java - java-libGDX 中的文本屏幕实现

Question

我在实现显示和使用玩家用户名的功能时遇到了一些麻烦。我正在制作 Windows 和安卓之间的跨平台应用程序，我试图在他们开始输入时立即显示玩家的名字，并且可以按回车键继续或按关卡选择-按钮进入下一个屏幕。每次我按 ''Enter'' 时，它都会崩溃。此外，它不显示或接受玩家的名字。我知道代码不是最佳的，因为我制作了多个表格，但我希望有人能告诉我我在哪里犯了错误，这样它可能会起作用。提前致谢!

这是代码:

package com.paladinzzz.game.screens;

import com.badlogic.gdx.Gdx;
import com.badlogic.gdx.Input;
import com.badlogic.gdx.Screen;
import com.badlogic.gdx.graphics.GL20;
import com.badlogic.gdx.graphics.OrthographicCamera;
import com.badlogic.gdx.graphics.Texture;
import com.badlogic.gdx.graphics.g2d.BitmapFont;
import com.badlogic.gdx.graphics.g2d.TextureRegion;
import com.badlogic.gdx.scenes.scene2d.InputEvent;
import com.badlogic.gdx.scenes.scene2d.Stage;
import com.badlogic.gdx.scenes.scene2d.ui.ImageButton;
import com.badlogic.gdx.scenes.scene2d.ui.Table;
import com.badlogic.gdx.scenes.scene2d.ui.TextButton;
import com.badlogic.gdx.scenes.scene2d.utils.ClickListener;
import com.badlogic.gdx.scenes.scene2d.utils.Drawable;
import com.badlogic.gdx.scenes.scene2d.utils.TextureRegionDrawable;
import com.badlogic.gdx.utils.viewport.FillViewport;
import com.paladinzzz.game.CrossplatformApp;
import com.paladinzzz.game.util.Constants;
import com.paladinzzz.game.audio.MusicHandler;
import static com.badlogic.gdx.Gdx.input;
import static com.paladinzzz.game.screens.MenuScreen.musicHandler;


public class LoginScreen implements Screen {

private CrossplatformApp game;
private Stage stage;
private ImageButton backButton, playButton;
private Texture backTexture, playTexture, background;
private Drawable drawableBack, drawablePlay;
private OrthographicCamera camera;
BitmapFont font = new BitmapFont();
int[] x = new int[255];
public static boolean inPlayscreen = false;
public static String playername = "";
private boolean isConverted = false;
private Table table, table2;

public LoginScreen(CrossplatformApp game) {
    this.game = game;
    this.camera = new OrthographicCamera();
    this.stage = new Stage(new FillViewport(Constants.WIDTH, Constants.HEIGHT, camera));
    this.playTexture = new Texture("Screens/LoginScreen/LvlSelection.png");
    this.backTexture = new Texture("Screens/BackButton.png");
    this.background = new Texture("Screens/LoginScreen/loginscreen.png");
}

@Override
public void show() {

    //Give the texture of the backButton to a new ImageButton
    drawableBack = new TextureRegionDrawable(new TextureRegion(backTexture));
    backButton = new ImageButton(drawableBack);
    backButton.addListener(new ClickListener(){
        @Override
        public void clicked(InputEvent event, float x, float y) {
            game.setScreen(new MenuScreen(game));
            MenuScreen.musicHandler.stopMusic();
        }
    });

    //Give the texture of the playButton to a new ImageButton
    drawablePlay = new TextureRegionDrawable(new TextureRegion(playTexture));
    playButton = new ImageButton(drawablePlay);
    playButton.addListener(new ClickListener(){
        @Override
        public void clicked(InputEvent event, float x, float y) {
            game.setScreen(new LevelScreen(game));
            inPlayscreen = true;
        }
    });


    //Elements can be added here to the stage
    input.setInputProcessor(stage);

    //A table gets made with the button which leads to the level selection screen
    table = new Table();
    table.bottom();
    table.setFillParent(true);
    table.add(playButton).padBottom(40);
    stage.addActor(table);

    //A table gets made with the button which leads back to the main menu
    table2 = new Table();
    table2.bottom();
    table2.setFillParent(true);
    table2.add(backButton).padBottom(13).padRight(640);
    table2.row();
    stage.addActor((table2));
}

@Override
public void render(float delta) {

    Gdx.gl.glClearColor(1, 0, 0, 1);
    Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);

    if(Gdx.input.isKeyJustPressed(Input.Keys.ENTER)){
        game.setScreen(new LevelScreen(game));
        inPlayscreen = true;


        if (!isConverted){
            playername = playername.substring(0, 1).toUpperCase() + playername.substring(1, playername.length()).toLowerCase();
            isConverted = true;
        }
    }

    game.batch.begin();

    //A possibility gets made to insert the name of the player
    game.batch.draw(background, 0, 0, Gdx.graphics.getWidth(), Gdx.graphics.getHeight());
    for (int i : x) {
        if (input.isKeyJustPressed(i)){
            if (i != 62 && i != 67 && i!= 66) {
                playername += Input.Keys.toString(i).toLowerCase();
            } else if (i == 67 & playername.length() > 0){
                playername = playername.substring(0, playername.length() - 1).toLowerCase();
            } else {
                playername += " ";
            }
        }
    }

    font.draw(game.batch, playername, 0, 0);

    game.batch.end();
    stage.draw();
}

@Override
public void resize(int width, int height) {

}

@Override
public void pause() {

}

@Override
public void resume() {

}

@Override
public void hide() {

}

@Override
public void dispose() {
    stage.dispose();

}
}

这是 ''LoginScreen'' 的样子: GameScreen

这是错误信息:

Exception in thread "LWJGL Application" 
java.lang.StringIndexOutOfBoundsException: String index out of range: 1
at java.lang.String.substring(String.java:1963)
at com.paladinzzz.game.screens.LoginScreen.render(LoginScreen.java:108)
at com.badlogic.gdx.Game.render(Game.java:46)
at com.paladinzzz.game.CrossplatformApp.render(CrossplatformApp.java:30)
at com.badlogic.gdx.backends.lwjgl.LwjglApplication.mainLoop(LwjglApplication.java:225)
at com.badlogic.gdx.backends.lwjgl.LwjglApplication$1.run(LwjglApplication.java:126)

断点调试:

Answer 1

崩溃解决方案针对这一行:

playername = playername.substring(0, 1).toUpperCase() + playername.substring(1, playername.length()).toLowerCase();

你的第二个子字符串需要使用

playername.length()-1