如何使 DataGridView 的宽度和高度适合其内容？

Question

我有一种动态创建 DataGridView 的方法，但是当它显示出来时，宽度大于内容宽度（列的总宽度）。高度也没有足够的长度来满足行的长度。

我尝试使用这种方法，但没有奏效：

    DataGridView CreateInputBox(int proc, int mac)
        {
            DataGridView databox = new DataGridView();
            for (int i = 0; i < mac; i++)
            {
                databox.Columns.Add("col" + (i + 1), "M" + (i + 1));
                databox.Columns[i].DefaultCellStyle.Alignment = DataGridViewContentAlignment.MiddleCenter;
                databox.Columns[i].SortMode = DataGridViewColumnSortMode.NotSortable;
            }
            databox.RowTemplate.DefaultHeaderCellType = typeof(CustomHeaderCell);
            databox.RowHeadersWidthSizeMode = DataGridViewRowHeadersWidthSizeMode.AutoSizeToAllHeaders;
            databox.RowHeadersDefaultCellStyle.Padding = new Padding(2);
            for (int i = 0; i < proc; i++)
            {
                databox.Rows.Add();
                databox.Rows[i].HeaderCell.Value = "P" + (i + 1);
            }
            databox.DefaultCellStyle.SelectionBackColor = Color.LightGray;
            databox.AllowUserToAddRows = false;
            databox.AllowUserToDeleteRows = false;
            databox.AllowUserToOrderColumns = false;
            databox.AutoSizeColumnsMode = DataGridViewAutoSizeColumnsMode.AllCells;
            databox.AutoSizeRowsMode = DataGridViewAutoSizeRowsMode.AllCells;

            //This block doesn't work
            var totalHeight = databox.Rows.GetRowsHeight(DataGridViewElementStates.None);
            var totalWidth = databox.Columns.GetColumnsWidth(DataGridViewElementStates.None);
            databox.Width = totalWidth;
            databox.Height = totalHeight;
            //
            return databox;
        }
    public class CustomHeaderCell : DataGridViewRowHeaderCell
    {
        protected override Size GetPreferredSize(Graphics graphics, DataGridViewCellStyle cellStyle, int rowIndex, Size constraintSize)
        {
            var size1 = base.GetPreferredSize(graphics, cellStyle, rowIndex, constraintSize);
            var value = string.Format("{0}", this.DataGridView.Rows[rowIndex].HeaderCell.FormattedValue);
            var size2 = TextRenderer.MeasureText(value, cellStyle.Font);
            var padding = cellStyle.Padding;
            return new Size(size2.Width + padding.Left + padding.Right, size1.Height);
        }
        protected override void Paint(Graphics graphics, Rectangle clipBounds, Rectangle cellBounds, int rowIndex, DataGridViewElementStates cellState, object value, object formattedValue, string errorText, DataGridViewCellStyle cellStyle, DataGridViewAdvancedBorderStyle advancedBorderStyle, DataGridViewPaintParts paintParts)
        {
            base.Paint(graphics, clipBounds, cellBounds, rowIndex, cellState, value, formattedValue, errorText, cellStyle, advancedBorderStyle, DataGridViewPaintParts.Background);
            base.PaintBorder(graphics, clipBounds, cellBounds, cellStyle, advancedBorderStyle);
            TextRenderer.DrawText(graphics, string.Format("{0}", formattedValue), cellStyle.Font, cellBounds, cellStyle.ForeColor);
        }
    }

结果：

如您所见，DataGridView 控件的宽度如此之长。我怎样才能适应这两个维度？

Answer 1

主要问题是您新创建的DataGridView在添加到父容器之前尚未完成其内部布局，并且仍将报告所有列的宽度为 100。

修复它的一种方法是在显示 DGV后调用大小调整函数：

void sizeDGV(DataGridView dgv)
{
    DataGridViewElementStates states = DataGridViewElementStates.None;
    dgv.ScrollBars = ScrollBars.None;
    var totalHeight = dgv.Rows.GetRowsHeight(states) + dgv.ColumnHeadersHeight;
    totalHeight += dgv.Rows.Count * 4  // a correction I need
    var totalWidth = dgv.Columns.GetColumnsWidth(states) + dgv.RowHeadersWidth;
    dgv.ClientSize = new Size(totalWidth , totalHeight );
}

请注意，我在此过程中修复了一些问题：

• 宽度和高度都不包括标题
• 更改外部尺寸会忽略边框。我改为更改 ClientSize。
• 在大小可以工作之前，我们需要关闭滚动条。