java - 从 SurfaceView 创建类时出错，该类将作为线程运行

Question

我了解 OOP 的基本概念，我正在尝试 Android 编程。(特别是游戏)。我正在尝试通过示例实现本书《Android 游戏编程》中的游戏项目。我能够从理论上理解所说的内容。但是，当我将这些代码 fragment 组合到一个 java 类 TDView.java 文件中时，我在 Android studio 中收到错误。也许我误解了一些短语并把一 block 放在了我不应该放的地方。

以下代码中的错误标记为 error1 和 error2:

package com.gamecodeschool.c1tappydefender;
import android.content.Context;
import android.view.SurfaceView;

public class TDView extends SurfaceView implements Runnable {
    volatile boolean playing;
    Thread gameThread = null;

    @Override
    public void run() {
        while (playing) {
            update();
            draw();
            control();
        } //error2: it says a semicolon is needed here.

        private void update(){
        }
        private void draw(){
        }
        private void control(){
        }
    }// error1: it says class or interface missing

    public TDView(Context context) {
        super(context);

    }

    // Clean up our thread if the game is interrupted or the player quits
    public void pause() {
        playing = false;
        try {
            gameThread.join();
        } catch (InterruptedException e) { 

        }
    }

    // Make a new thread and start it
    // Execution moves to our R
    public void resume() {
        playing = true;
        gameThread = new Thread(this);
        gameThread.start();
    }
}

Answer 1

将方法声明移到运行方法的声明之外。这应该可以解决问题

public void run() {
  while (playing) {
    update();
    draw();
    control();
  }
}

private void update(){
}

private void draw(){
}

private void control(){
}