如何确定使用OLEDB在C＃中Excel工作簿是否受密码保护？

Question

I am reading an excel file using 'OLEDB' . I need a provision where I can determine whether excel file that I am accessing is password protected or not. Please find my code below:

private DataSet LoadExcel(string fileName, string tableName)
{
string path = fileName;
string connStr = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" + path + ";Extended Properties=Excel 12.0;";
System.Data.OleDb.OleDbConnection MyConnection;
System.Data.DataSet DtSet;
System.Data.OleDb.OleDbDataAdapter MyCommand;
MyConnection = new System.Data.OleDb.OleDbConnection(connStr);
MyConnection.Open();
DataTable dtExcelSchema;
dtExcelSchema = MyConnection.GetOleDbSchemaTable(System.Data.OleDb.OleDbSchemaGuid.Tables, null);
string SheetName = dtExcelSchema.Rows[0]["TABLE_NAME"].ToString();
MyCommand = new System.Data.OleDb.OleDbDataAdapter("select * from [" + SheetName + "]", MyConnection);
MyCommand.TableMappings.Add("Table", tableName);
DtSet = new System.Data.DataSet();
MyCommand.Fill(DtSet);
MyConnection.Close();
return DtSet;
}

My code is breaking up on line "MyConnection.Open();" because the excel file which it is accessing here is password-protected. If I could check that, I will bypass the code and display a user-friendly message. Please help if anyone has any idea on this front.

Thanks in Advance!!

Answer 1

From http://www.connectionstrings.com/excel/

If the Excel workbook is protected by a password, you cannot open it for data access, even by supplying the correct password with your connection string. If you try, you receive the following error message: "Could not decrypt file."

OLEDB connection will not work for password protected worksheets. If there is some exception, you can detect the exact type and catch it.

Other way is to use the Office API and use the HasPassword property.

Workbook book = '.....xyz''';
if (book.HasPassword) { ... }

Answer 2

Have you tried sth like that?

    try
    {
        MyConnection.Open();
    }
    catch (Exception ex)
    {
        Console.WriteLine(ex.Message);
    }

Answer 3

Per Aseem's first response, the "Could not decrypt file." problem is a result of the Excel file not being in a trusted location. I had the same problem and solved it by moving the Excel file to a trusted location or adding the folder that the Excel file is in to the Trusted Locations.