C# 解决datagridview控件显示大量数据拖拉卡顿问题

Z时代
2024-01-10
分类：综合

问题描述：

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。

解决过程如下：

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。

Extension1：

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);
    }

Extension2：

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();
      }
    }
    }