Lecture 6:

Advanced GUI Controls

Up to now we have used simple controls such as buttons and textboxes. Now we will review some interactive (e.g. dialog) controls available to the C# applications developer.

OpenFileDialog and SaveFileDialog and the associated controls interact with the user to determine the location and name of a file to read or write. These common dialogs are not for the purpose of actually reading or writing files.

Other advanced controls we will cover here include MessageBoxes with decisions, the Calender, ListBoxes, ComboBoxes, and TabControls.

In addition, we continue to review methods for reading and writing text files using StreamReader and StreamWriter.

This will be our first look at Multiple Document Interfaces (MDI's). The demo program WidgetDemo is an example of an MDI program that also happens to illustrate the use of several GUI controls.

Topics

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array.txt

Reading a Textfile

In the example code ReadTextArray a 10x10 array of integers named array.txt is read and loaded into a two-dimensional array.

string fname = ""; string textline = ""; fname = txtFilename.Text; int j; try { TextReader tr = new StreamReader(fname); n = Convert.ToInt32(tr.ReadLine()); txtDisplay.Text = Convert.ToString(n) + "\r\n"; W = new int[n,n]; for (int i = 0; i < n; i++) { textline = tr.ReadLine(); txtDisplay.Text = txtDisplay.Text + " " + textline + "\r\n"; j = 0; foreach (string subString in textline.Split(' ')) { if (subString != "") { W[i,j] = Int32.Parse(subString); j += 1; } } } tr.Close(); } catch { txtFilename.Text = "no such file"; }

Reading an Array of Integers

private void btnCompute_Click(object sender, EventArgs e) { int sum; string str = ""; txtDisplay.Text = ""; txtDisplay.Text += "\r\n"; for (int i=0; i < n; i++) { sum = 0; for (int j=0; j < n; j++) { sum += W[i, j]; } str += "Row " + Convert.ToString(i) + " = " + Convert.ToString(sum) + "\r\n"; } txtDisplay.Text += str; }

Using the Array

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array.txt

The Benefit of Checking for Empty String

using System.IO;::

private void OnFileOpen(object sender, EventArgs e) { OpenFileDialog dialog = new OpenFileDialog(); dialog.Filter = "text files (*.txt)|*.txt"; dialog.ShowDialog(); filename = dialog.FileName; OpenFile(); }

private void OnFileSaveAs(object sender, EventArgs e) { if (dlgSaveFile.ShowDialog() == DialogResult.OK) { filename = dlgSaveFile.FileName; SaveFile(); } }

The Purpose of Common File Dialogs:to retreive a path and filename

try { printDocument.Print(); } catch (InvalidPrinterException ex) { MessageBox.Show(ex.Message, "Print Ticket", MessageBoxButtons.OK, MessageBoxIcon.Error); }

::

private void printDocument_PrintPage(object sender, PrintPageEventArgs e) { Bitmap center = new Bitmap("ticket_header_center.jpg"); string line = "";

line = txtFirst.Text + " " + txtLast.Text; e.Graphics.DrawString(line, new Font("Arial", 12),Brushes.Black, 20, 240); line = txtStreet.Text; e.Graphics.DrawString(line, new Font("Arial", 12), Brushes.Black, 20, 260); line = txtCity.Text + ", " + txtState.Text + " " + txtZip.Text; e.Graphics.DrawString(line, new Font("Arial", 12), Brushes.Black, 20, 280); e.Graphics.DrawImage(center,275, 20); }

Printing a Document with Images and Text

The Toolbox Widget Demo

The Widget Demo is an example of an MDI application

Each demo is presented as a Child Form under the Widget menu.

a new mouseChild form is created here and isdisplayed inside the widgetMain form.

establishes widgetMain as the MdiParent of mouseChild

Mouse Demo

private Point mpt;

public mouseChild(WidgetDemo.widgetMain parent){ InitializeComponent(); this.MdiParent = parent;}

private void mouseChild_MouseMove(object sender, MouseEventArgs e){ Point lpt = new Point(); mpt = MousePosition; tbxXpos.Text = Convert.ToString(mpt.X); tbxYpos.Text = Convert.ToString(mpt.Y); Form mschild = this.ActiveMdiChild; lpt = this.Location; tbxrelXpos.Text = Convert.ToString(mpt.X - lpt.X - 6); tbxrelYpos.Text = Convert.ToString(mpt.Y - lpt.Y - 74);}

private void mouseChild_MouseDown(object sender, MouseEventArgs e){ MessageBox.Show(Convert.ToString(e.Button) + " button Pressed");}

public partial class msgBoxChild : Form{ private MessageBoxButtons buttonType = MessageBoxButtons.OK; private MessageBoxIcon iconType = MessageBoxIcon.Exclamation;

public msgBoxChild(WidgetDemo.widgetMain parent) { InitializeComponent(); this.MdiParent = parent; rbExclamation.Checked = true; rb_OK.Checked = true; }

private void btnDisplayMsgBox_Click(object sender, EventArgs e) { if (rb_OK.Checked) buttonType = MessageBoxButtons.OK; if (rb_OKCancel.Checked) buttonType = MessageBoxButtons.OKCancel; if (rb_AbortRetryIgnore.Checked) buttonType = MessageBoxButtons.AbortRetryIgnore;

::

if (rbQuestion.Checked) iconType = MessageBoxIcon.Question; if (rbStop.Checked) iconType = MessageBoxIcon.Stop; if (rbWarning.Checked) iconType = MessageBoxIcon.Warning; DialogResult result = MessageBox.Show("Your message goes here.", "Custom MessageBox", buttonType, iconType); }}

messageBox Demo

private void newToolStripButton_Click(object sender, EventArgs e){ picBox.Image = null; this.Width = 200; this.Height = 200;}

private void openToolStripButton_Click(object sender, EventArgs e){ int minWidth = 100; int minHeight = 50;

string fileName = ""; OpenFileDialog dlg = new OpenFileDialog(); if (dlg.ShowDialog() == DialogResult.OK) { fileName = dlg.FileName; Bitmap img = new Bitmap(fileName); picBox.Image = img; if (img.Width + 10 > minWidth) this.Width = img.Width + 10; else this.Width = minWidth; if (img.Height + 60 > minHeight) this.Height = img.Height + 60; else this.Height = minHeight; }}

pictureBox Demo

private DateTime dtobj = new DateTime();

public calChild(WidgetDemo.widgetMain parent){ InitializeComponent(); this.MdiParent = parent;}

private void monthCalendar_MouseUp(object sender, MouseEventArgs e){ dtobj = monthCalendar.SelectionStart; tbxDay.Text = Convert.ToString(dtobj.Day); tbxMonth.Text = Convert.ToString(dtobj.Month); tbxYear.Text = Convert.ToString(dtobj.Year); tbxDate.Text = Convert.ToString(dtobj.Date); tbxDayOfYear.Text = Convert.ToString(dtobj.DayOfYear); tbxDayOfWeek.Text = Convert.ToString(dtobj.DayOfWeek);}

monthCalendar Demo

private void linkLabel1_LinkClicked(object sender, LinkLabelLinkClickedEventArgs e){ linkLabel1.LinkVisited = true; System.Diagnostics.Process.Start(@"C:\");}

private void linkLabel2_LinkClicked(object sender, LinkLabelLinkClickedEventArgs e){ linkLabel2.LinkVisited = true; System.Diagnostics.Process.Start("notepad");}

private void linkLabel3_LinkClicked(object sender, LinkLabelLinkClickedEventArgs e){ linkLabel3.LinkVisited = true; System.Diagnostics.Process.Start("http://www.google.com");}

linkLabel Demo

private void listBoxFavs_MouseUp(object sender, MouseEventArgs e){ rtbxSelected.Text = ""; foreach (string item in listBoxFavs.SelectedItems) { rtbxSelected.Text += item + "\n"; }}

listBox Demo

comboBox Demo

private string[,] countrydata = new string[237, 3];

private void load_country_data(){ string textline; int colnum; int rownum = 0;

StreamReader tr = new StreamReader("country_data.txt"); do { textline = tr.ReadLine(); colnum = 0; foreach (string str in textline.Split('\t')) { if (str != "xxx") { countrydata[rownum, colnum] = str; colnum += 1; } else break; } rownum += 1; } while (textline != "xxx"); tr.Close();}public comboChild(WidgetDemo.widgetMain parent){ InitializeComponent(); this.MdiParent = parent; load_country_data(); comboCountryList.Text = "Select a Country";}

Reading the country_data File

private void comboCountryList_SelectedIndexChanged(object sender, EventArgs e){ int index = -1; try { index = comboCountryList.SelectedIndex; rtbDisplay.Text = "Selected index = " + Convert.ToString(index) + "\n"; rtbDisplay.Text += "Population = " + countrydata[index,2] + "\n"; rtbDisplay.Text += "Rank by Population = " + countrydata[index,1] + "\n"; rtbDisplay.Text += "Gross Domestic Product = " + countrydata[index,0] + "\n"; } catch { comboCountryList.Text = "Select a Country"; }}

ComboBox SelectedIndexChange Event

tabControl Demo

public partial class tabChild : Form { private int[] face = new int[4] { 0, 0, 0, 0 }; private Bitmap[] head = new Bitmap[8]; private Bitmap[] eyes = new Bitmap[8]; private Bitmap[] nose = new Bitmap[8]; private Bitmap[] chin = new Bitmap[8]; private bool in_color = true;

public void load_images(){ string[] person = new string[] {"churchill", "eastwood", "henryVIII", "joker", "mona", "monroe", "rubens", "vangogh"}; string filename;

for (int i = 0; i < 8; i++) { filename = person[i] + "_01.jpg"; head[i] = new Bitmap(filename); filename = person[i] + "_02.jpg"; eyes[i] = new Bitmap(filename); filename = person[i] + "_03.jpg"; nose[i] = new Bitmap(filename); filename = person[i] + "_04.jpg"; chin[i] = new Bitmap(filename); }}

tabControl Demo Image Load

public void show_face(){ if (in_color) { picBoxHead.Image = head[face[0]]; picBoxEyes.Image = eyes[face[1]]; picBoxNose.Image = nose[face[2]]; picBoxChin.Image = chin[face[3]]; } else { Bitmap img0 = new Bitmap(head[face[0]]); Grayscale(ref img0); picBoxHead.Image = img0; Bitmap img1 = new Bitmap(eyes[face[1]]); Grayscale(ref img1); picBoxEyes.Image = img1; Bitmap img2 = new Bitmap(nose[face[2]]); Grayscale(ref img2); picBoxNose.Image = img2; Bitmap img3 = new Bitmap(chin[face[3]]); Grayscale(ref img3); picBoxChin.Image = img3; }}

tabControl Demo show_face( )

private void btnDisplay_Click(object sender, EventArgs e) { if (rbChurchill_01.Checked) face[0] = 0; if (rbEastwood_01.Checked) face[0] = 1; if (rbHenry_01.Checked) face[0] = 2; if (rbJoker_01.Checked) face[0] = 3; if (rbMona_01.Checked) face[0] = 4; if (rbMonroe_01.Checked) face[0] = 5; if (rbRubens_01.Checked) face[0] = 6; if (rbVanGogh_01.Checked) face[0] = 7; if (rbChurchill_02.Checked) face[1] = 0; if (rbEastwood_02.Checked) face[1] = 1; if (rbHenry_02.Checked) face[1] = 2; if (rbJoker_02.Checked) face[1] = 3; if (rbMona_02.Checked) face[1] = 4; if (rbMonroe_02.Checked) face[1] = 5; if (rbRubens_02.Checked) face[1] = 6; if (rbVanGogh_02.Checked) face[1] = 7; if (rbChurchill_03.Checked) face[2] = 0; if (rbEastwood_03.Checked) face[2] = 1; if (rbHenry_03.Checked) face[2] = 2; if (rbJoker_03.Checked) face[2] = 3; if (rbMona_03.Checked) face[2] = 4; if (rbMonroe_03.Checked) face[2] = 5; if (rbRubens_03.Checked) face[2] = 6; if (rbVanGogh_03.Checked) face[2] = 7; if (rbChurchill_04.Checked) face[3] = 0; if (rbEastwood_04.Checked) face[3] = 1; if (rbHenry_04.Checked) face[3] = 2; if (rbJoker_04.Checked) face[3] = 3; if (rbMona_04.Checked) face[3] = 4; if (rbMonroe_04.Checked) face[3] = 5; if (rbRubens_04.Checked) face[3] = 6; if (rbVanGogh_04.Checked) face[3] = 7; show_face(); }

There is a better way todeal with large numbersof Widget properties...

for example,

How would you create anarray of radioButtons?

Selecting face for Display

public partial class gdiChild : Form { protected override void OnPaint(PaintEventArgs e) { Graphics g = e.Graphics; Random rnd = new Random(); Pen MyPen = new Pen(Color.Red); Point a = new Point(50, 50); Point b = new Point(250, 250); for (int i = 0; i < 100; i++) { a.X = rnd.Next(10, this.Width - 30); a.Y = rnd.Next(10, this.Height - 60); b.X = rnd.Next(10, this.Width - 30); b.Y = rnd.Next(10, this.Height - 60); MyPen.Color = Color.FromArgb(rnd.Next(0, 255), rnd.Next(0, 255), rnd.Next(0, 255)); g.DrawLine(MyPen, a, b); } }

GDI+ Drawing Demo

onPaint is used for cleaning up windows aftermove and resize events...not for drawing

private void PaintThis() { Graphics g = pictureBox1.CreateGraphics(); Random rnd = new Random(); Pen MyPen = new Pen(Color.White); g.Clear(Color.White); Point a = new Point(50, 50); Point b = new Point(250, 250); for (int i = 0; i < 100; i++) { a.X = rnd.Next(10, this.Width - 30); a.Y = rnd.Next(10, this.Height - 60); b.X = rnd.Next(10, this.Width - 30); b.Y = rnd.Next(10, this.Height - 60); MyPen.Color = Color.FromArgb(rnd.Next(0, 255), rnd.Next(0, 255), rnd.Next(0, 255)); g.DrawLine(MyPen, a, b); }

gphChild Improves Drawing with GDI+

build your own methodsfor drawing. This method is calledwith a click-event for the picturebox

no auto-draw implemented