WinForms tips and tricks

WinForms vs. WPF
WinForms controls
Messaging in WinForms
Adding .mdf file to your project

WinForms vs. WPF

WPF is newer and Windows Forms is still a perfectly valid choice.

WPF uses XAML, an XML file that you can edit to edit control design and style.

In WPF the ListView control has DataSource (not the case of WinForms).

WPF may need more memory than WinForms but it should run faster as it uses DirectX controls.

WinForms uses common Windows controls. WinForms cannot design web apps. WinForms is good for developing default Windows style applications.

WinForms controls

Following controls will be covered:

ComboBox
ListBox … (todo)
ListView
DataGridView
TextBox … (todo)
Image … (todo)

ComboBox control

Number of objects in combobox:

comboBox.Items.Count

To add an item just with text and without a hidden (key) value:

comboBox1.Items.Add("text");

To remove a single selected item:

comboBox1.Items.RemoveAt(0);  
comboBox1.Items.Remove(comboBox1.SelectedItem);  
comboBox1.Items.Remove("Tokyo");  

To remove all items:

comboBox1.Items.Clear();

Problem with Items.Add() is you cannot add both Value and Text for a single combobox item unless you create your special class:

public class ComboboxItem
    {
        public string Text { get; set; }
        public object Value { get; set; }
 
        public override string ToString()
        {
            return Text;
        }
    }

However, the upper method may not be the simplest way to go since there is a way to fill combobox via DataSource where you provide the table as DataSource:

comboBox1.DataSource = dt; // DataTable
comboBox1.ValueMember = "id";
comboBox1.DisplayMember = "name";

In the previous example the table has columns id and name.

To read the selected value from combobox (both text and hidden key) you can use this code:

comboBox1.Text // selected text
comboBox1.SelectedValue // selected value

ListView control

ListView controls a table of data. Each row inside ListView is called ListViewItem.

Sweet code for list view control:

listView1.FullRowSelect = true;
listView1.MultiSelect = false;
listView1.GridLines = true;
listView1.BackColor = System.Drawing.Color.Orange;
listView1.ForeColor = System.Drawing.Color.Black;
 
// adding data to the list view
string query = "select * from Reader";
DataTable dt = DB.ExecuteQuery(query);
 
 
// adding each line separately
foreach (DataRow row in dt.Rows)
{
    Trace.WriteLine("row in foreach");
 
    // ListViewItem means the single row
    ListViewItem item = new ListViewItem(row[0].ToString());
    item.SubItems.Add(row[1].ToString());
    item.SubItems.Add(row[2].ToString());
    item.SubItems.Add(row[3].ToString());
    item.SubItems.Add(row[4].ToString());
    item.SubItems.Add(row[5].ToString());
    item.SubItems.Add(row[6].ToString());
    listView1.Items.Add(item);
}

Alternative adding a new ListViewItem:

string[] data = new string[7];
 
data[0] = tbxID.Text;
data[1] = tbxPIN.Text; // tbxSSN.Text
data[2] = tbxName.Text;
data[3] = tbxLastName.Text;
data[4] = tbxCity.Text;
data[5] = tbxAddress.Text;
data[6] = tbxPhone.Text;
 
ListViewItem lvItem = new ListViewItem(data);
listView1.Items.Add(lvItem);

DataGridView

Sweet code for DataGridView class:

dataGridView1.AutoSizeColumnsMode = DataGridViewAutoSizeColumnsMode.Fill;
dataGridView1.AllowUserToAddRows = false;
dataGridView1.AllowUserToDeleteRows = false;
dataGridView1.EditMode = DataGridViewEditMode.EditProgrammatically;
 
dataGridView1.MultiSelect = false;
dataGridView1.RowHeadersVisible = false;
dataGridView1.SelectionMode = DataGridViewSelectionMode.FullRowSelect;
 
dataGridView1.AutoSizeRowsMode = DataGridViewAutoSizeRowsMode.None;
dataGridView1.AllowUserToResizeRows = false;
 
string query = "select BookID as Cipher, UDK, ISBN, Name from Books";
dataGridView1.DataSource = DB.ExecuteQuery(query);
dataGridView1.ClearSelection();

You may notice now the DataGridView control looks the same as the default style for ListView control.

Check if anything is selected:

if (dataGridView1.SelectedCells.Count > 0)
{
   // do something with the selected row(s)
}

Get the index of currently selected row:

int index = dataGridView1.CurrentCell.RowIndex
index = dataGridView1.SelectedRows[0].Index;

Get selected row first cell value:

DataGridViewRow row = dg.CurrentRow;
string text = row.Cells[0].Value.ToString();

Alternative to the previous method:

int ind = dgv.CurrentRow.Index
string text = dgv.Rows[ind].Cells[0].Value.ToString;

Messaging in WinForms

MessageBox.Show("Message", "Title");
Trace.WriteLine("Message");

Trace is the best way to print something to the output. using System.Diagnostics; is needed when you use the Trace class.

Adding `.mdf` file to your project

MDF stands for Master Database File.

Few ways to navigate your data:

SQL Server Object Explorer
Server Explorer
Data Sources (SHIFT + ALT + D)

To add .mdf file to your solution:

Project > Add New Item > Service-based Database
Open Server Explorer and you will find new Database1.mdf file
Right click Tables and select New Query and then execute any SQL query from your SQL file

…

tags: winforms - controls - C# & category: csharp