c# - 为什么我得到 System.IndexOutOfRangeException

Question

我还有另外两个按钮，代码几乎完全相同。但是，当我尝试运行此代码以获取所有结果时，出现错误“System.IndexOutOfRangeException”。

显示无效 NHS 号码按钮有效，但我不明白为什么它有效，但显示所有记录按钮无效。错误出现在较低代码块的 dgvResults 部分，但不是第一个。

 private void cmdShowInvalidNHSnumbers_Click(object sender, EventArgs e)
    {
        string databaseFilename;
        string sql;

        dgvResults.ColumnCount = 3;
        dgvResults.Columns[0].Name = "NHSNumber";
        dgvResults.Columns[1].Name = "Patient";
        dgvResults.Columns[2].Name = "Problem";

        dgvResults.Rows.Clear();

        databaseFilename = Application.StartupPath + "\\nhsnumberchecker.db";

        System.Data.SQLite.SQLiteConnection m_dbConnection;
        m_dbConnection = new System.Data.SQLite.SQLiteConnection("Data Source=" + databaseFilename + ";Version=3;");
        m_dbConnection.Open();

        sql = @"
        SELECT * FROM results
        -- WHERE NHSNumber = 'N'
        WHERE NHSNumberValid = 'N'
        ORDER BY Surname;";

        System.Data.SQLite.SQLiteCommand command = new System.Data.SQLite.SQLiteCommand(sql, m_dbConnection);

        System.Data.SQLite.SQLiteDataReader reader = command.ExecuteReader();
        while (reader.Read())
        {
            dgvResults.Rows.Add(reader["NHSNumber"], reader["Surname"] + ", " + reader["GivenName"], NHSnumberError(reader.GetString(0)));
        }

        dgvResults.Refresh();
        dgvResults.AutoResizeColumns();
        m_dbConnection.Close();
    }







 private void cmdShowAllResults_Click(object sender, EventArgs e)
    {
        string databaseFilename;
        string sql;

        dgvResults.ColumnCount = 7;
        dgvResults.Columns[0].Name = "NHSNumber";
        dgvResults.Columns[1].Name = "DOB";
        dgvResults.Columns[2].Name = "Title";
        dgvResults.Columns[3].Name = "Surname";
        dgvResults.Columns[4].Name = "GivenName";
        dgvResults.Columns[5].Name = "Gender";
        dgvResults.Columns[6].Name = "Problem";

        dgvResults.Rows.Clear();

        databaseFilename = Application.StartupPath + "\\nhsnumberchecker.db";

        System.Data.SQLite.SQLiteConnection m_dbConnection;
        m_dbConnection = new System.Data.SQLite.SQLiteConnection("Data Source=" + databaseFilename + ";Version=3;");
        m_dbConnection.Open();

        sql = @"
        SELECT * FROM results
        ORDER BY Surname;";

        System.Data.SQLite.SQLiteCommand command = new System.Data.SQLite.SQLiteCommand(sql, m_dbConnection);

        System.Data.SQLite.SQLiteDataReader reader = command.ExecuteReader();
        while (reader.Read())
        {
            dgvResults.Rows.Add(reader["NHSNumber"], reader["DOB"], reader["Title"], reader["Surname"] + ", " + reader["GivenName"],
                reader["Gender"], reader["Problem"], NHSnumberError(reader.GetString(0))); //This section is causing the error
        }

        dgvResults.Refresh();
        dgvResults.AutoResizeColumns();
        m_dbConnection.Close();
    }
}

代码的下半部分是收到错误消息的部分。我不明白它的哪一部分是“超出范围”。

Answer 1

也许您的查询结果包含一个“，”字符。
尝试修改所有条目，添加替换方法以查看是否为真:

dgvResults.Rows.Add(reader["NHSNumber"].Replace("," , "") , ............