C＃根据组合框选择显示DataGridView

Question

我需要有关C＃windows窗体应用程序的帮助。

我在我的表单中创建了一个DataGridView，DataGridView只需显示取决于用户的comobobox选择，组合框有三个选择，每个选择需要显示不同的数据库表，例如，如果他们选择仓库1然后将显示仓库1数据库中的数据库表。如果他们选择仓库2，那么将显示数据库表仓库2和仓库3的相同内容。

每个仓库如果不同的数据库。到目前为止，我只是在没有组合框选择的情况下添加仓库1时工作，但我需要基于组合框选择。

创建每个函数到get数据库表之后，将在每个数据库的form1方法中调用

这是我的代码

 private void Form1_Load(object sender, EventArgs e)
        {

            // Bind the DataGridView to the BindingSource
            // and load the data from the database.

            if (cmb_DatabaseSelection.SelectedItem == "warehouse1")
            {
                dataGridView_ShowAllData.DataSource = bindingSource;

                GetLeMarsConnectionDatabaseConnection("Select * from dbo.AllInvoicesInReadyStatus");
            }

            if (cmb_DatabaseSelection.SelectedItem == "warehouse2")
            {
                dataGridView_ShowAllData.DataSource = bindingSource;

                GetLeMarsConnectionDatabaseConnection("Select * from dbo.AllInvoicesInReadyStatus");
            }

            if (cmb_DatabaseSelection.SelectedItem == "warehouse3")
            {
                dataGridView_ShowAllData.DataSource = bindingSource;

                GetLeMarsConnectionDatabaseConnection("Select * from dbo.AllInvoicesInReadyStatus");
            }



            this.rpt_CallSSRSReport.RefreshReport();

            CallReport();
        }


private void GetLeMarsConnectionDatabaseConnection(string selectCommand)
        {


            try
            {

                //Create the connection string, data adapter and data table.
                String connectionString = "database1";


                // Specify a connection string. Replace the given value with a 
                // database accessible to your system.

                // Create a new data adapter based on the specified query.
                dataAdapter = new SqlDataAdapter(selectCommand, connectionString);

                // Create a command builder to generate SQL update, insert, and
                // delete commands based on selectCommand. These are used to
                // update the database.
                SqlCommandBuilder commandBuilder = new SqlCommandBuilder(dataAdapter);

                // Populate a new data table and bind it to the BindingSource.
                System.Data.DataTable table = new System.Data.DataTable();
                table.Locale = System.Globalization.CultureInfo.InvariantCulture;
                dataAdapter.Fill(table);
                bindingSource.DataSource = table;

                // Resize the DataGridView columns to fit the newly loaded content.
                dataGridView_ShowAllData.AutoResizeColumns(DataGridViewAutoSizeColumnsMode.AllCellsExceptHeader);

            }
            catch (SqlException)
            {
                MessageBox.Show("Database connection ERROR");
            }

        }

        private void GetSchuylerConnectionDatabaseConnection(string selectCommand)
        {
            try
            {

                //Create the connection string, data adapter and data table.
                String connectionString = "database2";


                // Specify a connection string. Replace the given value with a 
                // database accessible to your system.

                // Create a new data adapter based on the specified query.
                dataAdapter = new SqlDataAdapter(selectCommand, connectionString);

                // Create a command builder to generate SQL update, insert, and
                // delete commands based on selectCommand. These are used to
                // update the database.
                SqlCommandBuilder commandBuilder = new SqlCommandBuilder(dataAdapter);

                // Populate a new data table and bind it to the BindingSource.
                System.Data.DataTable table = new System.Data.DataTable();
                table.Locale = System.Globalization.CultureInfo.InvariantCulture;
                dataAdapter.Fill(table);
                bindingSource.DataSource = table;

                // Resize the DataGridView columns to fit the newly loaded content.
                dataGridView_ShowAllData.AutoResizeColumns(DataGridViewAutoSizeColumnsMode.AllCellsExceptHeader);

            }
            catch (SqlException)
            {
                MessageBox.Show("Database connection ERROR");
            }

        }

        private void GetDetroitLakesConnectionDatabaseConnection(string selectCommand)
        {
            try
            {

                //Create the connection string, data adapter and data table.
                String connectionString = "database3";


                // Specify a connection string. Replace the given value with a 

                // database accessible to your system.

                // Create a new data adapter based on the specified query.
                dataAdapter = new SqlDataAdapter(selectCommand, connectionString);

                // Create a command builder to generate SQL update, insert, and
                // delete commands based on selectCommand. These are used to
                // update the database.
                SqlCommandBuilder commandBuilder = new SqlCommandBuilder(dataAdapter);

                // Populate a new data table and bind it to the BindingSource.
                System.Data.DataTable table = new System.Data.DataTable();
                table.Locale = System.Globalization.CultureInfo.InvariantCulture;
                dataAdapter.Fill(table);
                bindingSource.DataSource = table;

                // Resize the DataGridView columns to fit the newly loaded content.
                dataGridView_ShowAllData.AutoResizeColumns(DataGridViewAutoSizeColumnsMode.AllCellsExceptHeader);

            }
            catch (SqlException)
            {
                MessageBox.Show("Database connection ERROR");
            }

        }

Answer 1

（1）双击组合框。以下代码将出现在您的代码中

    private void cmb_DatabaseSelection_SelectedIndexChanged(object sender, EventArgs e)
    {

    }

或者您也可以添加此类活动

将以下代码添加到上述功能中（根据您的需要编码）

if (cmb_DatabaseSelection.SelectedItem == "warehouse1")
        {
            dataGridView_ShowAllData.DataSource = bindingSource;

            GetLeMarsConnectionDatabaseConnection("Select * from dbo.AllInvoicesInReadyStatus");
        }

        if (cmb_DatabaseSelection.SelectedItem == "warehouse2")
        {
            dataGridView_ShowAllData.DataSource = bindingSource;

            GetLeMarsConnectionDatabaseConnection("Select * from dbo.AllInvoicesInReadyStatus");
        }

        if (cmb_DatabaseSelection.SelectedItem == "warehouse3")
        {
            dataGridView_ShowAllData.DataSource = bindingSource;

            GetLeMarsConnectionDatabaseConnection("Select * from dbo.AllInvoicesInReadyStatus");
        }