[英]Revalidate and repaint - Java 6
我正在嘗試編譯我的Java類文件,但是由於學校計算機上的Java很舊(Java 6)而無法運行,而在我自己的筆記本電腦上它卻可以工作(Java 7)
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JFrame;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.JPanel;
public class GUI extends JFrame {
private Rainfall rainfall;
/**
* Creates new form GUI
*/
public GUI(String fileName) {
rainfall = new Rainfall(fileName); //Initialise rainfall data
this.setTitle("Rainfall Analysis"); //Define the title
this.setSize(750, 650); //Define the size of the window
this.setResizable(false); //Disable resizability
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
//Definition of the menu
JMenuBar menuBar = new JMenuBar(); // Initialisation of the first menu bar
JMenu menuA = new JMenu("Rainfall Information"); // Build first menu
// A group of JMenuItems
JMenuItem menuItemA1 = new JMenuItem("Global Information"); // Create a menu item containing "Global Information" as text
JMenuItem menuItemA2 = new JMenuItem("Month Calendar Based Information");
JMenuItem menuItemA3 = new JMenuItem("Month Graphical Based Information");
menuA.add(menuItemA1);
menuA.addSeparator(); // We add a seperator to seperate the menu items
menuA.add(menuItemA2);
menuA.addSeparator();
menuA.add(menuItemA3);
JMenu menuB = new JMenu("Rainfall Analysis"); // Initialisation of the second menu bar
JMenuItem menuItemB1 = new JMenuItem("Yearly statistics"); // Create a menu item containing "Yearly Statistics" as text
JMenuItem menuItemB2 = new JMenuItem("Comparison between two months' rainfall"); // Create a menu item
menuB.add(menuItemB1); // Add menuItem to the menu(menuB)
menuB.addSeparator(); // We add a seperator to seperate the menu items
menuB.add(menuItemB2);
//Associate events to menu items
menuItemA1.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent ae) {
setContentPane(new RecordsView(rainfall)); //Make RecordsView as the content panel
getContentPane().revalidate();
getContentPane().repaint();
}
});
menuItemA2.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent ae) {
setContentPane(new MonthCalendarView(rainfall));//Make MonthCalendarView as the content panel
getContentPane().revalidate();
getContentPane().repaint();
}
});
menuItemA3.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent ae) {
setContentPane(new MonthGraphicalView(rainfall));//Make MonthGraphicalView as the content panel
getContentPane().revalidate();
getContentPane().repaint();
}
});
menuItemB1.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent ae) {
JPanel p = new JPanel();
p.setSize(750, 650);
setContentPane(p);
getContentPane().add(rainfall.getGlobalChartByYears()); //Make Chart that show statistics over years as the content panel
getContentPane().revalidate();
getContentPane().repaint();
}
});
menuItemB2.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent ae) {
setContentPane(new ComparisonView(rainfall)); // Set the comparisonView as the content of content pane so that it will be displayed in the GUI
getContentPane().revalidate();
getContentPane().repaint();
}
});
menuBar.add(menuA); // Add menuA to menuBar
menuBar.add(menuB); // Add menuB to menuBar
//End menu
this.setJMenuBar(menuBar); // Set the menu bar (menuBar) as the menu bar of the container
this.setContentPane(new RecordsView(rainfall));
}
/**
* @param args the command line arguments
*/
public static void main(final String args[]) {
/* Create and display the form */
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new GUI(args.length==0?"2RainfallDataLanc.txt":args[0]).setVisible(true);
}
});
}
}
編譯時收到錯誤:
GUI.java:90: cannot find symbol
symbol : method revalidate()
location: class java.awt.Container
getContentPane().revalidate();
^
java版本是:版本6更新45
鑒於我在編寫項目時一直在研究版本7。
看來Java的6版本無法識別重新驗證。
我嘗試使用了invalidate,因為環顧四周invalidate用於Java 6。
我的問題(很抱歉在開始時未添加); 我將如何使用Java 6進行編譯?
謝謝
作為解決方法,您可以執行
invalidate();
validate();
這近似於在沒有RootPane
遞歸的情況下在revalidate中發生的情況。
另一個選擇是如果窗口大小未更改,則調用pack 。
盡管升級到Java 7會更簡單
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