C# 如何在.NET应用程序中正确检查与mysql的数据库连接？

首先，我想说的是，我一直在互联网上寻找解决我问题的方法，而我所找到的只是经典

if(connection.open) return true; 

解决方案在我的情况下不适合我的需要

我正在写一份申请书。在运行之前，我需要检查与MySQL数据库的连接，如果连接未完成，将打开一个新窗口，提示用户进行连接设置用户名、服务器地址、密码。。。。在此窗口中，我有一个测试连接按钮，以查看是否建立了连接，这是按钮单击事件的代码：

private void Button_Click_1(object sender, RoutedEventArgs e)
{
    ApplicationSettings applicationSettings = new ApplicationSettings();

    applicationSettings.ServerDatabase = tbdbName.Text;
    applicationSettings.ServerIp = tbServer.Text;
    applicationSettings.ServerUserName = tbUsername.Text;
    //applicationSettings.ServerPassword = pbPassword.SecurePassword;
    applicationSettings.MakeConnectionString();
    MySqlConnection connection = new MySqlConnection(applicationSettings.ConnectionString);
    try
    {
        connection.Open();

        MessageBox.Show(this, "connection string: "+applicationSettings.ConnectionString+"connection OK!", "OK !", MessageBoxButton.OK, MessageBoxImage.Information);
    }
    catch (Exception ee)
    {
        MessageBox.Show(this, "connection string : "+applicationSettings.ConnectionString+"error : " + ee.Message, "connection ERROOOOR", MessageBoxButton.OK,
            MessageBoxImage.Error);

    }
    finally
    {
        if(connection.State == ConnectionState.Open)
            connection.Close();
    }

}

如果仅输入服务器地址applicationSettings.ServerIp并单击测试连接按钮，则会显示消息框OK，连接字符串为：

服务器=127.0.0.1；数据库=；密码=

我想这是完全合乎逻辑的，但是我需要测试是否建立了到数据库的连接，如果我用任意值填充登录文本框，那么连接就建立了

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问题：如何使用此选项测试是否与数据库建立了连接？

连接到数据库，发出一个简单的查询，如SELECT 1 from，并确保成功接收回“1”。这证实你有

连接到物理服务器没有网络问题 使用数据库服务器进行身份验证数据库正在运行，并且您具有正确的凭据 已连接到正确的数据库

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连接到数据库，发出一个简单的查询，如SELECT 1 from，并确保成功接收回“1”。这证实你有

连接到物理服务器没有网络问题 使用数据库服务器进行身份验证数据库正在运行，并且您具有正确的凭据 已连接到正确的数据库 试试这个：

private void Button_Click_1(object sender, RoutedEventArgs e)
{
    ApplicationSettings applicationSettings = new ApplicationSettings();
    applicationSettings.ServerIp = tbServer.Text;
    applicationSettings.MakeConnectionString();
   try
    {
         MySqlConnection connection = new MySqlConnection(applicationSettings.ConnectionString);
        connection.Open();
        MessageBox.Show(this, "server found", "OK !", MessageBoxButton.OK, MessageBoxImage.Information);
        connection.Close();
        applicationSettings.ServerDatabase = tbdbName.Text;
            try{
                applicationSettings.MakeConnectionString();
                connection = new MySqlConnection(applicationSettings.ConnectionString);
                connection.Open();
                MessageBox.Show(this, "Database found", "OK !", MessageBoxButton.OK, MessageBoxImage.Information);
                connection.Close();
                applicationSettings.ServerUserName = tbUsername.Text;
                applicationSettings.ServerPassword = pbPassword.SecurePassword;
                        try{
                            applicationSettings.MakeConnectionString();
                            connection = new MySqlConnection(applicationSettings.ConnectionString);
                            connection.Open();
                            MessageBox.Show(this, "Server,database and account are valid", "OK !", MessageBoxButton.OK, MessageBoxImage.Information);
                            }
                        catch(Exception ee){
                                           MessageBox.Show(this, "Error: Account  parameters not valid!! " + ee.Message, "connection ERROOOOR", MessageBoxButton.OK,
                                           MessageBoxImage.Error);
                                           }
                           }
             catch(Exception ee){
                            MessageBox.Show(this, "Error: server is connected but the database not found!! " + ee.Message, "connection ERROOOOR", MessageBoxButton.OK,
                            MessageBoxImage.Error);
                                 }
    }
    catch (Exception ee)
    {
        MessageBox.Show(this, "Error: server not found " + ee.Message, "connection ERROOOOR", MessageBoxButton.OK,
            MessageBoxImage.Error);

    }
    finally
    {
        if(connection.State == ConnectionState.Open)
            connection.Close();
    }

}

也许它对你有帮助

试试这个：

private void Button_Click_1(object sender, RoutedEventArgs e)
{
    ApplicationSettings applicationSettings = new ApplicationSettings();
    applicationSettings.ServerIp = tbServer.Text;
    applicationSettings.MakeConnectionString();
   try
    {
         MySqlConnection connection = new MySqlConnection(applicationSettings.ConnectionString);
        connection.Open();
        MessageBox.Show(this, "server found", "OK !", MessageBoxButton.OK, MessageBoxImage.Information);
        connection.Close();
        applicationSettings.ServerDatabase = tbdbName.Text;
            try{
                applicationSettings.MakeConnectionString();
                connection = new MySqlConnection(applicationSettings.ConnectionString);
                connection.Open();
                MessageBox.Show(this, "Database found", "OK !", MessageBoxButton.OK, MessageBoxImage.Information);
                connection.Close();
                applicationSettings.ServerUserName = tbUsername.Text;
                applicationSettings.ServerPassword = pbPassword.SecurePassword;
                        try{
                            applicationSettings.MakeConnectionString();
                            connection = new MySqlConnection(applicationSettings.ConnectionString);
                            connection.Open();
                            MessageBox.Show(this, "Server,database and account are valid", "OK !", MessageBoxButton.OK, MessageBoxImage.Information);
                            }
                        catch(Exception ee){
                                           MessageBox.Show(this, "Error: Account  parameters not valid!! " + ee.Message, "connection ERROOOOR", MessageBoxButton.OK,
                                           MessageBoxImage.Error);
                                           }
                           }
             catch(Exception ee){
                            MessageBox.Show(this, "Error: server is connected but the database not found!! " + ee.Message, "connection ERROOOOR", MessageBoxButton.OK,
                            MessageBoxImage.Error);
                                 }
    }
    catch (Exception ee)
    {
        MessageBox.Show(this, "Error: server not found " + ee.Message, "connection ERROOOOR", MessageBoxButton.OK,
            MessageBoxImage.Error);

    }
    finally
    {
        if(connection.State == ConnectionState.Open)
            connection.Close();
    }

}

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也许它对你有帮助

thnks@Babak，那有帮助thnks@Babak，那有帮助