Java- AWT Applets-如何更改我的程序中形狀的大小?
該程序的設計目的是根據用戶設定的形狀,根據輸入改變其大小。
我有兩個問題。一個是用戶必須輸入它作爲一個字符串,但大小的值是一個整數。如果我將整數轉換爲字符串,轉換時會給我一個空例外。 (java.lang.Integer.parseInt(Unknown Source)Exception)。)
另一個問題是我不知道要在actionPerfomed方法中添加什麼。由於所有的信息只需要使用paint方法。我如何將整數值傳輸到Paint方法中。
import java.io.*;
import java.util.*;
import java.text.*;
import java.awt.*;
import java.awt.event.*;
import java.applet.*;
import java.applet.Applet;
public class ChangeSize extends Applet
implements ActionListener
{
Button bttn1 = new Button ("Circle");
Button bttn2 = new Button ("Square");
Button bttn3 = new Button ("Triangle");
Button bttn4 = new Button ("Rectangle");
Label lab1; // text within applet
TextField t1; // where user inputs text
String input;
int choice;
public void init()
{
this.setSize (500, 300);
setBackground (Color.lightGray);
lab1 = new Label ("Insert the size of the shape:");
//int Size = Integer.parseInt (input);
add (lab1);
t1 = new TextField();
add (t1);
bttn1.addActionListener (this); // circle button
bttn2.addActionListener (this); // square button
bttn3.addActionListener (this); // triangle button
bttn4.addActionListener (this); // rectangle button
add (bttn1);
add (bttn2);
add (bttn3);
add (bttn4);
}
public void paint (Graphics g)
{
int xpoints[] = {25, 145, 25, 145, 25}; \
int ypoints[] = {25, 25, 145, 145, 25};
int npoints = 5;
switch (choice)
{
case 1:
if (choice == 1)
g.setColor (Color.red);
g.fillOval (30, 40, 20, 20); // I want it to be (30,40, 20, size). Instead
case 2:
if (choice == 2)
g.fillRect (20, 40, 100, 100);
case 3:
if (choice == 3)
g.fillPolygon (xpoints, ypoints, npoints);
case 4:
if (choice == 4)
g.fillRect (20, 40, 50, 100);
break;
}
showStatus ("Please seclect an option.");
}
public void actionPerformed (ActionEvent evt)
{
if (evt.getSource() == bttn1)
choice = 1;
else if (evt.getSource() == bttn2)
choice = 2;
else if (evt.getSource() == bttn3)
choice = 3;
else if (evt.getSource() == bttn4)
choice = 4;
Size = t1.getText();
// I dont know what to put here
repaint();
}
}
爲什麼在2013年AWT? Swing是第3個千年(開始時)使用的GUI工具包。 'this.setSize(500,300);'不要在applet中執行此操作(無論是Applet ***還是*** JApplet),大小設置爲HTML(可能由JavaScript編寫)。 – 2013-03-03 02:03:09