如何在SQLite C＃中添加参数？

Question

我正在使用WPF和SQLite，我想添加新的参数。我想：

string _search; 

private void txtSearchBox_TextChanged(object sender, TextChangedEventArgs e) 
{ 
    _search = txtSearchBox.Text; 
} 

SQLiteConnection sqlite_conn = new SQLiteConnection("Data Source = music.db"); 
SQLiteCommand sqlite_cmd = new SQLiteCommand(); 

private void btn_search_Click(object sender, RoutedEventArgs e) 
{ 
    sqlite_conn.Open(); 
    sqlite_cmd = sqlite_conn.CreateCommand(); 
    sqlite_cmd.CommandText = "select Title from Song where Title=@title"; 

    sqlite_cmd.Parameters.Add("@title",SqlDbType.NVarChar, -1); // ************ // 

    sqlite_cmd.Parameters["@title"].Value = _search; 


    DataSet dataSet = new DataSet(); 
    SQLiteDataAdapter dataAdapter = new SQLiteDataAdapter(sqlite_cmd.CommandText,sqlite_conn); 
    dataAdapter.Fill(dataSet); 

    datagrid.ItemsSource = dataSet.Tables[0].DefaultView; 
} 

我对我打勾// ******* //行了错误。我该如何解决它？

Answer 1

除了对字符串类型列指定负大小之外，我没有看到任何错误。宁可尝试像

sqlite_cmd.Parameters.Add("@title",SqlDbType.NVarChar, 30);