所有课程都是连续发布的。这个程序是正确的，直到通过创建自定义视图设置“GameActivity”的背景。但是之后当我想在Android设备中添加单个机器人时，它会显示“意外错误”。
WelcomeActivity
package com.emdad.androidapp;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnTouchListener;
import android.view.Window;
import android.view.WindowManager;
import android.widget.Button;
public class WelcomeActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);
setContentView(R.layout.activity_welcome);
final Button startButton=(Button) findViewById(R.id.androidButton);
startButton.setOnTouchListener(new OnTouchListener() {
@Override
public boolean onTouch(View arg0, MotionEvent arg1) {
switch (arg1.getAction()) {
case MotionEvent.ACTION_DOWN:
startButton.getBackground().setAlpha(100);
break;
case MotionEvent.ACTION_UP:
Intent intent=new Intent(WelcomeActivity.this, GameActivity.class);
startActivity(intent);
startButton.getBackground().setAlpha(255);
break;
case MotionEvent.ACTION_MOVE:
break;
default:
break;
}
return false;
}
});
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.welcome, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
}
GameActivity
package com.emdad.androidapp;
import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.Window;
import android.view.WindowManager;
public class GameActivity extends Activity {
GameView gameView;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);
gameView=new GameView(this);
setContentView(gameView);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.game, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
}
GameView
package com.emdad.androidapp;
import java.util.Random;
import android.content.Context;
import android.graphics.Point;
import android.view.MotionEvent;
import android.view.SurfaceHolder;
import android.view.SurfaceHolder.Callback;
import android.view.SurfaceView;
public class GameView extends SurfaceView implements Callback{
Context context;
SurfaceHolder surfaceHolder;
DrawingThread drawingThread;
public GameView(Context context) {
super(context);
this.context=context;
surfaceHolder=getHolder();
surfaceHolder.addCallback(this);
drawingThread=new DrawingThread(this, context);
}
@Override
public void surfaceChanged(SurfaceHolder arg0, int arg1, int arg2, int arg3) {
}
@Override
public void surfaceCreated(SurfaceHolder arg0) {
try {
drawingThread.start();
} catch (Exception e) {
restartThread();
}
}
private void restartThread() {
drawingThread.stopThread();
drawingThread=null;
drawingThread=new DrawingThread(this, context);
drawingThread.start();
}
@Override
public void surfaceDestroyed(SurfaceHolder arg0) {
drawingThread.stopThread();
}
@Override
public boolean onTouchEvent(MotionEvent event) {
Point touchPoint=new Point();
touchPoint=new Point((int)event.getX(), (int)event.getY());
Random random=new Random();
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
drawingThread.allRobots.add(new Robot(drawingThread.allPossibleRobots.get(random.nextInt(6)), touchPoint));
break;
case MotionEvent.ACTION_UP:
break;
case MotionEvent.ACTION_MOVE:
drawingThread.allRobots.get(drawingThread.allRobots.size()-1).setCenter(touchPoint);
break;
default:
break;
}
return super.onTouchEvent(event);
}
}
DrawingThread
package com.emdad.androidapp;
import java.util.ArrayList;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Point;
import android.view.Display;
import android.view.WindowManager;
public class DrawingThread extends Thread{
private Canvas canvas;
private GameView gameView;
private Context context;
boolean threadFlag=false;
Bitmap backgroundBitmap;
int displayX, displayY;
ArrayList<Robot> allRobots;
ArrayList<Bitmap> allPossibleRobots;
public DrawingThread(GameView gameView, Context context) {
super();
this.gameView = gameView;
this.context = context;
initializaeAll();
}
private void initializaeAll() {
WindowManager windowManager=(WindowManager) context.getSystemService(Context.WINDOW_SERVICE);
Display defaultDisplay=windowManager.getDefaultDisplay();
Point displayDimension=new Point();
defaultDisplay.getSize(displayDimension);
displayX=displayDimension.x;
displayY=displayDimension.y;
backgroundBitmap=BitmapFactory.decodeResource(context.getResources(), R.drawable.background1);
backgroundBitmap=Bitmap.createScaledBitmap(backgroundBitmap, displayX, displayY, true);
initializeAllPossibleRobots();
}
private void initializeAllPossibleRobots() {
allRobots=new ArrayList<Robot>();
allPossibleRobots=new ArrayList<Bitmap>();
allPossibleRobots.add(giveResizedRobotBitmap(R.drawable.android));
allPossibleRobots.add(giveResizedRobotBitmap(R.drawable.android2));
allPossibleRobots.add(giveResizedRobotBitmap(R.drawable.android3));
allPossibleRobots.add(giveResizedRobotBitmap(R.drawable.android6));
allPossibleRobots.add(giveResizedRobotBitmap(R.drawable.apple));
allPossibleRobots.add(giveResizedRobotBitmap(R.drawable.apple2));
}
private Bitmap giveResizedRobotBitmap(int resourceID) {
Bitmap tempBitmap=BitmapFactory.decodeResource(context.getResources(), resourceID);
tempBitmap=Bitmap.createScaledBitmap(tempBitmap, displayX/5, (tempBitmap.getHeight()/tempBitmap.getWidth())*(displayX/5), true);
return tempBitmap;
}
@Override
public void run() {
threadFlag=true;
while (threadFlag) {
canvas=gameView.surfaceHolder.lockCanvas();
try {
synchronized (canvas) {
updateDisplay();
}
} catch (Exception e) {
e.printStackTrace();
} finally{
if (canvas!=null) {
gameView.surfaceHolder.unlockCanvasAndPost(canvas);
}
}
try {
Thread.sleep(17);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
private void updateDisplay() {
canvas.drawBitmap(backgroundBitmap, 0, 0, null);
for (int i = 0; i < allRobots.size(); i++) {
Robot temprRobot=allRobots.get(i);
canvas.drawBitmap(temprRobot.robotBitmap, temprRobot.centerX-(temprRobot.width/2), temprRobot.centerY-(temprRobot.height/2), temprRobot.robotPaint);
}
}
public void stopThread() {
threadFlag=false;
}
}
机器人
package com.emdad.androidapp;
import android.graphics.Bitmap;
import android.graphics.Paint;
import android.graphics.Point;
public class Robot {
int centerX, centerY;
int height, width;
Bitmap robotBitmap;
Paint robotPaint;
public Robot(Bitmap bitmap) {
robotBitmap=bitmap;
centerX=centerY=0;
height=robotBitmap.getHeight();
width=robotBitmap.getWidth();
robotPaint=new Paint();
}
public Robot(Bitmap bitmap, int cX, int cY) {
this(bitmap);
centerX=cX;
centerY=cY;
}
public Robot(Bitmap bitmap, Point center) {
this(bitmap, center.x, center.y);
}
public void setCenter(Point centerPoint) {
centerX=centerPoint.x;
centerY=centerPoint.y;
}
}