我正在开发一个项目，我比较两个项目的图像，所以如果两个项目在点击这些项目后将具有相同的图像应该隐藏。我的代码如下所示，此代码遇到问题。这是一个逻辑错误还是任何其他问题？我试着解决这个问题，但没有解决..请指导我......这是我的主要活动 MainActivity.java
public class MainActivity extends Activity {
Context ctx;
int imagesArray[];
ImageAdapter adapter;
List<Integer> pictures;
boolean flage = false;
GridView gridView;
int save1, save2;
int img1 = -1, img2 = -1;
public int OriginalArray[] = { R.drawable.sample_0, R.drawable.sample_1,
R.drawable.sample_2, R.drawable.sample_3, R.drawable.sample_0,
R.drawable.sample_1, R.drawable.sample_2, R.drawable.sample_3 };
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
final ImageView myimage = new ImageView(ctx);
gridView = (GridView) findViewById(R.id.gv_memory);
gridView.setAdapter(adapter);
shuffleArray();
gridView.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> arg0, View arg1,
int position, long arg3) {
// TODO Auto-generated method stub
myimage.setImageResource(pictures.get(position));
if (flage == false) {
img1 = pictures.get(position);
flage = true;
} else if (flage == true) {
img2 = pictures.get(position);
checkResult();
flage = false;
}
}
private void checkResult() {
// TODO Auto-generated method stub
if (img1 == img2) {
adapter.pictureList.remove(img1);
adapter.pictureList.remove(img2);
adapter.notifyDataSetChanged();
Toast.makeText(MainActivity.this, "Congratualatin !!!!",
Toast.LENGTH_LONG).show();
} else {
Toast.makeText(MainActivity.this, "Sorry!!!!",
Toast.LENGTH_LONG).show();
}
}
});
}
private void shuffleArray() {
// TODO Auto-generated method stub
pictures = new ArrayList<Integer>();
for (int index = 0; index < OriginalArray.length; index++) {
pictures.add(OriginalArray[index]);
}
Collections.shuffle(pictures);
}
}
ImageAdapter.java
public class ImageAdapter extends BaseAdapter {
private Context context;
List<Integer> pictureList = new ArrayList<Integer>();
public ImageAdapter(Context c) {
context = c;
for (int i = 0; i < 8; i++) {
pictureList.add(R.drawable.question);
}
}
@Override
public int getCount() {
// TODO Auto-generated method stub
return (pictureList.size());
}
@Override
public Object getItem(int position) {
// TODO Auto-generated method stub
return pictureList.get(position);
}
@Override
public long getItemId(int position) {
// TODO Auto-generated method stub
return position;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
// TODO Auto-generated method stub
ImageView myimage = new ImageView(context);
myimage.setImageResource(pictureList.get(position));
myimage.setScaleType(ImageView.ScaleType.CENTER_INSIDE);
myimage.setLayoutParams(new GridView.LayoutParams(70, 70));
return myimage;
}
}
logcat的。
03-14 06:09:03.793: D/dalvikvm(2877): GC_FOR_ALLOC freed 54K, 8% free 2771K/2996K, paused 111ms, total 117ms
03-14 06:09:03.802: I/dalvikvm-heap(2877): Grow heap (frag case) to 3.943MB for 1127536-byte allocation
03-14 06:09:03.922: D/dalvikvm(2877): GC_FOR_ALLOC freed 2K, 6% free 3870K/4100K, paused 118ms, total 118ms
03-14 06:09:03.962: D/AndroidRuntime(2877): Shutting down VM
03-14 06:09:03.962: W/dalvikvm(2877): threadid=1: thread exiting with uncaught exception (group=0x41465700)
03-14 06:09:03.972: E/AndroidRuntime(2877): FATAL EXCEPTION: main
03-14 06:09:03.972: E/AndroidRuntime(2877): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.memory/com.example.memory.MainActivity}: java.lang.NullPointerException
03-14 06:09:03.972: E/AndroidRuntime(2877): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2211)
03-14 06:09:03.972: E/AndroidRuntime(2877): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2261)
03-14 06:09:03.972: E/AndroidRuntime(2877): at android.app.ActivityThread.access$600(ActivityThread.java:141)
03-14 06:09:03.972: E/AndroidRuntime(2877): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1256)
03-14 06:09:03.972: E/AndroidRuntime(2877): at android.os.Handler.dispatchMessage(Handler.java:99)
03-14 06:09:03.972: E/AndroidRuntime(2877): at android.os.Looper.loop(Looper.java:137)
03-14 06:09:03.972: E/AndroidRuntime(2877): at android.app.ActivityThread.main(ActivityThread.java:5103)
03-14 06:09:03.972: E/AndroidRuntime(2877): at java.lang.reflect.Method.invokeNative(Native Method)
03-14 06:09:03.972: E/AndroidRuntime(2877): at java.lang.reflect.Method.invoke(Method.java:525)
03-14 06:09:03.972: E/AndroidRuntime(2877): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737)
03-14 06:09:03.972: E/AndroidRuntime(2877): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
03-14 06:09:03.972: E/AndroidRuntime(2877): at dalvik.system.NativeStart.main(Native Method)
03-14 06:09:03.972: E/AndroidRuntime(2877): Caused by: java.lang.NullPointerException
03-14 06:09:03.972: E/AndroidRuntime(2877): at android.view.ViewConfiguration.get(ViewConfiguration.java:318)
03-14 06:09:03.972: E/AndroidRuntime(2877): at android.view.View.<init>(View.java:3264)
03-14 06:09:03.972: E/AndroidRuntime(2877): at android.widget.ImageView.<init>(ImageView.java:112)
03-14 06:09:03.972: E/AndroidRuntime(2877): at com.example.memory.MainActivity.onCreate(MainActivity.java:33)
03-14 06:09:03.972: E/AndroidRuntime(2877): at android.app.Activity.performCreate(Activity.java:5133)
03-14 06:09:03.972: E/AndroidRuntime(2877): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
03-14 06:09:03.972: E/AndroidRuntime(2877): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2175)
03-14 06:09:03.972: E/AndroidRuntime(2877): ... 11 more
03-14 06:14:04.503: I/Process(2877): Sending signal. PID: 2877 SIG: 9
答案 0 :(得分：1)
你有
final ImageView myimage = new ImageView(ctx);
ctz未初始化。它只被声明为Context ctx;
你有这个
gridView.setAdapter(adapter);
但是在使用相同的
之前，你需要初始化adapter
所以改为
setContentView(R.layout.main);
final ImageView myimage = new ImageView(this); //this refers to Activity context
gridView = (GridView) findViewById(R.id.gv_memory);
adapter = new ImageAdapter(this)
gridView.setAdapter(adapter);