Tuesday, October 31, 2006

detailed explanation of application.settings in C#.net 2005

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnvs05/html/SettingsCS_RL.asp

Monday, October 30, 2006

make databound checkbox checked in C#.net2005 winform application

normal checkbox can use checkbox1.checked = true;

databound checkbox needs to change the checkstate: checkbox1.checkstate = checkstate.checked;

make databound checkbox checked in C#.net2005 winform application

normal checkbox can use checkbox1.checked = true;

databound checkbox needs to change the checkstate: checkbox1.checkstate = checkstate.checked;

check whether form is already opened in C#.net 2k5 winform application

created the form object in application settings

Code to open the form:
private void button1_Click(object sender, EventArgs e) {

if ( Properties.Settings.Default.frmReg == null )
{
Properties.Settings.Default.frmReg = new frmRegistration();
Properties.Settings.Default.frmReg.Show( this );
}
else if ( Properties.Settings.Default.frmReg != null && Properties.Settings.Default.frmReg.WindowState ==

FormWindowState.Minimized)
{
Properties.Settings.Default.frmReg.WindowState = FormWindowState.Normal ;
}
else
{
Properties.Settings.Default.frmReg.Focus();
}
}

Code to close the opened form:
Properties.Settings.Default.frmReg = null;

something wrong with goggle?

what's happening with blogger.com? the whole weekend and this monday morning, sometimes can't create a new post, sometimes changes to the template are not reflected, come on!!!!!

Sunday, October 29, 2006

check whether form is already opened in C#.net 2k5 winform application

created the form object in application settings

Code to open the form:
private void button1_Click(object sender, EventArgs e) {

if ( Properties.Settings.Default.frmReg == null )
{
Properties.Settings.Default.frmReg = new frmRegistration();
Properties.Settings.Default.frmReg.Show( this );
}
else if ( Properties.Settings.Default.frmReg != null && Properties.Settings.Default.frmReg.WindowState == FormWindowState.Minimized)
{
Properties.Settings.Default.frmReg.WindowState = FormWindowState.Normal ;
}
else
{
Properties.Settings.Default.frmReg.Focus();
}
}

Code to close the opened form:
Properties.Settings.Default.frmReg = null;

testing post

testing post

Thursday, October 26, 2006

using OleDbCommand class to update a database table based on one or more variable values C#.net 2005 winform app

using ( OleDbConnection connection = new OleDbConnection( Properties.Settings.Default.HPMConnectionString ) )
{
connection.Open();
OleDbCommand changeActiveToNoCommand = new OleDbCommand( "UPDATE staff SET active = no WHERE staff_id = @staff_id" , connection );
changeActiveToNoCommand.Parameters.AddWithValue( "@staff_id" , Convert.ToInt64( staff_id ) );
changeActiveToNoCommand.ExecuteNonQuery();
}

using OleDbDataReader class to retrieve a value based on one or more variable values C#.net 2005 winform app

string staff_no = staffDataGridView.CurrentRow.Cells[0].Value.ToString();

string staff_id="";

using (OleDbConnection connection = new OleDbConnection(Properties.Settings.Default.HPMConnectionString))
{
//OleDbCommand findStaffIDCommand = new OleDbCommand("SELECT staff_id FROM staff WHERE staff_no = '" + staff_no + "'", connection);
OleDbCommand findStaffIDCommand = new OleDbCommand( "SELECT staff_id FROM staff WHERE staff_no = @staff_no",connection );
findStaffIDCommand.Parameters.AddWithValue( "@staff_no" , staff_no );

connection.Open();
OleDbDataReader reader = findStaffIDCommand.ExecuteReader();

while (reader.Read())
{
staff_id = (reader[0].ToString());
}
reader.Close();
}
MessageBox.Show( staff_id.ToString() );

Wednesday, October 25, 2006

dataGridView show value of any cell on selected row (multiRow select = false) C#.net 2005

MessageBox.Show(clientsDataGridView.CurrentRow.Cells[0].Value + "");

Tuesday, October 24, 2006

tooltip in VS2005 winform and asp applications

in winform applications, there is a component called "tooltip", which can be referenced by other visual components

in asp.net applications, there is a property called "tooltip" for most of the visual components, which can be used to enter single line tooltipss.
There is a third party tooltip utility called "cooltip", which is much more powerful:
http://www.acooltip.com/index.html#

Sunday, October 22, 2006

make combobox readonly in C#.net 2005 winform application

change the value of property "DropDownStyle" to "DropDownList)

referencing other classes C#.NET 2005

if you create a class within a subfolder of a winform project, you can't reference it within he code of a class in the root folder of project.
Solution:
to create the class in the same folder/rootlevel as the class that needs to have referencing code, and then move the class into anyother folder

access application settings in code C#.NET 2005

to access the values predefined in application settings, do this:
label1.Text = Properties.Settings.Default.aaa;
aaa is the name of the variable;

to persist the change, do this:
Properties.Settings.Default.aaa = "bbb";
Properties.Settings.Default.Save();