adapter.Fill(table) 行未找到文件异常未处理

Question

我正在尝试连接到数据库 MySql 但出现了此错误

FileNotFoundException was unhandled

在 adapter.Fill 行中。

FileNotFoundException 未处理无法加载文件或程序集 'Renci.SshNet, Version=2016.1.0.0, Culture=neutral, PublicKeyToken=1cee9f8bde3db106' 或其依赖项之一。系统找不到指定的文件

class CONNECT
{
    private MySqlConnection connection = new MySqlConnection("Datasource=localhost;Port=3306;Username=root;Password=;Database=Csharp_Hotel_DB");

    //create a function to return our connection
    public MySqlConnection getConnection()
    {
        return connection;
    }

    //create a function to open the connection
    public void openConnection()
    {
        if (connection.State == ConnectionState.Closed)
        {
            connection.Open();

        }
    }

    //create a function to close the connection
    public void closeConnection()
    {
        if (connection.State == ConnectionState.Open)
        {
            connection.Close();

        }
    }
}

private void buttonLogin_Click(object sender, EventArgs e)
{
    CONNECT conn = new CONNECT();
    DataTable table = new DataTable();
    MySqlDataAdapter adapter = new MySqlDataAdapter();
    MySqlCommand command = new MySqlCommand();
    String query = "SELECT * FROM `users` WHERE `username`=@usn AND `password`=@pass";

    command.CommandText = query;
    command.Connection = conn.getConnection();

    command.Parameters.Add("@usn", MySqlDbType.VarChar).Value = textBoxUsername.Text;
    command.Parameters.Add("@pass", MySqlDbType.VarChar).Value = textBoxPassword.Text;

    adapter.SelectCommand = command;
    adapter.Fill(table); //this line is the FileNotFoundException was unhandled


    // if the username and the password exists
    if (table.Rows.Count > 0)
    {
        this.Hide();
        MessageBox.Show("YES");
        Main_Form mform = new Main_Form();
        mform.Show();
    }
    else
    {

        if (textBoxUsername.Text.Trim().Equals(""))
        {
            MessageBox.Show("Enter Your Username to Login", "Empty Username", MessageBoxButtons.OK, MessageBoxIcon.Error);
        }
        else if (textBoxPassword.Text.Trim().Equals(""))
        {
            MessageBox.Show("Enter Your Password to Login", "Empty Password", MessageBoxButtons.OK, MessageBoxIcon.Error);
        }
        else
        { 
            MessageBox.Show("Username and Password Doesn't Exists", "Wrong Data", MessageBoxButtons.OK, MessageBoxIcon.Error);
        }
    }
}

Answer 1

您似乎没有处理 adapter.fill 可以通过的异常。使用：

try{
    adapter.Fill(table);
} catch(FileNotFoundException e) {
    do stuff with e or your code
}

或者在使用之前检查路径是否存在。

Answer 2

您正在创建数据 table，但没有将名称传递给构造函数。这意味着 table 是无名的，因此当您尝试在无名的 table 上调用 Fill 时，您会得到找不到文件的异常。

您应该传入 table 名称

DataTable table = new DataTable("users");

Answer 3

它现在正在工作 c。使用 MySQL-connector-net-6.3.5 可以修复此错误或问题，因为我使用的是 .net 4

感谢您的帮助。

Answer 4

这是 MySQL Connector/NET、bug 96614 中的错误。它将在 Connector/NET 8.0.18.

中修复

Fixed as of the upcoming MySQL Connector/NET 8.0.18 release, and here's the changelog entry:

The Renci.SshNet.dll deployment was problematic for Connector/NET 8.0.17 MSI installations. Some applications, such as Microsoft Excel, were unable to read MySQL data as a result. This fix removes unnecessary dependencies on the DLL and also ensures that the MSI installation deploys the correct Renci.SshNet.dll to the GAC.

您现在可以使用的解决方法是切换到 MySqlConnector，MySQL 的替代 OSS ADO.NET 库，它没有这个错误。

adapter.Fill(table) 行未找到文件异常未处理

File Not Found Exception was unhandled in the line of adapter.Fill(table)

c#

mysql

ado.net

filenotfoundexception