonColumnExt : DataGridViewButtonColum{ public DataGridViewButtonColumnExt() { this.CellTemplate = new DataGridViewButtonCellExt() }}public class DataGridViewButtonCellExt : DataGridViewButtonCell{ PRivate bool _Enabled;// 设置该单元格是否可用 /// <summary> /// 单元格是否可用 /// </summary> public bool Enabled { get { return _Enabled } set { _Enabled = value } } public override object Clone() { DataGridViewButtonCellExt cell =(DataGridViewButtonCellExt)base.Clone() cell.Enabled = this.Enabled return cell } public DataGridViewButtonCellExt() { this._Enabled = 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) { if (!this._Enabled) { // 绘制背景 if ((paintParts & DataGridViewPaintParts.Background) == DataGridViewPaintParts.Background) { SolidBrush cellBackground = new SolidBrush(cellStyle.BackColor) graphics.FillRectangle(cellBackground, cellBounds) cellBackground.Dispose() } // 绘制边框 if ((paintParts & DataGridViewPaintParts.Border) == DataGridViewPaintParts.Border) { PaintBorder(graphics, clipBounds, cellBounds, cellStyle, advancedBorderStyle) } Rectangle buttonArea = cellBound Rectangle buttonAdjustment = this.BorderWidths(advancedBorderStyle) buttonArea.X += buttonAdjustment.X buttonArea.Y += buttonAdjustment.Y buttonArea.Height -= buttonAdjustment.Height buttonArea.Width -= buttonAdjustment.Width // 绘制按钮控件 ButtonRenderer.DrawButton(graphics, buttonArea, PushButtonState.Disabled) // 绘制文本内容 if (this.FormattedValue is String) { TextRenderer.DrawText(graphics, (string)this.FormattedValue, this.DataGridView.Font, buttonArea, SystemColors.GrayText) } } else { base.Paint(graphics, clipBounds, cellBounds, rowIndex, elementState, value, formattedValue, errorText, cellStyle, advancedBorderStyle, paintParts) } }}
View Code下面是CheckBox列的重写例子，因为复选框有两种禁用效果，一种选中时禁用，一种是未选中时禁用，所以加了一个IsChecked属性：
public class DataGridViewCheckBoxColumnExt : DataGridViewCheckBoxColum{public DataGridViewCheckBoxColumnExt(){this.CellTemplate = new DataGridViewCheckBoxCellExt()}}public class DataGridViewCheckBoxCellExt : DataGridViewCheckBoxCell{private bool _Enableprivate bool _IsChecked/// <summary>/// 是否选中/// </summary>public bool IsChecked{get{return _IsChecked}set{_IsChecked = value}}/// <summary>/// 是否可用/// </summary>public bool Enable{get{return _Enable}set{_Enable = value}}public DataGridViewCheckBoxCellExt(){_Enable = true_IsChecked = false}public override object Clone(){DataGridViewCheckBoxCellExt dgvcce = (DataGridViewCheckBoxCellExt)base.Clone()dgvcce.Enable = this.Enabledgvcce.IsChecked = this.IsCheckedreturn dgvcce}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){if (!_Enable){// 绘制背景if ((paintParts & DataGridViewPaintParts.Background) == DataGridViewPaintParts.Background){SolidBrush cellBackground = new SolidBrush(cellStyle.BackColor)graphics.FillRectangle(cellBackground, cellBounds)cellBackground.Dispose()}// 绘制边框if ((paintParts & DataGridViewPaintParts.Border) == DataGridViewPaintParts.Border){PaintBorder(graphics, clipBounds, cellBounds, cellStyle, advancedBorderStyle)}Point pos = cellBounds.Locatio// 调整位置居中pos.X = pos.X + cellBounds.Width / 2 - 7pos.Y = pos.Y + cellBounds.Height / 2 - 7// 绘制按钮控件CheckBoxRenderer.DrawCheckBox(graphics, pos,IsChecked ? CheckBoxState.CheckedDisabled : CheckBoxState.UncheckedDisabled)}else{base.Paint(graphics, clipBounds, cellBounds, rowIndex, elementState, value,formattedValue, errorText, cellStyle, advancedBorderStyle, paintParts)}}}
View CodeQ3. 如何在单元格内同时显示图片和文字？A：参考网上查到的资料，将文本列（DataGridViewTextBoxColum）中的文本向右偏移，然后在前面置入图片；
public class TextAndImageColumn : DataGridViewTextBoxColum{ private Image m_ImageValue private Size m_ImageSize public
