【WPF】将DataGrid内容导出到Excel

引言

在完成将DataGrid的内容导出到Excel的时候，参考了一个印度小伙的文章http://www.codeproject.com/Articles/120480/Export-to-Excel-Functionality-in-WPF-DataGrid，很清晰，结合着自己的实际项目写了这篇文章，分享给大家。

步骤

一：创建窗体，绘制datagrid

这里不多讲，直接拖控件就行。

二：为datagrid绑定数据

这里查询结果返回的是泛型，

在XAML文件中需要绑定数据：

<DataGrid x:Name="dgtOnlineRecord" Grid.ColumnSpan="4" Grid.Column="1" HorizontalAlignment="Left" Height="432.842" Grid.Row="4" VerticalAlignment="Top" Width="703.722"
                        ItemsSource="{Binding}" AutoGenerateColumns="False">
                <DataGrid.Columns>
                    <DataGridTextColumn Header="卡号" Binding="{Binding cardID}"/>
                    <DataGridTextColumn Header="上机时间" Binding="{Binding onLineDateTime}"/>
                    <DataGridTextColumn Header="下机时间" Binding="{Binding offLineDateTime}"/>
                    <DataGridTextColumn Header="消费金额" Binding="{Binding costCash}"/>
                    <DataGridTextColumn Header="上机机器" Binding="{Binding onLineComputer}"/>
                DataGrid.Columns>
            DataGrid>

后台代码：

JFFacade.CardManagerFacade cardmanagerfacade = new JFFacade.CardManagerFacade();
//实例化外观层的CardManagerFacade类
dgtOnlineRecord.ItemsSource = cardmanagerfacade.QueryStuOnlineRecord(combinedquery);
//使用QueryStuOnlineRecord（查询学生上机记录）方法，并将返回值赋给datagrid的ItemSource

效果如下所示：

---

三：Excel文件生成类

这里把它封装成了一个类，方便复用，放到了Common层

#region ExportToExcel 导出为Excel
    /// 

    /// 导出Excel类
    /// 
    /// 
    /// 
    public class ExportToExcel
        where T : class
        where U : List
    {
        public List DataToPrint;
        // Excel 对象实例.
        private Excel.Application _excelApp = null;
        private Excel.Workbooks _books = null;
        private Excel._Workbook _book = null;
        private Excel.Sheets _sheets = null;
        private Excel._Worksheet _sheet = null;
        private Excel.Range _range = null;
        private Excel.Font _font = null;

        // 可选 参数
        private object _optionalValue = Missing.Value;
        /// 

        /// 生成报表，和其他功能
        /// 
        /// 
        public int GenerateReport()
        {
            int result = 1;
            try
            {
                if (DataToPrint != null)
                {
                    if (DataToPrint.Count != 0)
                    {
                        CreateExcelRef();
                        FillSheet();
                        OpenReport();
                    }
                }
            }
            catch (Exception e)
            {
                result = 0;
                //("Excel导出失敗！\n", e.Message);
            }
            finally
            {
                ReleaseObject(_sheet);
                ReleaseObject(_sheets);
                ReleaseObject(_book);
                ReleaseObject(_books);
                ReleaseObject(_excelApp);
            }
            return result;
        }
        /// 

        /// 展示 Excel 程序
        /// 
        private void OpenReport()
        {
            _excelApp.Visible = true;
        }
        /// 

        /// 填充 Excel sheet
        /// 
        private void FillSheet()
        {
            object[] header = CreateHeader();
            WriteData(header);
        }
        /// 

        /// 将数据写入 Excel sheet
        /// 
        /// 
        private void WriteData(object[] header)
        {
            object[,] objData = new object[DataToPrint.Count, header.Length];

            for (int j = 0; j < DataToPrint.Count; j++)
            {
                var item = DataToPrint[j];
                for (int i = 0; i < header.Length; i++)
                {
                    var y = typeof(T).InvokeMember(header[i].ToString(),
                    BindingFlags.GetProperty, null, item, null);
                    objData[j, i] = (y == null) ? "" : y.ToString();
                }
            }
            AddExcelRows("A2", DataToPrint.Count, header.Length, objData);
            AutoFitColumns("A1", DataToPrint.Count + 1, header.Length);
        }
        /// 

        /// 根据数据拟合 列
        /// 
        /// 
        /// 
        /// 
        private void AutoFitColumns(string startRange, int rowCount, int colCount)
        {
            _range = _sheet.get_Range(startRange, _optionalValue);
            _range = _range.get_Resize(rowCount, colCount);
            _range.Columns.AutoFit();
        }
        /// 

        /// 根据属性名创建列标题
        /// 
        /// 
        private object[] CreateHeader()
        {
            PropertyInfo[] headerInfo = typeof(T).GetProperties();

            // 为 标头 创建 Array
            // 开始从 A1 处添加
            List<object> objHeaders = new List<object>();
            for (int n = 0; n < headerInfo.Length; n++)
            {
                objHeaders.Add(headerInfo[n].Name);
            }

            var headerToAdd = objHeaders.ToArray();
            AddExcelRows("A1", 1, headerToAdd.Length, headerToAdd);
            SetHeaderStyle();

            return headerToAdd;
        }
        /// 

        /// 列标题设置为加粗字体
        /// 
        private void SetHeaderStyle()
        {
            _font = _range.Font;
            _font.Bold = true;
        }
        /// 

        /// 添加行
        /// 
        /// 
        /// 
        /// 
        /// 
        private void AddExcelRows(string startRange, int rowCount,
        int colCount, object values)
        {
            _range = _sheet.get_Range(startRange, _optionalValue);
            _range = _range.get_Resize(rowCount, colCount);
            _range.set_Value(_optionalValue, values);
        }
        /// 

        /// 创建 Excel 传递的参数实例
        /// 
        private void CreateExcelRef()
        {
            _excelApp = new Excel.Application();
            _books = (Excel.Workbooks)_excelApp.Workbooks;
            _book = (Excel._Workbook)(_books.Add(_optionalValue));
            _sheets = (Excel.Sheets)_book.Worksheets;
            _sheet = (Excel._Worksheet)(_sheets.get_Item(1));
        }
        /// 

        /// 释放未使用的对象
        /// 
        /// 
        private void ReleaseObject(object obj)
        {
            try
            {
                System.Runtime.InteropServices.Marshal.ReleaseComObject(obj);
                obj = null;
            }
            catch (Exception ex)
            {
                obj = null;
                //MessageBox.Show(ex.Message.ToString());

            }
            finally
            {
                GC.Collect();
            }
        }
    }
    #endregion

四：导出按钮单击事件

/// 

        /// 导出为Excel
        /// 
        /// 
        /// 
        private void btnExport_Click(object sender, RoutedEventArgs e)
        {
            Common.ExportToExcel> exporttoexcel = 
                new Common.ExportToExcel>();
            //实例化exporttoexcel对象
            exporttoexcel.DataToPrint = (List)dgtOnlineRecord.ItemsSource;
            exporttoexcel.GenerateReport();

        }

导出的Excel：

小结

可能出现的问题及解决方案

需要添加引用：

使用命名空间：

using System.Reflection;
using Excel = Microsoft.Office.Interop.Excel;