我有一个datagrid,当用户将文件拖放到其上时,该数据网格填充了CSV数据.是否可以在空白网格中显示消息,例如"请在此处拖动文件"或"此网格当前为空".当我等到文件被拖动以设置列等时,网格当前显示为深灰色框.
我们继承了DataGridView控件并添加了它.我们不需要拖放功能 - 我们只需要告诉用户何时没有从查询中返回数据.
我们有一个像这样声明的emptyText属性:
private string cvstrEmptyText = ""; [Category("Custom")] [Description("Displays a message in the DataGridView when no records are displayed in it.")] [DefaultValue(typeof(string), "")] public string EmptyText { get { return this.cvstrEmptyText; } set { this.cvstrEmptyText = value; } }
并重载了PaintBackground函数:
protected override void PaintBackground(Graphics graphics, Rectangle clipBounds, Rectangle gridBounds) { RectangleF ef; base.PaintBackground(graphics, clipBounds, gridBounds); if ((this.Enabled && (this.RowCount == 0)) && (this.EmptyText.Length > 0)) { string emptyText = this.EmptyText; ef = new RectangleF(4f, (float)(this.ColumnHeadersHeight + 4), (float)(this.Width - 8), (float)((this.Height - this.ColumnHeadersHeight) - 8)); graphics.DrawString(emptyText, this.Font, Brushes.LightGray, ef); } }