Show a kind of messagebox

Leave a reply 
AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setMessage("Are you sure you want to exit?");

builder.setCancelable(false);
builder.setPositiveButton("Yes", new DialogInterface.OnClickListener()
{
public void onClick(DialogInterface dialog, int id)
{
MainActivity.this.finish();
}
});

builder.setNegativeButton("No", new DialogInterface.OnClickListener()
{
public void onClick(DialogInterface dialog, int id)
{
dialog.cancel();
}
});

builder.setNeutralButton("Test", new DialogInterface.OnClickListener()
{
public void onClick(DialogInterface dialog, int id)
{


}
});

AlertDialog alert = builder.create();
alert.show();

Attach items to a listview

Leave a reply

A listview shows data provided by an adapter. To create a simple list use the following:

//Find the listview with id 'list' in the resources 
ListView listView = (ListView) findViewById(R.id.list);

//Make a connection through an adapter 
listView.setAdapter(new ArrayAdapter<String>(MainActivity.this, android.R.layout.simple_list_item_1, new String[] {"AAA", "BBB", "CCC"}));

Showing time in DataGridView column

Leave a reply

To show time in a DataGridView column set the column type to DataGridViewTextBoxColumn.
Set the columns DefaultCellStyle Format to ‘t’. You can do this in the designer or use the following code:

myGridView.Columns[0].DefaultCellStyle.Format = “t”; //0 is the required column, change if needed.

Now you can assign a DateTime to the cell value and time will show in the users preferred format (‘t’).

Check whether a form is valid.

Leave a reply

When using modeless forms the user can close  the form manually. Use the created property to check whether this is the case.

Example:

class Form1 : Form
{
   Form2 modelessForm = null;

   //On mouse click show Form2
   void onMouseClick(MouseButtons button, int x, int y)
   {
      if (modelessForm == null || !modelessForm.Created)
      {
         modelessForm = new Form2()
      }

      modelessForm.Show();
   }
}

Executing a SQL stored procedure and read the result

Leave a reply

Self explanatory snippet

SqlConnection db = new SqlConnection(Properties.Settings.Default.ConnectionString);

try
{
   db.Open();

   SqlCommand cmd = new SqlCommand("storedProcedureName", db);
   cmd.CommandType = CommandType.StoredProcedure;
   cmd.Parameters.Add(new SqlParameter("@parm1", SqlDbType.Int, 4));
   cmd.Parameters.Add(new SqlParameter("@parm2", SqlDbType.Text));
   cmd.Parameters["@parm1"].Value = 1234;
   cmd.Parameters["@parm2"].Value = "ABC";

   SqlDataReader dataReader = cmd.ExecuteReader();

   DataTable storedTable = new DataTable();
   storedTable.Load(dataReader);
                
   foreach (DataRow row in storedTable.Rows)
   {
      //Here row contains the retrieved data.
      int test = Convert.ToInt32(row[0]);
   }
   storedTable.Dispose();
   dataReader.Dispose();
   cmd.Dispose();
          
   db.Close(); 
   db.Dispose(); 
   db = null;
}
catch (Exception e)
{
   System.Windows.Forms.MessageBox.Show(e.Message, "DB error", System.Windows.Forms.MessageBoxButtons.OK, System.Windows.Forms.MessageBoxIcon.Error);      
}

Reading from a SQL database

Leave a reply

Self explanatory snippet


SqlConnection db = new SqlConnection(Properties.Settings.Default.ConnectionString);

            
try
{
   db.Open();
   SqlDataAdapter dataAdapter = new SqlDataAdapter("SELECT FirstName, LastName  FROM Contacts", db);

   DataTable dataTable = new DataTable();
   dataAdapter.Fill(dataTable);

   foreach(DataRow row in dataTable.Rows)
   {
      string firstName = row["FirstName"];
      string lastName  = row["LastName"];
   }
 
   db.Close(); 
   db.Dispose(); 
   db = null;0
}
catch (Exception e)
{
   System.Windows.Forms.MessageBox.Show(e.Message, "DB error", System.Windows.Forms.MessageBoxButtons.OK, System.Windows.Forms.MessageBoxIcon.Error);      
}