DHBW Karlsruhe, Angewandte Informatik Programmieren in JAVA W. Geiger, T. Schlachter, C. Schmitt, W.

Transkript

1 Bereich: Grafische Benutzeroberflächen (UI), Events (1) Währungsumrechner (2) Package: de.dhbwka.java.exercise.ui.event Musterlösung Klasse: CurrencyCalculator package de.dhbwka.java.exercise.ui.event; import java.awt.borderlayout; import java.awt.event.actionevent; import java.awt.event.actionlistener; import javax.swing.jbutton; import javax.swing.jframe; import javax.swing.jtextfield; DHBW 1.0 Part of lectures on 'Programming in Java'. Baden-Wuerttemberg Cooperative State University. (C) 2016 by W. Geiger, T. Schlachter, C. Schmitt, W. Suess / public class CurrencyCalculator implements ActionListener { public final float CHANGE_RATE = 1.14f; private JFrame f = new JFrame("Währungsumrechner");; private JTextField input = new JTextField( "Bitte hier Betrag zum Umrechnen eingeben!"); private JButton eur2usdbt = new JButton("EUR -> USD"); private JButton usd2eurbt = new JButton("USD -> EUR"); private JButton cancelbt = new JButton("Abbrechen"); public CurrencyCalculator() { f.setdefaultcloseoperation(jframe.exit_on_close); f.setlayout(new BorderLayout(10, 10)); // Add ActionsListeners (2nd Part) eur2usdbt.addactionlistener(this); usd2eurbt.addactionlistener(this); cancelbt.addactionlistener(this); f.add(input, BorderLayout.NORTH); f.add(eur2usdbt, BorderLayout.WEST); f.add(usd2eurbt,borderlayout.center); f.add(cancelbt, BorderLayout.EAST); f.setsize(350, 90); f.setvisible(true); // Fortsetzung nächste Seite!

2 / Eventhandling (2nd Part) / public void actionperformed(actionevent e) { if (e.getsource() == cancelbt) // Abbruch gedrueckt System.exit(0); float amount = 0.0f; amount = Float.parseFloat(input.getText()); if (e.getsource() == eur2usdbt) amount = amount CHANGE_RATE; if (e.getsource() == usd2eurbt) amount = amount / CHANGE_RATE; input.settext(string.valueof(amount)); catch (Exception ex) { input.settext("fehler beim Parsen des Betrags."); public static void main(string[] args) { new CurrencyCalculator();

3 Grafische Benutzeroberflächen (UI), Events (1) Body-Mass-Index (BMI) Package: de.dhbwka.java.exercise.ui.event Musterlösung Klasse: BMICalculator package de.dhbwka.java.exercise.ui.event; import java.awt.gridlayout; import java.awt.event.actionevent; import java.awt.event.actionlistener; import javax.swing.buttongroup; import javax.swing.jbutton; import javax.swing.jframe; import javax.swing.jlabel; import javax.swing.jpanel; import javax.swing.jradiobutton; import javax.swing.jtextfield; DHBW 1.0 Part of lectures on 'Programming in Java'. Baden-Wuerttemberg Cooperative State University. (C) 2016 by W. Geiger, T. Schlachter, C. Schmitt, W. Suess / public class BMICalculator implements ActionListener { private JFrame frame; private JTextField weightfield = new JTextField(10); private JTextField heightfield = new JTextField(10); private JTextField bmifield = new JTextField(15); private JTextField messagefield = new JTextField(20); private JRadioButton rbmale = new JRadioButton("männlich", true); private JRadioButton rbfemale = new JRadioButton("weiblich", false); public BMICalculator() { frame = new JFrame("BMI Calculator"); frame.setlayout(new GridLayout(6,1)); JPanel weightpanel = new JPanel(); JPanel heightpanel = new JPanel(); JPanel sexpanel = new JPanel(); JPanel calcbtnpanel = new JPanel(); JPanel bmipanel = new JPanel(); JPanel messagepanel = new JPanel(); ButtonGroup g = new ButtonGroup(); g.add(rbmale); g.add(rbfemale); weightpanel.add(new JLabel("Gewicht in kg:")); weightpanel.add(weightfield); heightpanel.add(new JLabel("Groesse in m:")); heightpanel.add(heightfield); sexpanel.add(rbmale);

4 sexpanel.add(rbfemale); JButton calcbtn = new JButton("berechne"); calcbtn.addactionlistener(this); calcbtnpanel.add(calcbtn); bmipanel.add(new JLabel("BMI:")); bmipanel.add(bmifield); messagepanel.add(messagefield); frame.add(weightpanel); frame.add(heightpanel); frame.add(sexpanel); frame.add(calcbtnpanel); frame.add(bmipanel); frame.add(messagepanel); frame.setdefaultcloseoperation(jframe.exit_on_close); frame.pack(); frame.setvisible(true); public void actionperformed(actionevent e) { int weight = Integer.parseInt(weightField.getText()); double height = Double.parseDouble(heightField.getText()); double bmi = weight/(heightheight); bmifield.settext(string.valueof(bmi)); messagefield.settext(getbmitype(rbmale.isselected(),bmi)); catch (Exception ex) { bmifield.settext("falsche Eingabe"); public String getbmitype(boolean male, double bmi){ String erg; if (male) { if (bmi<20) erg="untergewicht"; else if (bmi<25) erg="normalgewicht"; else if (bmi<30) erg="uebergewicht"; else if (bmi<40) erg="adipositas"; else erg="massive Adipositas"; else { if (bmi<19) erg="untergewicht"; else if (bmi<24) erg="normalgewicht"; else if (bmi<30) erg="uebergewicht"; else if (bmi<40) erg="adipositas"; else erg="massive Adipositas"; return erg; public static void main(string[] args) { new BMICalculator();

5 Grafische Benutzeroberflächen (UI), Events (1) Zahlenraten (2) Package: de.dhbwka.java.exercise.ui.event Musterlösung Klasse: NumberGuess package de.dhbwka.java.exercise.ui.event; import java.io.; import java.util.; import java.awt.; import java.awt.event.; import javax.swing.; DHBW 1.0 Part of lectures on 'Programming in Java'. Baden-Wuerttemberg Cooperative State University. (C) 2016 by W. Geiger, T. Schlachter, C. Schmitt, W. Suess / public class NumberGuess extends JFrame { int ratezahl, tipp, versuche; int limit = 1000; JButton exit, ok, neu, stat; JPanel p1, p2, p3, p4; JTextField sp; JTextField ein; JTextField aus; String ergfile = "erg.txt"; NumberGuess() { p4 = new JPanel(); p1 = new JPanel(); p2 = new JPanel(); p3 = new JPanel(); neu = new JButton("Neues Spiel"); ok = new JButton("OK"); exit = new JButton("Exit"); stat = new JButton("Bester"); JLabel s = new JLabel("Spielername"); JLabel l = new JLabel("Zahl zwischen 1 und " + limit + " eingeben"); sp = new JTextField("Name", 20); ein = new JTextField(10); aus = new JTextField(40); p4.add(s); p4.add(sp); p1.add(l); p1.add(ein); p2.add(neu); p2.add(ok); p2.add(stat); p2.add(exit);

6 p3.add(aus); setlayout(new GridLayout(4, 1)); add(p4); add(p1); add(p2); add(p3); eventhandling(); erzeugezahl(); settitle("ratespiel"); setsize(500, 250); setdefaultcloseoperation(jframe.exit_on_close); setvisible(true); public void eventhandling() { neu.addactionlistener(new ActionListener() { erzeugezahl(); ); exit.addactionlistener(new ActionListener() { System.exit(0); ); ein.addactionlistener(new ActionListener() { okactionlistener(event); ); ok.addactionlistener(new ActionListener() { okactionlistener(event); ); stat.addactionlistener(new ActionListener() { bester(); ); public void okactionlistener(actionevent event) { tipp = Integer.parseInt(ein.getText()); versuche++; ein.settext(""); if (tipp > ratezahl) {

7 aus.settext(" Versuch Nr. " + versuche + ": " + tipp + " zu hoch!"); else if (tipp < ratezahl) { aus.settext("versuch Nr. " + versuche + ": " + tipp + " zu niedrig!"); else { aus.settext("versuch Nr. " + versuche + ": Sie haben die Zahl erraten!!! Neues Spiel!"); schreibefile(); erzeugezahl(); catch (NumberFormatException ee) { aus.settext("falsche Eingabe"); private void schreibefile() { FileWriter f = new FileWriter(ergfile, true); String name = sp.gettext(); f.write(name + " " + versuche + " Versuche\n"); f.close(); catch (Exception e) { private void bester() { int max = 1000; String name = ""; BufferedReader in = new BufferedReader(new FileReader(ergfile)); String line; do { line = in.readline(); if (line!= null) { StringTokenizer st = new StringTokenizer(line); String help = st.nexttoken(); int hilf = Integer.parseInt(st.nextToken()); if (hilf < max) { name = new String(help); max = hilf; catch (Exception e) { catch (IOException e) { line = null; while (line!= null); in.close(); aus.settext("bisher Bester: " + name + ", " + max + " Versuche"); catch (Exception eee) {

8 private void erzeugezahl() { ein.settext(""); aus.settext("neues Spiel!"); ratezahl = (int) (Math.random() limit + 1); System.out.println("Zu erratende Zahl: " + ratezahl); versuche = 0; public static void main(string args[]) { new NumberGuess();