C# 赋值的左侧必须是代码中的变量、属性或索引器 Microsoft.Office.Interop.Excel.Application xlApp； Microsoft.Office.Interop.Excel.工作簿； Microsoft.Office.Int

赋值的左侧必须是代码中的变量、属性或索引器

Microsoft.Office.Interop.Excel.Application xlApp；
Microsoft.Office.Interop.Excel.工作簿；
Microsoft.Office.Interop.Excel.Worksheet xlWorkSheet；
xlApp=新的Microsoft.Office.Interop.Excel.ApplicationClass（）；
xlWorkBook=xlApp.Workbooks.Add（Type.Missing）；
xlWorkSheet=（Microsoft.Office.Interop.Excel.Worksheet）xlWorkBook.Worksheets.get_项（1）；
int i=0；
int j=0；
如果（dgvSearchStudFees.Visible==true）
{
对于（i=0；i
Microsoft.Office.Interop.Excel.Application xlApp；
Microsoft.Office.Interop.Excel.工作簿；
Microsoft.Office.Interop.Excel.Worksheet xlWorkSheet；
xlApp=新的Microsoft.Office.Interop.Excel.ApplicationClass（）；
xlWorkBook=xlApp.Workbooks.Add（Type.Missing）；
xlWorkSheet=（Microsoft.Office.Interop.Excel.Worksheet）xlWorkBook.Worksheets.get_项（1）；
int i=0；
int j=0；
如果（dgvSearchStudFees.Visible==true）
{
对于（i=0；i
=
=>
=
），它应该是==不是=
            Microsoft.Office.Interop.Excel.Application xlApp;
            Microsoft.Office.Interop.Excel.Workbook xlWorkBook;
            Microsoft.Office.Interop.Excel.Worksheet xlWorkSheet;

            xlApp = new Microsoft.Office.Interop.Excel.ApplicationClass();
            xlWorkBook = xlApp.Workbooks.Add(Type.Missing);
            xlWorkSheet = (Microsoft.Office.Interop.Excel.Worksheet)xlWorkBook.Worksheets.get_Item(1);
            int i = 0;
            int j = 0;
            if (dgvSearchStudFees.Visible == true)
            {
                for (i = 0; i <= dgvSearchStudFees.RowCount - 1; i++)
                {
                    for (j = 0; j <= dgvSearchStudFees.ColumnCount - 1; j++)
                    {
                        DataGridViewCell cell = dgvSearchStudFees[j, i];
                        xlWorkSheet.Cells[i + 1, j + 1] = cell.Value;
                    }
                }
                var savefiledialog = new SaveFileDialog();
                savefiledialog.FileName = "Atharva ExcelSheet";
                savefiledialog.DefaultExt = ".xlsx";
                if (savefiledialog.ShowDialog()=DialogResult.OK)   // here I m getting an error "The left-hand side of an assignment must be a variable, property or indexer" Don't know what is wrong. Same as above If statement. its a code for exporting the Data Grid View data to Microsoft excel. I tried doing this code but still I don't understand why this error occurs.
                {
                    xlWorkBook.SaveAs(savefiledialog.FileName, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing,Microsoft.Office.Interop.Excel.XlSaveAsAccessMode.xlExclusive, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing);
                }
                xlApp.Quit();
            }

        Microsoft.Office.Interop.Excel.Application xlApp;
        Microsoft.Office.Interop.Excel.Workbook xlWorkBook;
        Microsoft.Office.Interop.Excel.Worksheet xlWorkSheet;

        xlApp = new Microsoft.Office.Interop.Excel.ApplicationClass();
        xlWorkBook = xlApp.Workbooks.Add(Type.Missing);
        xlWorkSheet = (Microsoft.Office.Interop.Excel.Worksheet)xlWorkBook.Worksheets.get_Item(1);
        int i = 0;
        int j = 0;
        if (dgvSearchStudFees.Visible == true)
        {
            for (i = 0; i <= dgvSearchStudFees.RowCount - 1; i++)
            {
                for (j = 0; j <= dgvSearchStudFees.ColumnCount - 1; j++)
                {
                    DataGridViewCell cell = dgvSearchStudFees[j, i];
                    xlWorkSheet.Cells[i + 1, j + 1] = cell.Value;
                }
            }
            var savefiledialog = new SaveFileDialog();
            savefiledialog.FileName = "Atharva ExcelSheet";
            savefiledialog.DefaultExt = ".xlsx";
            if (savefiledialog.ShowDialog() == DialogResult.OK)   // This should be == . "=" means assignment to left hand side
            {
                xlWorkBook.SaveAs(savefiledialog.FileName, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing,Microsoft.Office.Interop.Excel.XlSaveAsAccessMode.xlExclusive, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing);
            }
            xlApp.Quit();
        }