时间:2022-03-09 09:34:59 | 栏目:.NET代码 | 点击:次
由于在使用SQL查询大量的数据并一次显示到dataGridView控件,出现拖拉的时候卡顿。
解决方法:
1.首先分页。
2.其次把显示控件设置双buffer。
1.设置dataGridView双buffer代码如下,需要引用反射命名空间
Type dgvType = this.dataGridView1.GetType(); PropertyInfo pi = dgvType.GetProperty("DoubleBuffered", BindingFlags.Instance | BindingFlags.NonPublic); pi.SetValue(this.dataGridView1, true, null);
2.自己定义分页操作控件,上一页,下一页,首页,尾页,在加载form的时候添加事件。并为他们写一个操作事件
private void Form1_Load(object sender, EventArgs e) { this.btn_EndPage.Click += Ctrl_Click; this.btn_FirstPage.Click += Ctrl_Click; this.btn_LastPage.Click += Ctrl_Click; this.btn_NextPage.Click += Ctrl_Click; //this.SetStyle(ControlStyles.OptimizedDoubleBuffer | ControlStyles.ResizeRedraw | ControlStyles.AllPaintingInWmPaint, true); //this.UpdateStyles(); } private void Ctrl_Click(object sender, EventArgs e) { Button btn = (Button)sender; if (btn.Text == this.btn_EndPage.Text) { if (currentPage == pageCount) { return; } currentPage = pageCount; LoadPage(); } else if (btn.Text == this.btn_FirstPage.Text) { if (currentPage == 1) { return; } currentPage = 1; LoadPage(); } else if (btn.Text == this.btn_LastPage.Text) { if (currentPage == 1) { return; } currentPage--; LoadPage(); } else if (btn.Text == this.btn_NextPage.Text) { if (currentPage == pageCount) { return; } currentPage++; LoadPage(); } else { MessageBox.Show("error"); } }
3.下面代码是分页方法,加载page
#region datagridview sort /// <summary> /// 每页记录数 /// </summary> private int pageSize = 50; /// <summary> /// 总记录数 /// </summary> private int recordCount = 0; /// <summary> /// 总页数 /// </summary> private int pageCount = 0; /// <summary> /// 当前页 /// </summary> private int currentPage = 0; /// <summary> /// 分页的方法 /// </summary> /// <param name="str"></param> private void PageSorter() { foreach (DataColumn col in dt.Columns) { DataGridViewTextBoxColumn dgvc = new DataGridViewTextBoxColumn(); dgvc.Name = ""; dgvc.DataPropertyName = ""; dgvc.HeaderText = col.ToString(); dataGridView1.Columns.Add(dgvc); } recordCount = dt.Rows.Count; //记录总行数 pageCount = (recordCount / pageSize); if ((recordCount % pageSize) > 0) { pageCount++; } //默认第一页 currentPage = 1; LoadPage();//调用加载数据的方法 } /// <summary> /// LoadPage方法 /// </summary> private void LoadPage() { if (currentPage < 1) currentPage = 1; if (currentPage > pageCount) currentPage = pageCount; int beginRecord; //开始指针 int endRecord; //结束指针 DataTable dtTemp; dtTemp = dt.Clone(); beginRecord = pageSize * (currentPage - 1); if (currentPage == 1) beginRecord = 0; endRecord = pageSize * currentPage; if (currentPage == pageCount) endRecord = recordCount; for (int i = beginRecord; i < endRecord; i++) { dtTemp.ImportRow(dt.Rows[i]); } dataGridView1.Rows.Clear(); this.lb_CurrentRow.Text = "当前页: " + currentPage.ToString() + " / " + pageCount.ToString();//当前页 this.lb_TotalRows.Text = "总行数: " + recordCount.ToString() + " 行";//总记录数 把临时table的数据插入到datagridview控件里面。 for (int i = 0; i < dtTemp.Rows.Count; i++) { dataGridView1.Rows.Add(); for (int j = 0; j < dtTemp.Columns.Count; j++) dataGridView1.Rows[i].Cells[j].Value = dtTemp.Rows[i][j].ToString(); } } #endregion
Tips:
文中的“dt”是datatable类型的数据,给位看官可以自己创建,也可以从数据库直接获取测试数据。
1.设置dataGridView自增序列号
//填充序列号 private void dataGridView1_RowPostPaint_1(object sender, DataGridViewRowPostPaintEventArgs e) { Rectangle rectangle = new Rectangle(e.RowBounds.Location.X, e.RowBounds.Location.Y, dataGridView1.RowHeadersWidth - 4, e.RowBounds.Height); TextRenderer.DrawText(e.Graphics, (e.RowIndex + 1).ToString(), dataGridView1.RowHeadersDefaultCellStyle.Font, rectangle, dataGridView1.RowHeadersDefaultCellStyle.ForeColor, TextFormatFlags.VerticalCenter | TextFormatFlags.Right); }
1.设置dataGridView自增序列号
//用委托更新data,防止卡顿。 private delegate void UpdateDataGridView(DataTable dt); private void UpdateGV(DataTable dt) { if (dataGridView1.InvokeRequired) { //这里没有看懂,有大神可以解释下嘛 this.BeginInvoke(new UpdateDataGridView(UpdateGV), new object[] { dt }); } else { dataGridView1.DataSource = dt; dataGridView1.Refresh(); } } }