我在处理发送短信的应用程序中使用 JTextArea 对象。
我使用了 DocumentFilter 以允许在文本区域中仅键入 160 个字符,但现在,我希望文本区域的大小保持不变。如果我继续在同一行上书写而不按“回车”键,甚至当我继续只按 Enter 键时,它会继续增加。我也尝试过使用“滚动条”,但问题仍然存在。给我一些建议。下面是我的代码。请检查。
class Send_sms extends JPanel implements ActionListener,DocumentListener
{
JButton send;
JTextArea smst;
JLabel title,limit;
JPanel mainp,titlep,sendp,wrap,titlewrap,blankp1,blankp2,sendwrap;
JScrollPane scroll;
Border br,blackbr;
Boolean flag = false;
PlainDocument plane;
public static final int LINES = 4;
public static final int CHAR_PER_LINE = 40;
//character limit 160 for a sms
public Send_sms()
{
br = BorderFactory.createLineBorder(Color.RED);
blackbr = BorderFactory.createEtchedBorder(EtchedBorder.RAISED,Color.DARK_GRAY,Color.GRAY);
setBorder(blackbr);
title = new JLabel("Enter the text you want to send!");
title.setFont(new Font("",Font.BOLD,17));
limit = new JLabel(""+charCount+" Characters");
smst = new JTextArea(LINES,CHAR_PER_LINE);
smst.setSize(100,100);
plane = (PlainDocument)smst.getDocument();
//adding DocumentSizeFilter 2 keep track of characters entered
plane.setDocumentFilter(new DocumentSizeFilter(charCount));
plane.addDocumentListener(this);
send = new JButton("Send");
send.setToolTipText("Click Here To Send SMS");
send.addActionListener(this);
//scroll = new JScrollPane(smst);
//scroll.setPreferredSize(new Dimension(200,200));
//scroll.setVerticalScrollBarPolicy(null);
//scroll.setHorizontalScrollBarPolicy(null);
smst.setBorder(br);
blankp1 = new JPanel();
blankp2 = new JPanel();
titlep = new JPanel(new FlowLayout(FlowLayout.CENTER));
titlewrap = new JPanel(new GridLayout(2,1));
mainp = new JPanel(new BorderLayout());
sendwrap = new JPanel(new GridLayout(3,1));
sendp = new JPanel(new FlowLayout(FlowLayout.CENTER));
wrap = new JPanel(new BorderLayout());
titlep.add(title);
titlewrap.add(titlep);
titlewrap.add(blankp1);
sendp.add(send);
sendwrap.add(limit);
sendwrap.add(blankp2);
sendwrap.add(sendp);
wrap.add(smst,BorderLayout.CENTER);
mainp.add(titlewrap,BorderLayout.NORTH);
mainp.add(wrap,BorderLayout.CENTER);
mainp.add(sendwrap,BorderLayout.SOUTH);
add(mainp);
}
public void actionPerformed(ActionEvent e)
{
Vector<Vector<String>> info = new Vector<Vector<String>> ();
Vector<String> numbers = new Vector<String>();
if(e.getSource() == send)
{
//Call a function to send he message to all the clients using text
//charCount = 165;
String msg = smst.getText();
if(msg.length() == 0)
JOptionPane.showMessageDialog(null,"Please Enter Message","Error",JOptionPane.ERROR_MESSAGE);
else
{
// System.out.println("Message:"+msg);
Viewdata frame = new Viewdata(msg);
limit.setText(""+charCount+" Characters");
charCount = 160;
}
}
}
public void insertUpdate(DocumentEvent e)
{
System.out.println("The legth:(insert) "+e.getLength());
for(int i = 0;i<e.getLength(); i++)
{
if(charCount >0)
charCount--;
else
break;
}
limit.setText(""+charCount+" Characters");
}
public void removeUpdate(DocumentEvent e)
{
//System.out.println("The legth(remove): "+e.getLength());
for(int i = 0;i<e.getLength(); i++)
{
charCount++;
}
limit.setText(""+charCount+" Characters");
}
public void changedUpdate(DocumentEvent e)
{
//System.out.println("The legth(change): "+e.getLength());
}
}//end Send_sms
最佳答案
听起来像是您正在使用
创建文本区域JTextArea textArea = new JTextArea();
当使用这种格式时,文本区域没有首选大小,因此它会不断增长。如果您使用:
JTextArea textArea = new JTextArea(2, 30);
JScrollPane scrollPane = new JScrollPane( textArea );
那么文本区域的首选大小将是 2 行和(大约)30 列。当您输入超过首选宽度时,将出现水平滚动条。或者,如果您打开换行,则文本将换行并出现一个垂直滚动条。
关于java - 如何保持 JTextArea 的大小不变?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/2454501/