Non riesco a capire dove sbaglio! :-)

I parametri credo siano passati correttamente...

int rowsAffected = 0;
dbConnection.Open();
try {
rowsAffected = dbCommand.ExecuteNonQuery(); « QUI c'è ERRORE
}
finally {
dbConnection.Close();
}
return rowsAffected;
}

Errore : Tipi di dati non corrispondenti nell'espressione criterio
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Di seguito il codice indagato
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int InsAnnuncio(int iDGrp, int iDStGrp, System.DateTime dataIni, System.DateTime dataFin, string titolo, string testo, string eMail, string tel, string prezzo) {
string connectionString = "Provider=Microsoft.Jet.OLEDB.4.0; Ole DB Services=-4; Data Source=K:\\WebGrp\\Web60" +
"\\Locale\\Colombo\\appannunci\\smannunci.mdb" ;
System.Data.IDbConnection dbConnection = new System.Data.OleDb.OleDbConnection(connectionString );

string queryString = @"INSERT INTO [Annunci] ([IDGrp], [IDStGrp], [DataIni], [DataFin], [Titolo], [Testo], [EMail], [Tel], [Prezzo], [Attivo] ) VALUES (@IDGrp, @IDStGrp, @DataIni, @DataFin, @Titolo, @Testo, @EMail, @Tel, @Prezzo, false)";
System.Data.IDbCommand dbCommand = new System.Data.OleDb.OleDbCommand();
dbCommand.CommandText = queryString;
dbCommand.Connection = dbConnection;

System.Data.IDataParameter dbParam_iDGrp = new System.Data.OleDb.OleDbParameter();
dbParam_iDGrp.ParameterName = "@IDGrp";
dbParam_iDGrp.Value = iDGrp;
dbParam_iDGrp.DbType = System.Data.DbType.Int32;
dbCommand.Parameters.Add(dbParam_iDGrp);
System.Data.IDataParameter dbParam_iDStGrp = new System.Data.OleDb.OleDbParameter();
dbParam_iDStGrp.ParameterName = "@IDStGrp";
dbParam_iDStGrp.Value = iDStGrp;
dbParam_iDStGrp.DbType = System.Data.DbType.Int32;
dbCommand.Parameters.Add(dbParam_iDStGrp);
System.Data.IDataParameter dbParam_dataIni = new System.Data.OleDb.OleDbParameter();
dbParam_dataIni.ParameterName = "@DataIni";
dbParam_dataIni.Value = dataIni;
dbParam_dataIni.DbType = System.Data.DbType.DateTime;
dbCommand.Parameters.Add(dbParam_dataIni);
System.Data.IDataParameter dbParam_dataFin = new System.Data.OleDb.OleDbParameter();
dbParam_dataFin.ParameterName = "@DataFin";
dbParam_dataFin.Value = dataFin;
dbParam_dataFin.DbType = System.Data.DbType.DateTime;
dbCommand.Parameters.Add(dbParam_dataFin);
System.Data.IDataParameter dbParam_titolo = new System.Data.OleDb.OleDbParameter();
dbParam_titolo.ParameterName = "@Titolo";
dbParam_titolo.Value = titolo;
dbParam_titolo.DbType = System.Data.DbType.String;
dbCommand.Parameters.Add(dbParam_titolo);
System.Data.IDataParameter dbParam_testo = new System.Data.OleDb.OleDbParameter();
dbParam_testo.ParameterName = "@Testo";
dbParam_testo.Value = testo;
dbParam_testo.DbType = System.Data.DbType.String;
dbCommand.Parameters.Add(dbParam_testo);
System.Data.IDataParameter dbParam_eMail = new System.Data.OleDb.OleDbParameter();
dbParam_eMail.ParameterName = "@EMail";
dbParam_eMail.Value = eMail;
dbParam_eMail.DbType = System.Data.DbType.String;
dbCommand.Parameters.Add(dbParam_eMail);
System.Data.IDataParameter dbParam_tel = new System.Data.OleDb.OleDbParameter();
dbParam_tel.ParameterName = "@Tel";
dbParam_tel.Value = tel;
dbParam_tel.DbType = System.Data.DbType.String;
dbCommand.Parameters.Add(dbParam_tel);
System.Data.IDataParameter dbParam_prezzo = new System.Data.OleDb.OleDbParameter();
dbParam_prezzo.ParameterName = "@Prezzo";
dbParam_prezzo.Value = prezzo;
dbParam_prezzo.DbType = System.Data.DbType.String;
dbCommand.Parameters.Add(dbParam_prezzo);

int rowsAffected = 0;
dbConnection.Open();
try {
rowsAffected = dbCommand.ExecuteNonQuery();
}
finally {
dbConnection.Close();
}

return rowsAffected;
}



void btn_ins_Click(object sender, EventArgs e) {

InsAnnuncio(Convert.ToInt32 ddl_Rub.SelectedItem.Value),Convert.ToInt32(ddl_St Rub.SelectedItem.Value),System.DateTime.Now,System .DateTime.Now,tb_titolo.Text,tb_annuncio.Text,tb_e mail.Text,tb_telefono.Text,tb_prezzo.Text);

}

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Aiuto!

ciao e grazie