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How to load the datagridview using OOP C#

I am a beginner at C# and .NET oop concepts. I want to load the datagridview. I don't know how to pass the data. What I tried so far I attached below.
I created a class std
public void get()
{
SqlConnection con = new SqlConnection("server =.; initial catalog=testdb; User ID=sa; Password=123");
string sql = "select * from std";
con.Open();
SqlCommand cm = new SqlCommand(sql, con);
SqlDataReader dr = cm.ExecuteReader();
while ( dr.Read())
{
string stname = dr["st_name"].ToString();
string nicnum = dr["nic"].ToString();
}
con.Close();
}
Form: I am getting data like this way
std ss = new std();
ss.get();
dataGridView1.Rows.Clear();
If I wrote like this way how to pass data into the datagridview columns? I am stuck in this area

It's easier like this:
public void FillGrid()
{
var dt = new DataTable();
var da = new SqlDataAdapter("select * from std", "server =.; initial catalog=testdb; User ID=sa; Password=123");
da.Fill(dt);
dataGridView1.DataSource = dt;
}
but if you're going to use such a low level method of database access you should consider adding a DataSet type of file to your project; visual studio will write all this code and more for you with a few mouse clicks, and it makes a good job of creating tables and adapters that are a lot easier to work with

you have made multiple mistakes. First you read data wirh dataraeader and in every iteration define two stname and nimnum variables like. So when loop ends variables are destroyed. You have to define data table and read data by dataraeader and and add them to it row by row. Or read by sqldataadapter and read it immediately and pass to datatable object.Finnaly you pass datatable as return object of function. Use this vala as datasource of datagridview property if I'm not wrong.

Updating Database When Dataset Filled from View (not table)

Background: I have a Windows Forms Application with a DataGridView control that is bound to a DataSet. The DataSet is filled with data from a database view. Some of the DataGridView cells are editable, and rows need to be delete-able.
Problem: When a value in the grid is edited, how do I update the database? It does not appear to be nearly as easy as it would be if it were pointing to a database table, rather than a view. Should I be adding the tables relevant to the view to the DataSet as well, and then making the appropriate changes to the tables and then calling the update DataSet method?
Edit1: I think DataSets that point to a view with joins cannot have the Update() method called.
Edit2: With the below code, I get an error saying:
there is no definition for Update
when my DataSet looks at a view. However, if a DataSet points to a table, Update does exist. Both DataSet are autogenerated by VS. What am I doing wrong?
try
{
this.ASSIGNMENTS_VWTableAdapter.Update(this.TEST_Dataset.ASSIGNMENTS_VW);
}
catch(Exception ex)
{
MessageBox.Show(ex.Message);
}
Edit3: The following code is what I used to try the SqlCommandBuilder. I get the error I mentioned in my comment below "Dynamic SQL generation is not supported against multiple base tables."
using (SqlConnection connection = new SqlConnection(connectionString))
{
SqlDataAdapter adapter = new SqlDataAdapter();
adapter.SelectCommand = new SqlCommand("SELECT * FROM ASSIGNMENTS_VW", connection);
SqlCommandBuilder builder = new SqlCommandBuilder(adapter);
connection.Open();
builder.GetUpdateCommand();
adapter.Update(tEST_ASSIGNMENTS_VW, "ASSIGNMENTS_VW");
}

DataSet is not updated in visual studio 2010

I am new to visual studio-2010. I am trying to create an application which reads data from sql database and shows on datagrid. I implemented the code which I found on internet.
here is the sql_button_Click function
private void sql_button_Click(object sender, RoutedEventArgs e)
{
string ConnectionString = "Data Source=.\\SQLEXPRESS;AttachDbFilename='C:\\Users\\jakkulv\\Downloads\\VS projects\\employee\\employee\\SampleDatabase.mdf';Integrated Security=True;Connect Timeout=30;User Instance=True";
string SQL = "select emp_id,first_name from employee";
SqlConnection conn = new SqlConnection(ConnectionString);
// open the connection
conn.Open();
//Create a SqlDataAdapter object
SqlDataAdapter adapter = new SqlDataAdapter(SQL, conn);
// Call DataAdapter's Fill method to fill data from the
// Data Adapter to the DataSet
DataSet ds = new DataSet("employee"); //database table name is "employee"
ds.Clear();
adapter.Fill(ds);
// Bind data set to a DataGrid control
dataGrid1.ItemsSource = ds.DefaultViewManager;
if (ds.HasChanges(DataRowState.Added))
{
// New rows have been added to the dataset, add appropriate code.
MessageBox.Show("data set has changes");
}
else
{
MessageBox.Show("data set has no changes");
// No new rows have been added to the dataset, add appropriate code.
}
but when I execute the same it is showing the message box saying - "data set has no changes".
why dataset is not updated??How to update it??

Your code will always result in the message box with data set has no changes, since it doesn't have any changes.
The data is the same as when it comes from the database, and since you haven't modified it, removed any records or added any records, there are no changes.
Just as the MSDN docs say
Gets a value indicating whether the DataSet has changes, including new, deleted, or modified rows.
Try to modify it, and then call ds.HasChanges() and you'll see that it will return true.

Initialise Table adapter manually

How would I go about initialising a table adapter properly pragmatically? Normally, I would use the table adapter that get's created for me when I drag and drop the Data Table onto my form, but have never used one in a custom class before.
Cheers!
EDIT:
I think I need to explain my scenario in more detail.
I've added a method on my datatable inside my dataset. I want to be able to call this method from inside a custom class. Therefore I'd need a valid Table Adapter to be created to allow me to do this.

Just like this:
var dt = new DataTable();
using (SqlConnection c = new SqlConnection(cString))
using (SqlDataAdapter sda = new SqlDataAdapter("SELECT ...", c))
{
sda.SelectCommand.Parameters.AddWithValue("#field1", field1);
etc...
sda.Fill(dt);
}

void FillData()
{
// 1
// Open connection
using (SqlConnection c = new SqlConnection(
Properties.Settings.Default.DataConnectionString))
{
c.Open();
// 2
// Create new DataAdapter
using (SqlDataAdapter a = new SqlDataAdapter(
"SELECT * FROM EmployeeIDs", c))
{
// 3
// Use DataAdapter to fill DataTable
DataTable t = new DataTable();
a.Fill(t);
// 4
// Render data onto the screen
// dataGridView1.DataSource = t; // <-- From your designer
}
}
}
EDIT:
Why don't you make this method in a separate class that will be called in your data table and wherever else you will need to? You will just make an instance of the class and call the public method of that class.

c# windows forms / basic data grid

One of the problems I am having with c# is that there seems to be so much information online that I am having trouble finding the right answer to the most basic of questions.
I am trying to do something simple:
I have a button, I click it, it queries the database and populates a datagrid on my windows form.
private void button1_Click(object sender, EventArgs e)
{
SqlConnection c = new SqlConnection("Data Source = (local); Integrated Security = true; Initial Catalog = pubs; ");
c.Open();
// 2
// Create new DataAdapter
SqlCommand cmd = c.CreateCommand();
cmd.CommandText = #" SELECT * FROM Authors ";
SqlDataReader reader = cmd.ExecuteReader();
dataGridView1.DataSource = reader;
dataGridView1.DataBind();
}
Error 1 'System.Windows.Forms.DataGridView' does not contain a definition for 'DataBind' and no extension method 'DataBind' accepting a first argument of type 'System.Windows.Forms.DataGridView' could be found.....
I am probably missing a "using directive" but which one? Multiple Google searches tell me how to bind a Yahoo RSS Feed to a gridview or provide various obscure details on "using directives".
Maybe I am using the SqlDataReader incorrectly. Should I be using SqlAdapter instead? What happened to all the good basic tutorials online for windows c# forms? A few months ago I found a couple great tutorials, but they seem to have lost their pageranking and I cannot find them anymore using basic google searches.

You're not missing a using directive; it's just that the WinForms DataGridView doesn't have a DataBind method. Just assigning DataSource is enough to get the binding to happen; you don't need to call a method as well.
However, I don't think you can assign a SqlDataReader as the DataSource. According to the DataSource property documentation in MSDN, the DataSource must be an IList, an IListSource, an IBindingList or an IBindingListView. You will probably instead need to load the data into a DataTable or DataSet (or an object data source populated using an object-relational mapper), and use that as the DataSource.

Try this instead:
using (SqlConnection conn = new SqlConnection("your connection string"))
{
conn.Open();
using (SqlCommand cmd = new SqlCommand(#"SELECT * FROM Authors", conn))
{
using (SqlDataAdapter adap = new SqlDataAdapter(cmd))
{
DataTable dt = new DataTable();
adap.Fill(dt);
dataGridView1.DataSource = dt;
}
}
}
The DataGridView does not have a DataBind() method because it doesn't need one. Setting the DataSource property handles the binding for you. The using() blocks will automatically close and dispose of everything for you as well.
Note: you should replace "your connection string" with a valid connection string. I left yours out of my sample to avoid the horizontal scrollbars, and I'm not sure yours is valid anyway. You may get a runtime error when you run the code using your connection string. www.connectionstrings.com is a great resource for figuring out a valid connection string.
Update: instead of the nested using() blocks, you can also do it like this:
using (SqlConnection conn = new SqlConnection("..."))
using (SqlCommand cmd = new SqlCommand(#" SELECT * FROM Authors", conn))
using (SqlDataAdapter adap = new SqlDataAdapter(cmd))
{
conn.Open();
DataTable dt = new DataTable();
adap.Fill(dt);
dataGridView1.DataSource = dt;
}
I prefer the nested style, but it's "half of one, six dozen of the other" to me. Typically, I would encapsulate code like this into a class (called "DataGetter" or whatever) with a static method like:
public static DataTable GetData(string query)
{
// do all the connecting and adapting and filling and so forth
}
so that the code in your button click would be as simple as:
dataGridView1.DataSource = DataGetter.GetData("SELECT * FROM AUTHORS");
However, I would not do this in any performance-critical section of my code, since you sometimes want to keep a SqlCommand object (and its SqlParameter collection) around between calls. You do not need to keep SqlConnection objects around between calls, thanks to connection pooling (in fact, you don't want to keep them around under any circumstances).