最近我用JAVA / Swing编写了一对带有简单GUI的应用程序:
他们看起来很好,他们工作正常。直到我在Windows 7平板电脑(HP Slate)上执行。它们看起来都是空的,中间有一个小符号。此图显示了第一个应用程序(JTextArea one)在平板电脑上的显示效果:
这里有什么问题,如何解决?
我正在显示代码,但由于在使用计算机时看起来很好,我想这不是问题所在:
import java.io.*;
import java.net.*;
import java.util.Date;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.awt.GridBagLayout;
import java.awt.GridBagConstraints;
import java.awt.Dimension;
import java.awt.Toolkit;
import javax.swing.JFrame;
import javax.swing.JTextArea;
import javax.swing.JOptionPane;
import javax.swing.JScrollPane;
import javax.swing.text.DefaultCaret;
class EstacionBase extends JFrame{
private static final long serialVersionUID = 1L;
private static final String logFile = "log.txt";
private DateFormat df;
private FileWriter logWriter;
private Socket sisnetSocket;
private ServerSocket serverSocket;
private Socket clientSocket;
private BufferedWriter outToPlane;
private BufferedWriter outToDataServer;
private BufferedReader inputFromDataServer;
private JTextArea console;
private boolean terminated;
public EstacionBase() {
setTitle("Base station");
createGUI();
pack();
setResizable(false);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setLocationRelativeTo(null);
setVisible(true);
try{
df = new SimpleDateFormat ("[hh:mm:ss]");
logWriter = new FileWriter(System.getProperty("user.dir") + "\\" + logFile, true);
serverSocket = new ServerSocket(PORT); // A socket I use for listening for connections
} catch(IOException e){
JOptionPane.showMessageDialog(this, e.getMessage(), "Error", JOptionPane.ERROR_MESSAGE);
}
//mainLoop(); // doing some stuff
try{
logWriter.close();
serverSocket.close();
} catch(IOException e){
JOptionPane.showMessageDialog(this, e.getMessage(), "Error", JOptionPane.ERROR_MESSAGE);
}
}
private void createGUI() {
setLayout(new GridBagLayout());
GridBagConstraints c = new GridBagConstraints();
c.gridx = 0;
c.gridy = 0;
c.fill = GridBagConstraints.BOTH;
console = new JTextArea(40, 80);
JScrollPane scroll = new JScrollPane(console);
DefaultCaret caret = (DefaultCaret) console.getCaret();
caret.setUpdatePolicy(DefaultCaret.ALWAYS_UPDATE); // Autoscroll
console.setText("Welcome to base station");
console.setEditable(false);
console.setVisible(true);
add(scroll, c);
}
private void writeToConsole(String msg) throws IOException{
Date now = new Date();
String timeStr = df.format(now);
console.append("\n");
console.append(timeStr + " " + msg);
writeToLogFile(msg, timeStr);
}
private void writeToLogFile(String msg, String timeStr) throws IOException{
logWriter.write(timeStr + " " + msg + CRLF);
logWriter.flush();
}
public static void main(String[] arg) {
EstacionBase frame = new EstacionBase();
}
}
答案 0 :(得分:2)
这是一个GridBagLayout
问题;我不确定最佳修复方法,但它可以使用默认的JFrame
布局BorderLayout.CENTER
。从功能上讲,这三种布局具有类似的效果:
BorderLayout.CENTER
:JFrame#add()
的默认设置。
GridLayout()
:一列,一行,无间隙。
GridBagLayout()
:默认GridBagConstraints()
将所有字段设置为默认值。
另外,应该在event dispatch thread上构建和操作仅的Swing GUI对象。