c# - 如何解决 Unable to cast object of type 'System.Data.DataView' to type 'System.Data.DataTable' ERROR

Question

我在窗体上有 Devxpress GridControl，
我想将此网格上的数据发送到 excel。
我不想用 ExportToExcel 方法来做到这一点
我用谷歌搜索并找到了这段代码
但此代码用于 .Net 的 DataGrid 控件并在尝试转换时出错 DevExpress.XtraGrid.Views.Grid.GridView 到 System.Data.DataView
这是代码

public string LastCoulmLetter(int coulmnCount)
{
        string finalColLetter = string.Empty;
        string colCharset = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
        int colCharsetLen = colCharset.Length;

        if (coulmnCount > colCharsetLen)
        {
            finalColLetter = colCharset.Substring(
                (coulmnCount - 1) / colCharsetLen - 1, 1);
        }

        finalColLetter += colCharset.Substring(
                (coulmnCount - 1) % colCharsetLen, 1);

        return finalColLetter;
}


public void FromGridToExcel()
{
        if (gridView1.RowCount <= 0)
            return;
        Excel.Application xls = new Excel.Application();
        Excel.Workbook wb;
        Excel.Worksheet sheet;

        object SalakObje = System.Reflection.Missing.Value;
        wb = xls.Workbooks.Add(SalakObje);
        sheet = (Excel.Worksheet)wb.ActiveSheet;
        sheet.Name = "Result";
        xls.Visible = true;

        DataTable dt = (DataTable)gridView1.DataSource; // Error comes in here

        // Copy the DataTable to an object array
        object[,] rawData = new object[dt.Rows.Count + 1, dt.Columns.Count];

        // Copy the column names to the first row of the object array
        for (int col = 0; col < dt.Columns.Count; col++)
        {
            rawData[0, col] = dt.Columns[col].ColumnName;
        }

        // Copy the values to the object array
        for (int col = 0; col < dt.Columns.Count; col++)
        {
            for (int row = 0; row < dt.Rows.Count; row++)
            {
                rawData[row + 1, col] = dt.Rows[row].ItemArray[col];
            }
        }

        // Fast data export to Excel
        string excelRange = string.Format("A1:{0}{1}",LastCoulmLetter(dt.Columns.Count), dt.Rows.Count + 1);

        sheet.get_Range(excelRange, Type.Missing).Value2 = rawData;

        sheet.get_Range(excelRange).Columns.AutoFit();
}

问题是什么以及如何解决

Answer 1

问题似乎是您的 DataSource 是 DataView，而不是 DataTable。

一些选项:

如果您想使用相同的过滤器，请将其转换为 DataView:

DataView dv = (DataView)gridView1.DataSource;

如果需要原始数据，请使用 .Table 属性获取源表:

DataTable dt = ((DataView)gridView1.DataSource).Table;