我正在尝试在Android Studio中使用一个MainActivity.java类来控制RC汽车，我仍然在工作，因为这是一个早期的原型代码。
我目前正在努力解决为什么我的surfaceHolder.getSurface（）。isValid（）每次都返回false。除了实现一个Callback类之外我找不到任何帮助，但是，之前我已经能够使用完全相同的代码行来模仿我的surfaceHolder并且从不需要一个Callback类，唯一的例外是类扩展的SurfaceView，这个不是因为我只能扩展一个班级。以下是我的代码：
package com.example.hughman.cccontrol;
import android.graphics.Point;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.Display;
import android.view.MotionEvent;
import android.view.View;
import android.view.Window;
import android.view.WindowManager;
import android.view.SurfaceView;
import android.view.SurfaceHolder;
import android.widget.ImageButton;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Paint;
public class MainActivity extends AppCompatActivity implements View.OnClickListener, Runnable{
private ImageButton breakButton, connectButton;
private Bitmap left_thumb, left_thumb_resized, right_thumb_resized;
private Context context;
private int screenW, screenH, thumb_x, thumb_y, drag_x, drag_y, current_thumb = -1;
private Canvas canvas;
private Paint paint = new Paint();
private SurfaceHolder surfaceHolder;
private Thread thread;
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
SurfaceView surfaceView = new SurfaceView(this);
paint.setAntiAlias(true);
//puts the app in full screen mode
requestWindowFeature(Window.FEATURE_NO_TITLE);
this.getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);
setContentView(R.layout.activity_main);
surfaceHolder = surfaceView.getHolder();
//initalize screen size
Display display = getWindowManager().getDefaultDisplay();
Point size = new Point();
display.getSize(size);
screenH = size.x;
screenW = size.x;
//initialize buttons
breakButton = findViewById(R.id.breakbutton);
connectButton = findViewById(R.id.connectbutton);
breakButton.setOnClickListener(this);
connectButton.setOnClickListener(this);
left_thumb = BitmapFactory.decodeResource(this.getResources(), R.drawable.thumbstick);
left_thumb_resized = Bitmap.createScaledBitmap(left_thumb, 500, 500, false);
right_thumb_resized = Bitmap.createScaledBitmap(left_thumb, 500, 500, false);
thread = new Thread(this);
thread.start();
}
@Override
public void run() {
if(current_thumb == -1) {
drawInitialBitmap();
}
else
{
reDraw(drag_x, drag_y);
}
System.out.println("Run Test");
setFPS();
}
public void drawInitialBitmap()
{
thumb_x = 800;
thumb_y = (screenH / 2) + 250;
if (surfaceHolder.getSurface().isValid()) {
System.out.println("Hello");
canvas = surfaceHolder.lockCanvas();
canvas.drawBitmap(left_thumb_resized, thumb_x, thumb_y, paint);
canvas.drawBitmap(right_thumb_resized, thumb_x * 2, thumb_y, paint);
surfaceHolder.unlockCanvasAndPost(canvas);
}
}
public void reDraw(int x, int y)
{
if (surfaceHolder.getSurface().isValid()) {
canvas = surfaceHolder.lockCanvas();
if (current_thumb == 1) {
canvas.drawBitmap(left_thumb_resized, x, y, paint);
} else if (current_thumb == 2) {
canvas.drawBitmap(right_thumb_resized, x, y, paint);
}
surfaceHolder.unlockCanvasAndPost(canvas);
}
}
//method for when user selects an xml button
public void onClick(View v) {
if (v == connectButton) {
//prompts to connect to Bluetooth
System.out.println("ConectButton");
}
else if(v == breakButton)
{
System.out.println("BreakButton");
//halt all motors
}
}
public boolean onTouchEvent(MotionEvent event){
int action = event.getAction();
int drag_x = (int) event.getX(); // or getRawX();
int drag_y = (int) event.getY();
switch(action){
case MotionEvent.ACTION_DOWN:
if (drag_x >= thumb_x && drag_x < (thumb_x + left_thumb_resized.getWidth())
&& drag_y >= thumb_y && drag_y < (thumb_y + left_thumb_resized.getHeight())) {
current_thumb = 1;
return true;
}
else if (drag_x >= thumb_x * 2 && drag_x < ((thumb_x * 2) + right_thumb_resized.getWidth())
&& drag_y >= thumb_y && drag_y < (thumb_y + right_thumb_resized.getHeight())) {
current_thumb = 2;
return true;
}
break;
case MotionEvent.ACTION_MOVE:
if(current_thumb != -1)
{
System.out.println(Math.sqrt(Math.pow(drag_x - thumb_x, 2) + Math.pow(drag_y - thumb_y, 2)));
System.out.println(Math.sqrt(Math.pow(drag_x - (thumb_x * 2), 2) + Math.pow(drag_y - thumb_y, 2)));
//move left thumb
return true;
}
break;
case MotionEvent.ACTION_UP:
current_thumb = -1;
drawInitialBitmap();
break;
default:
}
return false;
}
public void setFPS() {
try {
thread.sleep(17);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
一切都运行良好并且构建正确，但是没有拇指棒正在被绘制。我没有限制拇指棒的运动，但后来我会补充一下。至于现在，我希望能够沿着我想要移动的方向拖动它们，使用距离函数来简单地计算出我想要拖动它们的距离。
是否可以在不扩展SufaceView的情况下执行此操作？或者制作一个Callback类？为什么？下面我将添加我以前没有使用Callback类的项目中的代码，请记住代码很麻烦，因为我们有多个人正在处理该项目，并且所需的截止日期为24小时。
package com.example.michael.doyouknowdeway;
import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.widget.ImageButton;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Rect;
import android.media.MediaPlayer;
import android.view.MotionEvent;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.TimeUnit;
/**
* Created by michael on 1/27/18.
* The big class that does most of the work for the code, sets the overall view of the game, getting
* the character, tiles, and player motions all together for a working game. Took us the most time
* to work on with many bugs occuring along de wae.
*/
public class GameView extends SurfaceView implements Runnable{
//
volatile boolean isPlaying = true, init = true, isPassOver = true;
private Thread gameThread = null;
private SurfaceHolder surfaceHolder;
private Canvas canvas;
private Context context;
private Activity activity;
private int screenWidth = 0, screenHeight = 0, move_const = 1;
private Player player;
private MediaPlayer jumpNoise, eatNoise;
private Bitmap backgroundImage;
private MediaPlayer backgroundMusic;
private MediaPlayer endGameSound;
private Bitmap backgroundImageResized;
Tile currentTile, nextTile;
private ScheduledExecutorService executorService;
private Paint paint = new Paint();
private Paint textPaint = new Paint();
private FireBall fireball;
private int scoreCount = 0, passOver;
private Bitmap endImage;
private Bitmap endImageResized;
private Bitmap run1, podCount;
private Bitmap run1Resized, podCountResized;
private Bitmap run2;
private Bitmap playerJumpImage;
private boolean isRun1 = false;
private ImageButton redoButton;
//starts of the program, creating the background for the game based on the dimensions of the
//phone being used
public GameView(Context context, int screenX, int screenY) {
super(context);
//load images into game
backgroundImage = BitmapFactory.decodeResource(context.getResources(), R.drawable.background_sky);
backgroundImageResized = Bitmap.createScaledBitmap(backgroundImage, screenX, screenY, false);
podCount = BitmapFactory.decodeResource(context.getResources(), R.drawable.detergent_pod);
run1 = BitmapFactory.decodeResource(context.getResources(), R.drawable.knuckles_run);
run1Resized = Bitmap.createScaledBitmap(run1, 200, 200, false);
podCountResized = Bitmap.createScaledBitmap(podCount, 100, 100, false);
run2 = BitmapFactory.decodeResource(context.getResources(), R.drawable.ugandan_knuckle);
playerJumpImage = BitmapFactory.decodeResource(context.getResources(), R.drawable.knucklesjump);
//load sounds into game
jumpNoise = MediaPlayer.create(context, R.raw.jump_takeoff);
eatNoise = MediaPlayer.create(context, R.raw.eat_1);
backgroundMusic = MediaPlayer.create(context, R.raw.music_baby);
endGameSound = MediaPlayer.create(context, R.raw.end_game);
//initialize other important stuff
textPaint.setColor(Color.WHITE);
textPaint.setTextSize(72);
textPaint.setStyle(Paint.Style.FILL);
paint.setAntiAlias(true);
screenWidth = screenX;
screenHeight = screenY;
activity = (Activity) context;
backgroundMusic.start();
this.context = context;
player = new Player(context, screenX, screenY);
fireball = new FireBall(context, screenX, screenY);
currentTile = new Tile(context, 3, screenWidth + 400, screenHeight);
currentTile.fillTile();
surfaceHolder = getHolder();
//controls "running" animation
executorService = Executors.newSingleThreadScheduledExecutor();
executorService.scheduleAtFixedRate(new Runnable() {
@Override
public void run() {
if(!player.isJumping) {
if (!isRun1) {
run1Resized = Bitmap.createScaledBitmap(run1, 200, 200, false);
isRun1 = true;
} else {
run1Resized = Bitmap.createScaledBitmap(run2, 200, 200, false);
isRun1 = false;
}
}
}
}, 0, 200, TimeUnit.MILLISECONDS); //can change "speed" of run by altering the second param
}
/**
* Main game loop
*/
public void run() {
while (isPlaying) {
update();
draw();
setFPS();
}
}
/**
* Redraws the screen in the new positions, creating continuous movement for the game
*/
public void draw() {
if (surfaceHolder.getSurface().isValid()) {
canvas = surfaceHolder.lockCanvas();
canvas.drawColor(Color.WHITE);
canvas.drawBitmap(backgroundImageResized, 0, 0, paint);
canvas.drawBitmap(podCountResized, 0, 0, paint);
String scoreCountStr = Integer.toString(scoreCount);
if(0 >= (currentTile.getLength() * 100) - move_const)
{
currentTile = new Tile(nextTile);
isPassOver = true;
nextTile = null;
move_const = 0;
}
if(init) {
init = false;
for (int i = 0; i < currentTile.getLength(); i++) {
for (int j = currentTile.getHeight() - 1; j >= 0; j--) {
if (currentTile.getBlock(i, j) != null) {
canvas.drawBitmap(currentTile.getBlock(i, j).getImage(), (i * 100), (j * 100) + 10, paint);
}
}
}
}
else
{
for (int i = 0; i < currentTile.getLength(); i++) {
for (int j = currentTile.getHeight() - 1; j >= 0; j--) {
if (currentTile.getBlock(i, j) != null) {
canvas.drawBitmap(currentTile.getBlock(i, j).getImage(), (i * 100) - move_const, (j * 100) + 10, paint);
}
if (nextTile != null) {
if (i < nextTile.getLength() && j < nextTile.getHeight()) {
if (nextTile.getBlock(i, j) != null) {
canvas.drawBitmap(nextTile.getBlock(i, j).getImage(), ((i + currentTile.getLength()) * 100) - move_const, (j * 100) + 10, paint);
}
}
}
}
}
move_const += 10;
}
if(fireball.isShooting) {
canvas.drawBitmap(fireball.getImage(), fireball.getXVal(), fireball.getYVal(), paint);
}
canvas.drawBitmap(run1Resized,player.getXVal(), player.getYVal(), paint);
canvas.drawText(scoreCountStr, 120, 80, textPaint);
//releases the canvas to be redrawn again
surfaceHolder.unlockCanvasAndPost(canvas);
}
}
/**
* updates the positions of everything on the screen if needed
*/
public void update() {
player.update();
if(fireball.isShooting) {
fireball.update(player);
}
if((((currentTile.getLength() - (screenWidth/100) )* 100) - move_const <= 200) && nextTile == null){
nextTile = currentTile.getNextTile();
}
if(player.getYVal() >= screenHeight || player.getXVal() <= 0){
gameOver();
}
detectCollisions();
}
//initially sets player to not be colliding - changed almost instantly
static boolean isColliding = false;
//
/**
* Detects collisions so the player can collect tide pods and jump off of surfaces.
*/
public void detectCollisions(){
int highestY = 9;
int currentX = (250 + move_const)/100;
if(currentX >= currentTile.getLength() && isPassOver)
{
passOver = -10;
isPassOver = false;
}
else
{
passOver= -25; //arbitrary
}
for(int i = 0; i < currentTile.getHeight(); i++)
{
if(currentX >= currentTile.getLength())
{
passOver += 10;
if(nextTile.getBlock(passOver/100, i) != null)
{
if(!nextTile.getBlock(passOver/100, i).isPod())
{
highestY = i;
break;
}
}
}
else if(currentTile.getBlock(currentX, i) != null)
{
if(!currentTile.getBlock(currentX, i).isPod())
{
highestY = i;
break;
}
}
else
{
highestY = -1;
}
}
checkGroundCollision(highestY);
checkTidePodCollision(currentTile, nextTile);
checkForwardCollision(nextTile, currentX, highestY, passOver);
}
/**
* Method used to check if the player has hit a wall in front of them.
* @param next - the next tile
* @param x - player x position
* @param y - player y position
* @param passOver - the location being passed over.
*/
public void checkForwardCollision(Tile next, int x, int y, int passOver)
{
boolean collision = false;
Rect rect = new Rect();
if(next != null && passOver >= 0)
{
rect.top = y * 100;
rect.bottom = screenHeight;
rect.left = passOver + (player.getBitmap().getWidth() / 2);
rect.right = passOver + (player.getBitmap().getWidth() / 2) + 100;
collision = Rect.intersects(player.getHitBox(), rect);
}
else
{
rect.top = y * 100;
rect.bottom = screenHeight;
rect.left = (x+1)* 100;
rect.right = (x+2) * 100;
collision = Rect.intersects(player.getHitBox(), rect);
}
//if collision is true, half player movement until its not true
}
/**
* Method that checks if a player has hit a tidepod, if so, adds to score count
* @param current - the current tile
* @param next - the next tile
*/
public void checkTidePodCollision(Tile current, Tile next)
{
if(next != null && !isPassOver)
{
for(double iter: next.getTidePods())
{
int x = (int) iter;
int y = (int) (iter - x)*10;
boolean hit = podCollision(x, y);
if(hit)
{
eatNoise.start();
scoreCount += 10;
System.out.println("Cur Next: " + x + " || " + y);
nextTile.setNullBlock(x, y);
return;
}
}
}
else
{
for(double iter: current.getTidePods())
{
int x = (int) iter;
double temp = x;
int y = (int) ((iter - temp)*10.00);
boolean hit = podCollision(x, y);
if(hit)
{
eatNoise.start();
scoreCount += 10;
System.out.println("Current: " + x + " || " + y);
currentTile.setNullBlock(x, y);
return;
}
}
}
}
//compliment to the previous method
private boolean podCollision(int x, int y) {
Rect tideRect = new Rect();
if(isPassOver && x < 3)
{
System.out.println("TEST: " + x + " || " + y);
tideRect.top = (y * 100);
tideRect.left = x * 100 + passOver + 10;
tideRect.right = (x + 2) * 100 + passOver;
tideRect.bottom = (y + 2) * 100 + 10;
}
else {
tideRect.top = y * 100;
tideRect.left = x * 100 - move_const + 10;
tideRect.right = (x + 2) * 100 - move_const;
tideRect.bottom = (y + 2) * 100 + 10;
}
return Rect.intersects(player.getHitBox(), tideRect);
}
/**
* Method used for jumping off of the ground.
* @param highestY
*/
private void checkGroundCollision(int highestY) {
Rect blockRect = new Rect();
boolean GroundCollision;
if(highestY >= 0) {
blockRect.top = (highestY) * 100 - 25;
blockRect.left = 200;
blockRect.right = 300;
//changed this valued -- this is to remind myself
blockRect.bottom = highestY * 100 + 25; //still needs work //make player hitbox just his feet
GroundCollision = Rect.intersects(player.getFeetBox(), blockRect);
System.out.println("WWWWWW : " + GroundCollision);
}
else
{
GroundCollision = false;
}
if(GroundCollision){
isColliding = true;
} else {
player.isFalling = true;
isColliding = false;
}
}
/**
* Sets the FPS to roughly 60 fps
*/
public void setFPS() {
try {
gameThread.sleep(17);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
/**
* Method that
*/
public void gameOver() {
//end image is not currently working
endImage = BitmapFactory.decodeResource(context.getResources(), R.drawable.end_game);
endImageResized = Bitmap.createScaledBitmap(endImage, 100, 200, false);
canvas.drawBitmap(endImageResized, screenWidth/2, screenHeight/2, paint);
//free up memory from bitmaps
backgroundImage.recycle();
backgroundImage = null;
backgroundImageResized.recycle();
backgroundImageResized = null;
podCount.recycle();
podCount = null;
podCountResized.recycle();
podCountResized = null;
backgroundImage.recycle();
backgroundImage = null;
run1.recycle();
run1 = null;
run1Resized.recycle();
run1Resized = null;
run2.recycle();
run2 = null;
playerJumpImage.recycle();
playerJumpImage = null;
backgroundMusic.stop();
Runtime.getRuntime().gc(); //manually run garbage collector
endGameSound.start();
context.startActivity(new Intent(context,MainActivity.class));
}
/**
* Method used to dictate what to do when the android screen is touched.
* @param event - the type of touch on the screen
* @return - true when screen is touched
*/
public boolean onTouchEvent(MotionEvent event){
int touchAction = event.getAction();
if(touchAction == MotionEvent.ACTION_DOWN){
if(event.getX() < (screenWidth / 2)) {
jumpNoise.start();
if(!player.isJumping && !player.isFalling) {
player.setYval(player.getYVal());
player.isJumping = true;
run1Resized = Bitmap.createScaledBitmap(playerJumpImage, 200, 200, false);
}
else if(player.getJumpCount() < 1)
{
player.setYval(player.getYVal());
player.incrJump();
player.isJumping = true;
run1Resized = Bitmap.createScaledBitmap(playerJumpImage, 200, 200, false);
}
} else {
fireball.setOnScreen(true);
}
}
return true;
}
/**
* Method that pauses the game when necessary (i.e when home button is pressed)
*/
public void pause() {
isPlaying = false;
backgroundMusic.pause();
try {
gameThread.join();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
/**
* Resumes the game after a pause
*/
public void resume() {
isPlaying = true;
backgroundMusic.start();
gameThread = new Thread(this);
gameThread.start();
}
}
感谢您的时间和任何帮助表示赞赏！
编辑：也使用位图重绘等，因为这是我习惯的。