java - 全屏图像上的 ViewFlipper

Question

抱歉我的英语不好。我有一个画廊，当您单击特定图像时，它会出现在屏幕上。当图片占满整个屏幕时，我想做什么，它仍然可以滚动。为此，我使用 ViewFlipper。主要 Activity

    public class MainAcTwo extends Activity {

@SuppressWarnings("deprecation")
Gallery gallery;
ImageView bigimage;

@SuppressWarnings("deprecation")
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.two);
    gallery=(Gallery) findViewById(R.id.gallery);
    gallery.setAdapter(new ImageAdapter(this));

    gallery.setOnItemClickListener(new OnItemClickListener() {
        @TargetApi(Build.VERSION_CODES.HONEYCOMB) @SuppressLint("NewApi") public void onItemClick(AdapterView<?> parent, View v,
                int position, long id) {

            long imageId = ImageAdapter.ThumbsIds[position];

           Intent fullScreenIntent = new Intent(v.getContext(), FullScreenImage.class);
           fullScreenIntent.putExtra(MainAcTwo.class.getName(), imageId);

          MainAcTwo.this.startActivity(fullScreenIntent); 

        }
    });
}}

图像适配器

    public class ImageAdapter extends BaseAdapter implements SpinnerAdapter {

private Context context;

public ImageAdapter(Context context) {
    // TODO Auto-generated constructor stub
    this.context = context;
}

@Override
public int getCount() {
    // TODO Auto-generated method stub
    return ThumbsIds.length;
}

@Override
public Object getItem(int arg0) {
    // TODO Auto-generated method stub
    return null;
}

@Override
public long getItemId(int arg0) {
    // TODO Auto-generated method stub
    return 0;
}

@Override
public View getView(final int position, View convertView, ViewGroup arg2) {
    // TODO Auto-generated method stub
    ImageView imageView=null;
    if(convertView == null) {
        imageView = new ImageView(context);
        imageView.setLayoutParams(new Gallery.LayoutParams(215, 200));
        imageView.setPadding(8, 8, 8, 8);


    }else {
        imageView = (ImageView) convertView;
    }

    imageView.setImageResource(ThumbsIds[position]);

    return imageView;
}

public static Integer[] ThumbsIds={
    R.drawable.abs_icla,
    R.drawable.abs_dog,
    R.drawable.abs_flow,
    R.drawable.abs_neb,
    R.drawable.abs_rad
};
}

全屏图像

public class FullScreenImage extends Activity {

private ViewFlipper flipper = null;
private float fromPosition;

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);   
    setContentView(R.layout.full_image);

    Intent intent = getIntent();
    long imageId = (Long) intent.getExtras().get(FullScreenImage.class.getName());
    LinearLayout mainLayout = (LinearLayout) findViewById(R.id.main_layout);
    mainLayout.setOnTouchListener((OnTouchListener) this);
    ImageView imageView = (ImageView) findViewById(R.id.imageView1);

    imageView.setLayoutParams( new ViewFlipper.LayoutParams(WindowManager.LayoutParams.MATCH_PARENT, WindowManager.LayoutParams.MATCH_PARENT));

    imageView.setImageResource((int) imageId);
    imageView.setScaleType(ImageView.ScaleType.FIT_XY);

    flipper = (ViewFlipper) findViewById(R.id.fullImage);
    LayoutInflater inflater = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);

    flipper.showNext();




}

public boolean onTouch(View view, MotionEvent event)
{
    switch (event.getAction())
    {
    case MotionEvent.ACTION_DOWN: 
        fromPosition = event.getX();
        break;
    case MotionEvent.ACTION_UP: 
        float toPosition = event.getX();
        if (fromPosition > toPosition)
            flipper.showNext();
        else if (fromPosition < toPosition)
            flipper.showPrevious();
    default:
        break;
    }
    return true;
}

}

在logCat中

09-22 18:49:19.941: E/AndroidRuntime(1321): FATAL EXCEPTION: main 09-22 18:49:19.941: E/AndroidRuntime(1321): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.kruglick/com.example.kruglick.FullScreenImage}: java.lang.NullPointerException 09-22 18:49:19.941: E/AndroidRuntime(1321): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2059) 09-22 18:49:19.941: E/AndroidRuntime(1321): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2084) 09-22 18:49:19.941: E/AndroidRuntime(1321): at android.app.ActivityThread.access$600(ActivityThread.java:130) 09-22 18:49:19.941: E/AndroidRuntime(1321): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1195) 09-22 18:49:19.941: E/AndroidRuntime(1321): at android.os.Handler.dispatchMessage(Handler.java:99) 09-22 18:49:19.941: E/AndroidRuntime(1321): at android.os.Looper.loop(Looper.java:137)

我的 full_image.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/main_layout"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >


        <ViewFlipper
            android:id="@+id/fullImage"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content" >

         <ImageView
           android:id="@+id/imageView1"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
             />   

         </ViewFlipper>


</LinearLayout>

Answer 1

实际上我在你的代码中发现了两个错误。

1) 您正在使用类名“MainAcTwo.class.getName()”将额外内容设置为 Intent ，并尝试使用类名“FullScreenImage.class.getName()”获取额外内容。

将 FullScreenImage Activity 中的代码更改为

long imageId = (Long) intent.getExtras().get(MainAcTwo.class.getName());

2) 在“FullScreenImage” Activity 中实现OnTouchListener接口(interface)。

进行这些更改后，您的代码可以正常工作而不会崩溃。