我在下面发布了我的完整代码，所以你们可以对我想要的东西有充分的理解。单击“发送”时，文本字段将清除但尚未准备好输入。我必须点击输入。我希望它立即为输入做好准备，textfield.setText（“”）将无效。有任何想法吗？
package javaapplication2;
import java.util.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.geom.Ellipse2D;
import java.io.*;
import javax.swing.*;//class to use to create GUI's
import javax.swing.border.Border;
import javax.swing.plaf.FontUIResource;
/**
*
* @author Jordan Anthony Hangman with dictionary
*/
public class JavaApplication2 extends JFrame{
static JLabel[] labels = new JLabel[20];//labels for displaying words under 20 characters
static int counter = 0;
static int badguess = 0;//keeps track of wrong guesses
static String wordbank = " Letter Bank:";
static char[] guesses = new char[26];
static int nguesses = 0;
static int amountc = 0;
public JavaApplication2(){
}
public static void main(String[] args) throws FileNotFoundException, IOException {
//Loading images to use for hangman game
ImageIcon hanginit = new ImageIcon("hangmaninit.jpg");
ImageIcon hang1 = new ImageIcon("hangman1.jpg");
ImageIcon hang2 = new ImageIcon("hangman2.jpg");
ImageIcon hang3 = new ImageIcon("hangman3.jpg");
ImageIcon hang4 = new ImageIcon("hangman4.jpg");
ImageIcon hang5 = new ImageIcon("hangman5.jpg");
ImageIcon hang6 = new ImageIcon("hangman6.jpg");
//initializing array for index values
int wordcount = 10;
String[] words1 = new String[wordcount];
int[] wordssel = new int[10];
for (int j=0; j<10; j++){
wordssel[j] = -1;
}
//setting instructions
String Instructions = "To start the game, click on the new game button. You get 6 incorrect guesses for every word. Once you get 6 guesses, the game will end. Click the end game button to go back to the home page. If you want to play again, you can click New Game and you will be able to guess a different word. After every game, a message will appear to tell you how many words you have guesses correctly. When all the words are played, a dialog box will be shown that says Game Over. Exit this box to exit the game.";
//reading in the words
int number = 0;
try(BufferedReader br = new BufferedReader(new FileReader("words.txt")))
{
String line = br.readLine();
while(line != null){
words1[number] = line;
number++;
line = br.readLine();
}
}
//randomizes words
boolean flag = false;
int rand = 0;
int count = 0;
int wordcounter = 0;
while(!flag){
Random random = new Random();
rand = random.nextInt(wordcount);
count = 0;
for (int o=0; o<wordcount; o++){
if(wordssel[o] != rand){
count++;
}
}
if(count == wordcount){
wordssel[wordcounter] = rand;
wordcounter++;
}
if(wordcounter == wordcount){
flag = true;
}
}
String[] randwords = new String[10];
for(int o=0; o<10; o++){
randwords[wordssel[o]] = words1[o];
}
//initializing label
for(int i=0; i<20; i++){
labels[i] = new JLabel(" ");
labels[i].setFont(new Font("Serif", Font.BOLD, 30));
}
//initializing guessedchar array
for(int i=0; i<26; i++){
guesses[i] = ' ';
}
//value for window size
int xlim = 1200;
int ylim = 1200;
int xlim2 = 1600;
int ylim2 = 1600;
int xlim3 = 900;
int ylim3 = 600;
//value for x and y centers
int xcent = xlim/2 - 20;
int ycent = ylim/2;
int xcent2 = xlim2/2;
int ycent2 = ylim2/2 - 20;
int xcent3 = xlim3/2;
int ycent3 = ylim3/2 - 20;
//creating frames
JFrame frame1 = new JFrame("Hangman");//creates a new frame or window
frame1.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);// I thiunk exits when clicks on red x
frame1.setSize(xlim, ylim); //size of window in pixels
JFrame frame2 = new JFrame("Hangman");//creates a new frame or window
frame2.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);// I thiunk exits when clicks on red x
frame2.setSize(xlim2, ylim2); //size of window in pixels
JFrame frame3 = new JFrame();
frame3.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame3.setSize(xlim3, ylim3);
//change font size for label, button, and textfield
UIManager.put("Button.font", new FontUIResource(new Font("Dialog", Font.BOLD, 24)));
UIManager.put("Label.font", new FontUIResource(new Font("Dialog", Font.PLAIN, 24)));
UIManager.put("TextField.font", new FontUIResource(new Font("Dialog", Font.PLAIN, 24)));
UIManager.put("TextArea.font", new FontUIResource(new Font("Dialog", Font.PLAIN, 24)));
//creates buttons
JButton button1 = new JButton("New Game?");
button1.setBounds(xcent - 90, ycent - 165, 180, 130);//(xstart, ytop, width, height)
JButton button2 = new JButton("End Game?");
button2.setBounds(xcent - 90, ycent - 65, 180, 130);//(xstart, ytop, width, height)
JButton button3 = new JButton("Instructions");
button3.setBounds(xcent - 120, ycent, 240, 100);
JButton button4 = new JButton("Main Menu");
button4.setBounds(xcent - 100, ycent + 100, 200, 100);
//creating border
Border border = BorderFactory.createLineBorder(Color.BLACK, 4);
//creating labels
JLabel labelresult = new JLabel("");//label for win or losing game
labelresult.setBounds(400, 400, 400, 40);
JLabel labelhang = new JLabel();//label for hangman images
labelhang.setBounds(450, 375, 677, 620);
JLabel label3 = new JLabel("Hello");
label3.setBounds(200, 260, 500, 40);
JLabel label4 = new JLabel("Hello");
label4.setBounds(440, 1300, 800, 40);
JLabel label5 = new JLabel("Hello");
label5.setBounds(590, 1300, 800, 40);
JLabel label6 = new JLabel("Game Over");
label6.setBounds(380, 250, 200, 40);
JLabel lettersw = new JLabel();
JLabel label7 = new JLabel("How To Play");
label7.setBounds(500, 50, 200, 40);
JLabel label8 = new JLabel("Error");
label8.setBounds(590, 1300, 800, 40);
label8.setText("You can only enter one letter at a time.");
JLabel label9 = new JLabel("Error");
label9.setBounds(674, 1300, 800, 40);
label9.setText("You must enter a letter");
JLabel label10 = new JLabel(wordbank);
label10.setBounds(xcent2 - 200, 220, 400, 40);
JLabel label11 = new JLabel("You have already entered this letter.");
label11.setBounds(608, 1300, 800, 40);
JLabel label12 = new JLabel("You must exit game to guess.");
label12.setBounds(639, 1300, 800, 40);
//creating text area and setting properties
JTextArea texta1 = new JTextArea();
texta1.setOpaque(false);
texta1.setLineWrap(true);
texta1.setWrapStyleWord(true);
texta1.setBounds(100, 100, 1000, 600);
texta1.setText(Instructions);
//adding items to frames
frame1.add(button1);
frame1.add(button3);
frame2.add(button2);
frame2.add(labelhang);
frame3.add(label6);
frame2.add(label4);
frame2.add(label5);
frame3.add(label6);
frame1.add(label7);
frame1.add(texta1);
frame1.add(button4);
frame2.add(label8);
frame2.add(label9);
frame2.add(label10);
frame2.add(label11);
frame2.add(label12);
//set item properties
labelresult.setVisible(false);
button2.setVisible(false);
labelhang.setIcon(hanginit);
label4.setVisible(false);
label5.setVisible(false);
label7.setVisible(false);
texta1.setVisible(false);
button4.setVisible(false);
label8.setVisible(false);
label9.setVisible(false);
label10.setBorder(border);
label11.setVisible(false);
label12.setVisible(false);
//set frame properties
frame1.setLayout(null);
frame1.setVisible(true);//makes the frame visible to the user
frame3.setLayout(null);
//When End Game button is pressed
button2.addActionListener(new ActionListener(){
@Override
public void actionPerformed(ActionEvent e){
//end of game conditions
label5.setVisible(false);
label4.setVisible(false);
label12.setVisible(false);
button2.setVisible(false);
frame2.setVisible(false);
wordbank = " Letter Bank:";
badguess = 0;
amountc = 0;
if(counter == wordcount){
frame3.setVisible(true);//frame after all words gone through
}
else{
labelhang.setIcon(hanginit);
frame1.setVisible(true);
}
}
});
//When Instructions button is pressed
button3.addActionListener(new ActionListener(){
@Override
public void actionPerformed(ActionEvent e){
button1.setVisible(false);
button3.setVisible(false);
label7.setVisible(true);
texta1.setVisible(true);
button4.setVisible(true);
}
});
//When Main Menu is pressed
button4.addActionListener(new ActionListener(){
@Override
public void actionPerformed(ActionEvent e){
button1.setVisible(true);
button4.setVisible(false);
button2.setVisible(true);
label7.setVisible(false);
texta1.setVisible(false);
button3.setVisible(true);
}
});
//When New Game is press
button1.addActionListener(new ActionListener(){
@Override
public void actionPerformed(ActionEvent e){
//set item properties
frame2.setLayout(null);
frame2.setVisible(true);
frame1.setVisible(false);
button2.setVisible(false);
label8.setVisible(false);
label9.setVisible(false);
wordbank = " Letter Bank:";
label10.setText(wordbank);
//initializes labels and word
for(int i=0; i<20; i++){
labels[i].setText(" ");
}
String currentword = randwords[counter];
counter++;
//initializing previos guesses
for(int i=0; i<26; i++){
guesses[i] = ' ';
}
nguesses = 0;
//creating panel and panel components always create panels and all components in the same place that they are being added
JButton send = new JButton("Send");
JButton clear = new JButton("clear");
JTextField tf = new JTextField(1);
JLabel label = new JLabel("Enter Guess");
JPanel panel = new JPanel();
panel.add(label);
panel.add(tf);
panel.add(send);
panel.add(clear);
panel.setBounds(xcent2 - 250, ylim2 - 102, 500, 40);
frame2.add(panel);
//placing labels for letters
int letters = currentword.length();
int spacing2 = 800-(int)(letters*12.5);
for (int i=0; i<letters; i++){
labels[i].setText("_");
int spacing = 25 * i;
labels[i].setBounds(spacing2 + spacing, 1100, 25, 40);
frame2.add(labels[i]);
}
//when clear button is pressed
clear.addActionListener(new ActionListener(){
@Override
public void actionPerformed(ActionEvent e){
tf.setText("");
}
});
//when send button is pressed
send.addActionListener(new ActionListener(){
int amountc1 = 0;//keeps track of correctly guessed amount of words
int counter2 = 0;//keeps track of amount of correct letter guesses for each word
int letters2 = 0;
@Override
public void actionPerformed(ActionEvent e){
//initialize word and user guess
String currentword = randwords[counter-1];
letters2 = currentword.length();
char[] wordcurrent = new char[20];
wordcurrent = currentword.toCharArray();
String userguess = tf.getText();
userguess = userguess.toLowerCase();
tf.setText("");
//set properties
label4.setVisible(false);
label5.setVisible(false);
label8.setVisible(false);
label9.setVisible(false);
label11.setVisible(false);
//checking guess with word
boolean flag2 = false;
boolean flag3 = false;
//checking if word is already solved and user is entering data
System.out.println(badguess);
System.out.println(amountc);
System.out.println(nguesses);
if(nguesses > badguess + amountc){
label4.setVisible(false);
label5.setVisible(false);
label12.setVisible(true);
nguesses++;
flag2 = true;
}
else if(userguess.length() > 1){
label8.setVisible(true);
flag2 = true;
nguesses++;
}
else if(userguess.length() < 1){
label9.setVisible(true);
flag2 = true;
nguesses++;
}
else{
char[] guessuser = userguess.toCharArray();
char guessedchar = guessuser[0];
int charval = (int)guessedchar;//97-122 lowercase, 65-90 for uppercase
//checks for previous guesses
for(int t=0; t<=nguesses; t++){
if(guessedchar == guesses[t]){
flag3 = true;
break;
}
}
nguesses++;
//checking word against guess
for(int i=0; i<letters2; i++){
if(!flag3){
if(((charval>96 & charval<123))){
guesses[nguesses] = guessedchar;
if(wordcurrent[i] == guessedchar){
labels[i].setText(userguess);
labels[i].setVisible(true);
flag2 = true;
counter2++;
nguesses++;
amountc++;
}
}
else{
label9.setVisible(true);
flag2 = true;
}
}
else{
label11.setVisible(true);
flag2 = true;
}
}
}
//checks if full word is guessed correctly
if(counter2 == letters2){
this.amountc1++;
nguesses++;
button2.setVisible(true);
String correctword = "Well done! You have solved " + amountc1 + " out of " + counter;
label5.setText(correctword);
label5.setVisible(true);
counter2 = 0;
if(counter == wordcount){
label3.setText(correctword);
}
}
//checks for wrong guess and changes hangman picture accordingly
if (flag2 == false){
badguess++;
switch(badguess){
case 1:
wordbank += " " + userguess;
label10.setText(wordbank);
labelhang.setIcon(hang1);
break;
case 2:
wordbank += ", " + userguess;
label10.setText(wordbank);
labelhang.setIcon(hang2);
break;
case 3:
wordbank += ", " + userguess;
label10.setText(wordbank);
labelhang.setIcon(hang3);
break;
case 4:
wordbank += ", " + userguess;
label10.setText(wordbank);
labelhang.setIcon(hang4);
break;
case 5:
wordbank += ", " + userguess;
label10.setText(wordbank);
labelhang.setIcon(hang5);
break;
case 6:
nguesses++;
wordbank += ", " + userguess;
label10.setText(wordbank);
labelhang.setIcon(hang6);
button2.setVisible(true);
String incorrectword = "Sorry, The correct word was " + currentword + " You have solved " + amountc1 + " out of " + counter;
label4.setText(incorrectword);
label4.setVisible(true);
this.counter2 = 0;
if(counter == wordcount){
label3.setText(incorrectword);
}
break;
default:
break;
}
}
else{
nguesses--;
}
}
});
}
});
}
}
要在setText("");方法之后聚焦文本字段，您可以使用以下方法，
textFieldName.requestFocus();
要使文本字段居中，您可以使用此代码，
textFieldName.setHorizontalAlignment(JTextField.CENTER);