C# .net+DevExpress自定义控件（UserControl）之分页控件

1、需求

在开发桌面系统时难免会碰到一些很大的表格，上千行甚至上万行，如果把这些表格全部用GridControl展示出来难免会觉得系统很臃肿，而且会影响系统的效率，所以对表格进行分页就比较重要了。其实在Dev中有自带的所谓“分页控件DataNavigation”，但是那个和我们一般使用的还是有很大区别，dev自带的分页控件准确来说是一个导航控件，显示的还是一张大表。

2、分页控件UI设计

左边是上下页和首末页的label，点击控件触发响应事件，还可以在文本框中输入页码来指定页跳转，还可以设置每页显示的条数。

3、代码实现

3.1属性和私有变量的定义

我定义了绑定的GridControl控件（BindingGrid）、原始表（BindingDataTable）、显示表（ShowingDataTable）和其他用于显示表格信息的属性。这样做有一个问题，如果绑定的表格控件绑定的数据是列表那么就比较麻烦，优化的时候可以在这个点进行优化。

     #region 定义变量private int dataSourceRowsCount;#endregion#region 定义属性/// <summary>/// 绑定的表格控件/// </summary>public GridControl BindingGrid{get; set;}/// <summary>/// 和控件关联的表格/// </summary>public DataTable BindingDataTable{get; set;}/// <summary>/// 显示的表格/// </summary>public DataTable ShowingDataTable{get; set;}/// <summary>/// 总页数/// </summary>public int TotalPages{get; set;}/// <summary>/// 当前页/// </summary>public int CurrentPage{get; set;}/// <summary>/// 每页条数/// </summary>public int RowsCount{get; set;}#endregion

3.2控件初始化

我这里最开始没设计好，需要提供两个参数进行控件初始化，后期可以优化成只提供GridControl参数进行初始化。

     /// <summary>/// 初始化控件显示/// </summary>/// <param name="dataTable"></param>public void InitCtrl(DataTable dataTable, GridControl gridControl){try{#region 初始化属性BindingGrid = gridControl;BindingDataTable = dataTable;RowsCount = Convert.ToInt32(cbxRowCount.Text);dataSourceRowsCount = BindingDataTable.Rows.Count;TotalPages = (int)Math.Ceiling((double)dataSourceRowsCount / RowsCount);CurrentPage = dataSourceRowsCount == 0 ? 0 : 1;ShowingDataTable = new DataTable();if (BindingDataTable.Rows.Count == 0){#region 初始化控件显示tbxCurrentPage.Text = CurrentPage.ToString();lbTotalPages.Text = TotalPages.ToString();lbTotalRows.Text = "共 " + dataSourceRowsCount.ToString() + " 条记录";#endregionreturn;}if (BindingDataTable.Rows.Count > 0 && BindingDataTable.Rows.Count <= RowsCount){ShowingDataTable = BindingDataTable.Copy();}else{DataColumnCollection dataColumns = BindingDataTable.Columns;foreach (DataColumn dataColumn in dataColumns){ShowingDataTable.Columns.Add(dataColumn.ColumnName, dataColumn.DataType);}DataRow dataRow = null;for (int i = 0; i < 20; i++){dataRow = ShowingDataTable.NewRow();int s = ShowingDataTable.Rows.Count;dataRow = BindingDataTable.Rows[i];ShowingDataTable.ImportRow(dataRow);}}#endregion#region 初始化控件显示tbxCurrentPage.Text = CurrentPage.ToString();lbTotalPages.Text = "共 " + TotalPages.ToString() + " 页";lbTotalRows.Text = "共 " + dataSourceRowsCount.ToString() + " 条记录";#endregion}catch (Exception ex){XtraMessageBox.Show("初始化列表失败");//添加日志记录相关方法}finally{BindingGrid.DataSource = ShowingDataTable;BindingGrid.Refresh();}}

3.3 上下页和首末页点击事件

        //点击首页按钮private void lbFirstPage_Click(object sender, EventArgs e){if (CurrentPage == 1)return;CurrentPage = 1;tbxCurrentPage.Text = CurrentPage.ToString();SetShowingDataTable();}//点击上一页按钮private void lbPrePage_Click(object sender, EventArgs e){if (CurrentPage == 1)return;CurrentPage--;tbxCurrentPage.Text = CurrentPage.ToString();SetShowingDataTable();}//点击下一页按钮private void lbNextPage_Click(object sender, EventArgs e){if (CurrentPage == TotalPages)return;CurrentPage++;tbxCurrentPage.Text = CurrentPage.ToString();SetShowingDataTable();}//末页按钮private void lbEnd_Click(object sender, EventArgs e){if (CurrentPage == TotalPages)return;CurrentPage = TotalPages;tbxCurrentPage.Text = CurrentPage.ToString();SetShowingDataTable();}

上面的代码中，SetShowingDataTable()方法用来生成显示的表格：

        /// <summary>/// 根据当前页、显示行数确定显示的表格/// </summary>private void SetShowingDataTable(){try{if (BindingDataTable.Rows.Count <= RowsCount){ShowingDataTable = BindingDataTable.Copy();return;}else{int startRowIndex = (CurrentPage - 1) * RowsCount;int endRoeIndex = startRowIndex + RowsCount;if (endRoeIndex > BindingDataTable.Rows.Count){endRoeIndex = BindingDataTable.Rows.Count;}ShowingDataTable.Rows.Clear();DataRow dataRow = null;for (int i = startRowIndex; i < endRoeIndex; i++){dataRow = ShowingDataTable.NewRow();dataRow = BindingDataTable.Rows[i];ShowingDataTable.ImportRow(dataRow);}}}catch (Exception ex){XtraMessageBox.Show("列表显示失败");//添加日志记录相关方法}finally{BindingGrid.DataSource = ShowingDataTable;BindingGrid.Refresh();}}#endregion

3.4 更改条数和跳转指定页

        //选择每页显示条数private void cbxRowCount_SelectedIndexChanged(object sender, EventArgs e){RowsCount = Convert.ToInt32(cbxRowCount.Text);CurrentPage = 1;TotalPages = (int)Math.Ceiling((double)BindingDataTable.Rows.Count / RowsCount);ShowingDataTable.Rows.Clear();SetShowingDataTable();tbxCurrentPage.Text = CurrentPage.ToString();lbTotalPages.Text = TotalPages.ToString();}//手动输入显示页面编号private void tbxCurrentPage_KeyDown(object sender, KeyEventArgs e){if (e.KeyCode == Keys.Enter){int page = Convert.ToInt32(tbxCurrentPage.Text);if (page < 1){CurrentPage = 1;tbxCurrentPage.Text = "1";}else if (page > TotalPages){CurrentPage = TotalPages;tbxCurrentPage.Text = CurrentPage.ToString();}else{CurrentPage = page;tbxCurrentPage.Text = CurrentPage.ToString();}SetShowingDataTable();}}

3.5 调用自定义分页控件

在控件初始化之后，直接调用InitCtrl()方法进行初始化：

//vs自动生成的代码
private UserControls.Data.CtrlGridNavigation ctrlGridNavigation1;
this.ctrlGridNavigation1 = new UserControls.Data.CtrlGridNavigation();
//ctrlGridNavigation1.InitCtrl(bindingDataTable, bindingGridControl);

4、代码下载

github：github下载
CSDN：CSDN下载