DataGridView添加行号.doc

自己在做WINFORM小玩意的时候需要在datagridview上显示行号，上网搜索一下，找到如下代码，不错，先记录下来了。 在RowPostPaint事件中画出来C#代码 1. /绘制行号 2. privatevoidgvdata_RowPostPaint(objectsender,DataGridViewRowPostPaintEventArgse) 3. 4. try 5. 6. 7. Rectanglerectangle=newRectangle(e.RowBounds.Location.X, 8. 9. Convert.ToInt32(e.RowBounds.Location.Y+(e.RowBounds.Height-gvdata.RowHeadersDefaultCellStyle.Font.Size)/2), 10. 11. gvdata.RowHeadersWidth-4,e.RowBounds.Height); 12. 13. TextRenderer.DrawText(e.Graphics,(e.RowIndex+1).ToString(), 14. 15. gvdata.RowHeadersDefaultCellStyle.Font,rectangle,gvdata.RowHeadersDefaultCellStyle.ForeColor, 16. 17. TextFormatFlags.Right); 18. 19. 20. 21. 22. 23. catch(Exceptionex) 24. 25. 26. Console.Write(dgv1_RowPostPaint：+ex.Message); 27. 28. 29. 效果如图：/* #region dataGridView /显示行号 private void dataGridView_RowPostPaint(object sender, DataGridViewRowPostPaintEventArgs e) Rectangle rectangle = new Rectangle(e.RowBounds.Location.X, e.RowBounds.Location.Y, dataGridView.RowHeadersWidth - 8, e.RowBounds.Height); TextRenderer.DrawText(e.Graphics, (e.RowIndex + 1).ToString(), dataGridView.RowHeadersDefaultCellStyle.Font, rectangle, dataGridView.RowHeadersDefaultCellStyle.ForeColor, TextFormatFlags.VerticalCenter | TextFormatFlags.Right); #endregion private void dataGridView_RowPostPaint(object sender, DataGridViewRowPostPaintEventArgs e) try /添加行号 SolidBrush v_SolidBrush = new SolidBrush(dataGridView.RowHeadersDefaultCellStyle.ForeColor); int v_LineNo = 0; v_LineNo = e.RowIndex + 1; string v_Line = v_LineNo.ToString(); e.Graphics.DrawString(v_Line, e.InheritedRowStyle.Font, v_SolidBrush, e.RowBounds.Location.X + 15, e.RowBounds.Location.Y + 5); catch (Exception ex) MessageBox.Show(添加行号时发生错误，错误信息： + ex.Message, 操作失败); */人云亦云，我为DataGridView控件显示行号正名 前些天在写个小程序，用到DataGridView，想给它动态的显示行号。不是很费劲GOOGLE了一下，这GOOGLE不要紧，发现了不少问题。以下基本上都是GOOGLE搜索出来的网上的一些解决方法，千篇一律都是这样的：private void DataGridView1_RowsAdded(object sender, DataGridViewRowsAddedEventArgs e) for (int i = 0; i e.RowCount; i+) this.dgvKBRollUp.Rowse.RowIndex + i.HeaderCell.Style.Alignment = DataGridViewContentAlignment.MiddleRight; this.dgvKBRollUp.Rowse.RowIndex + i.HeaderCell.Value = (e.RowIndex + i + 1).ToString(); for (int i = e.RowIndex + e.RowCount; i this.dgvKBRollUp.Rows.Count; i+) this.dgvKBRollUp.Rowsi.HeaderCell.Style.Alignment = DataGridViewContentAlignment.MiddleRight; this.dgvKBRollUp.Rowsi.HeaderCell.Value = (i + 1).ToString(); private void DataGridView1_RowsRemoved(object sender, DataGridViewRowsRemovedEventArgs e) for (int i = 0; i e.RowCount; i+) this.dgvKBRollUp.Rowse.RowIndex + i.HeaderCell.Style.Alignment = DataGridViewContentAlignment.MiddleRight; this.dgvKBRollUp.Rowse.RowIndex + i.HeaderCell.Value = (e.RowIndex + i + 1).ToString(); for (int i = e.RowIndex + e.RowCount; i this.dgvKBRollUp.Rows.Count; i+) this.dgvKBRollUp.Rowsi.HeaderCell.Style.Alignment = DataGridViewContentAlignment.MiddleRight; this.dgvKBRollUp.Rowsi.HeaderCell.Value = (i + 1).ToString(); 只要用过这段代码的人就应该发现这段代码是运行出错的。原因就出在RowsRemoved事件里，会抛出一个Index outof range的异常。然而就是这么一段有错的代码，几乎充斥着整个互联网，千篇一律的COPY，没有一个人纠正。先说下这段代码出错的原因吧：在RowsRemoved事件里，最开始生成DataGridView的数据的时候，也是会触发这个事件的。这个时候DataGridView控件的Rows.Count就是0。那下面这行代码就有问题了：this.dgvKBRollUp.Rowse.RowIndex + i.HeaderCell.Style.Alignment = DataGridViewContentAlignment.MiddleRight; e.RowIndex + i,这里对应的是Rows0，但是Rows.Count还是0啊，Rows0是不存在的。要存在Rows0起码DataGridView控件要有一行才行。为了避免这个错误，小小的修改代码就行了：private void dgvKBRollUp_RowsRemoved(object sender, DataGridViewRowsRemovedEventArgs e) if (dgvKBRollUp.Rows.Count != 0) for (int i = 0; i e.RowCount; i+) this.dgvKBRollUp.Rowse.RowIndex + i.HeaderCell.Style.Alignment = DataGridViewContentAlignment.MiddleRight; this.dgvKBRollUp.Rowse.RowIndex + i.HeaderCell.Value = (e.RowIndex + i + 1).ToString(); for (int i = e.RowIndex + e.RowCount; i this.dgvKBRollUp.Rows.Count; i+) this.dgvKBRollUp.Rowsi.HeaderCell.Style.Alignment = DataGridViewContentAlignment.MiddleRight; this.dgvKBRollUp.Rowsi.HeaderCell.Value = (i + 1).ToString(); 只要加上一个对Rows.Count的判断就可以避免这个错误。希望网上的一些COPY的朋友也要注意了，以后COPY过来的时候，自己还是要动手验证一下。将一个错误的信息胡乱的传播是对一些新手以及自己都不怎么好的。最后附上微软MSDN里面关于e.RowIndex和e.RowCount的一段代码：System.Text.StringBuilder messageBoxCS = new System.Text.StringBuilder(); messageBoxCS.AppendFormat(0 = 1, RowIndex, e.RowIndex); messageBoxCS.AppendLin