我是android新手，我正处于创建一个应用程序的完成阶段。 但不幸的是，在Android手机中运行时会出现一些错误，但在android模拟器中完美运行...
这是我的java代码：
包com.VRG;
import java.util.ArrayList;
import java.util.List;
import java.util.Random;
import java.util.Vector;
import android.app.Activity;
import android.app.AlertDialog;
import android.content.DialogInterface;
import android.content.Intent;
import android.media.MediaPlayer;
import android.media.MediaPlayer.OnCompletionListener;
import android.os.Bundle;
import android.os.CountDownTimer;
import android.util.Log;
import android.view.KeyEvent;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toast;
public class Animalsgame extends Activity implements OnClickListener {
// int answer=0;
Button voice;
MediaPlayer mp;
TextView time;// count down timer
ImageView img_view1;
ImageView img_view2;
ImageView img_view3;
ImageView img_view4;
private ImageView selectedImageView;
static int index = 0;
static int index1 = 0;
static int noOfLapse;
static int count;
static int score = 1;
static boolean isSoundPlay;
CountDownTimer CountDownTimer;
int idx;
Integer next;
private Random random;
private ArrayList<MediaPlayer> sounds;
private ArrayList<MediaPlayer> tempSounds;
// Track the sound which is playing
private int soundSelectedIndex;
private Vector matchImages = null;
List<Integer> generated;
// Total number of image boxes
private static final int NO_IMAGE_BOXES = 4;
final int[] imageViews = { R.id.img_view1, R.id.img_view2, R.id.img_view3,
R.id.img_view4 };// Array of image views
int[] Animals_images = { R.drawable.cow, R.drawable.lion, R.drawable.dog,
R.drawable.sheep, R.drawable.elephant, R.drawable.camel,
R.drawable.rhinos, R.drawable.horse, R.drawable.donkey,
R.drawable.wolf }; // Array of Animal images
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.game);
time = (TextView) this.findViewById(R.id.time);
img_view1 = (ImageView) this.findViewById(R.id.img_view1);
img_view2 = (ImageView) this.findViewById(R.id.img_view2);
img_view3 = (ImageView) this.findViewById(R.id.img_view3);
img_view4 = (ImageView) this.findViewById(R.id.img_view4);
img_view1.setOnClickListener(this);
img_view2.setOnClickListener(this);
img_view3.setOnClickListener(this);
img_view4.setOnClickListener(this);
// Count down timer
voice = (Button) this.findViewById(R.id.voice);// Animals sounds
voice.setOnClickListener(this);
// Initialise Lapse counter
noOfLapse = 0;
isSoundPlay = true;
random = new Random();
sounds = new ArrayList<MediaPlayer>();
sounds.add(MediaPlayer.create(this, R.raw.cow));
sounds.add(MediaPlayer.create(this, R.raw.lion));
sounds.add(MediaPlayer.create(this, R.raw.dog));
sounds.add(MediaPlayer.create(this, R.raw.sheep));
sounds.add(MediaPlayer.create(this, R.raw.elephant));
sounds.add(MediaPlayer.create(this, R.raw.camel));
sounds.add(MediaPlayer.create(this, R.raw.rhino));
sounds.add(MediaPlayer.create(this, R.raw.horse));
sounds.add(MediaPlayer.create(this, R.raw.donkey));
sounds.add(MediaPlayer.create(this, R.raw.wolf));
tempSounds = (ArrayList<MediaPlayer>) sounds.clone();
enableDisableImageView(false);
}// End of Oncreate method
public void setDuration(int duration) {
}
@Override
public void onClick(View v) {
Log.i("voice", "voice button clicking");
enableDisableImageView(true);
if (v instanceof ImageView) {
count++;
// Toast.makeText(getApplicationContext(), "Wrong",
// Toast.LENGTH_SHORT).show();
enableDisableImageView(false);
}
if (v == selectedImageView) {
Toast.makeText(getApplicationContext(), "Correct!",
Toast.LENGTH_SHORT).show();
score++;
Log.i("11111", "count value:" + score);
Log.i("22222", "count value:" + count);
enableDisableImageView(false);
}
if (v == img_view1) {
if (mp != null) {
if (mp.isPlaying()) {
mp.stop();
}
}
time.setText("");
if (CountDownTimer != null) {
CountDownTimer.cancel();
}
enableDisableButton(true);
}
if (v == voice) {
// answer++;
freezeButtonAndPlaySoundThenUnfreezeButton();
loadImages();
countDown();
// enableDisableButton(true);
}
if (v == img_view2) {
if (mp != null) {
if (mp.isPlaying()) {
mp.stop();
}
}
enableDisableButton(true); // Re-enable buttons
}
// else if (v == voice) {
// loadImages();
// countDown();
// enableDisableButton(false);
// }
if (v == img_view3) {
if (mp != null) {
if (mp.isPlaying()) {
mp.stop();
}
}
enableDisableButton(true); // Re-enable buttons
}
// else if (v == voice) {
// loadImages();
// countDown();
// enableDisableButton(false);
// }
if (v == img_view4) {
if (mp != null) {
if (mp.isPlaying()) {
mp.stop();
}
}
enableDisableButton(true); // Re-enable buttons
}
// else if (v == voice) {
// loadImages();
// countDown();
// enableDisableButton(false);
// }
if (count > 8) {
AlertDialog.Builder alertbox = new AlertDialog.Builder(this);
setDuration(0);
mp = MediaPlayer.create(this, R.raw.claps);
if (mp != null) {
if (mp.isPlaying()) {
mp.stop();
}
}
mp.start();
Toast.makeText(getApplicationContext(), "Your Score : " + score,
Toast.LENGTH_SHORT).show();
// set the message to display
alertbox.setMessage("Game Over..!" + " " + "Your score is:" + " "
+ score + " " + " Do you want to play again?");
// set a positive/yes button and create a listener
alertbox.setPositiveButton("Yes",
new DialogInterface.OnClickListener() {
// do something when the button is clicked
public void onClick(DialogInterface arg0, int arg1) {
if (mp != null) {
if (mp.isPlaying()) {
mp.stop();
}
}
index = 0;
index1 = 0;
count = 0;
score = 1;
Intent i = new Intent(Animalsgame.this,
Animalsgame.class);
startActivity(i);
finish();
}
});
// set a negative/no button and create a listener
alertbox.setNegativeButton("No",
new DialogInterface.OnClickListener() {
// do something when the button is clicked
public void onClick(DialogInterface arg0, int arg1) {
if (mp != null) {
if (mp.isPlaying()) {
mp.stop();
}
}
count = 0;
score = 0;
finish();
// Intent i = new Intent(VRGActivity2.this,
// VRGActivity1.class);
// startActivity(i);
}
});
// display box
alertbox.show();
enableDisableButton(false);
}
}// End of voice on click
private void countDown() {
CountDownTimer = new CountDownTimer(6000, 10000) {
public void onTick(long millisUntilFinished) {
if (isSoundPlay) {
// freezeButtonAndPlaySoundThenUnfreezeButton();
isSoundPlay = false;
}
time.setText("" + "" + millisUntilFinished / 10000);
}
public void onFinish() {
// time.setText("UP");
setDuration(0);
// Toast.makeText(getApplicationContext(), "Time Up",
// Toast.LENGTH_SHORT).show();
isSoundPlay = true;
}// End of on finish
}.start(); // End of countDown Constructor
}// End of countDown method
public void enableDisableButton(Boolean state) {
voice.setEnabled(state);
}// End of enableDisableButton(Boolean state)
public void enableDisableImageView(Boolean state) {
img_view1.setEnabled(state);
img_view2.setEnabled(state);
img_view3.setEnabled(state);
img_view4.setEnabled(state);
}// End of enableDisableImageView(Boolean state)
private void loadImages() {
Random rng = new Random(); // Random function
if (generated == null) {
generated = new ArrayList<Integer>();
} else {
generated.clear();
}
Log.i(this.toString(), "soundSelectedIndex " + soundSelectedIndex);
generated.add(soundSelectedIndex);
Log.i(this.toString(), "Initial Array Count " + generated.size());
Boolean flag;
for (int i = 0; i < NO_IMAGE_BOXES - 1; i++) {
Log.i(this.toString(), "For i " + i);
flag = true;
while (flag) {
next = rng.nextInt(9);
index = next;
if (!generated.contains(next)) {
Log.i(this.toString(), "Generated Array Contents " + next);
generated.add(next);
// ImageView iv = (ImageView) findViewById(imageViews[i]);
// iv.setImageResource(Animals_images[next]);
flag = !flag;
}// End of if
// break;
}// While loop
}// End of for loop
// Set the last image
// Choose the random position
int pos = rng.nextInt(3);
int temp = generated.get(0);
generated.set(0, generated.get(pos));
generated.set(pos, temp);
selectedImageView = (ImageView) findViewById(imageViews[pos]);
for (int i = 0; i < generated.size(); i++) {
Log.i("Array Element in the list", " " + generated.get(i));
ImageView iv = (ImageView) findViewById(imageViews[i]);
iv.setImageResource(Animals_images[generated.get(i)]);
}
}// End of loadImages()
public void freezeButtonAndPlaySoundThenUnfreezeButton() {
enableDisableButton(false); // disable buttons
int randomInt = random.nextInt(tempSounds.size());
// Set the selected sounds
Log.i(this.toString(), "Random Generated Sounds " + randomInt);
// soundSelectedIndex = randomInt;
mp = tempSounds.get(randomInt);
// if (sounds.contains(tempSounds.get(randomInt))){
// Get the actual index from the sounds list
soundSelectedIndex = sounds.indexOf(tempSounds.get(randomInt));
Log.i(this.toString(), "freezeButtonAndPlaySoundThenUnfreezeButton "
+ soundSelectedIndex);
// }
tempSounds.remove(randomInt);
mp.seekTo(0);
mp.start();
mp.setOnCompletionListener(new OnCompletionListener() {
@Override
public void onCompletion(MediaPlayer mpalmost) {
}// End of on completion method
});// End of set on click listener method
}// End of freezeButtonAndPlaySoundThenUnfreezeButton method
@Override
// while back pressed the task is refreshed
public void onBackPressed() {
if (mp != null) {
if (mp.isPlaying()) {
mp.stop();
}// End of if (mp.isPlaying())
}// End of if (mp != null)
}// End of back pressed
@Override
protected void onPause() {
super.onPause();
}// End of on pause method
@Override
protected void onStart() {
super.onStart();
}// End of on start method
@Override
protected void onResume() {
super.onResume();
}// End of on resume method
@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
onBackPressed();
finish();
return true;
}// End of onKeyDown method
// // Define method for choosing matching image
//
// void chooseImages() {
//
// }// End of choosing images
//
// // Define method for getting random values
//
// int getRandom(int value) {
//
// if (random == null) {
//
// random = new Random();
//
// }
//
// return random.nextInt(value);
//
// }// End of getRandom(int value) method
}// End of Animalsgame activity
I am using one sound button, and four image views. When i click the sound button, the sound get raised and simultaneously, imageviews are filled with images. But in phone when i run it. it shows error in some instance, when i click the sound button.
My part of java coding, in which i am working is mentioned above..
The error which i am getting is **Null pointer expection** and the error pointed out is in freezeButtonAndPlaySoundThenUnfreezeButton. Plz do me a needful..!
答案 0 :(得分：0)
我猜你错过了声音（第394行的mp变量为null）。你不应该在0和int randomInt = random.nextInt（tempSounds.size（））之间随机;因为没有元素和位置tempSounds.size（）。它应该是（tempSounds.size（） - 1）。