Question

我已经研究过this代码，并在应用中使用并且工作正常。但我的问题是，我认为意图始于放置在抽屉中的imegView的longClick事件。当我将代码放在MainActivity中时，我在图像视图上收到一个null点execption，所以我创建了一个像这样的新视图：

View view = LayoutInflater.from(getApplication()).inflate(R.layout.first_item, null);

但事件并没有开始。我无法将代码放在适配器中，因为我需要一个扩展＆＃34; Activity＆＃34;否则意图确实有效。

这是我的完整代码：

public class MainActivity extends Activity {

private static int PICK_IMAGE_REQUEST = 101;
private ImageView selectedImagePreview;
private DrawerLayout mDrawerLayout;
static ListView mDrawerList;
final String GREEN = "7f0b3452";
private static int itemInteger = 0;
int itemStatusInteger = 0;
DrawerItem dItem;
private static String newConsolName;
AddItem addItem = new AddItem();
static CustomDrawerAdapter adapter;
static List<DrawerItem> dataList;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    View view = LayoutInflater.from(getApplication()).inflate(R.layout.first_item, null);
    selectedImagePreview = (ImageView)view.findViewById(R.id.imageView);
    selectedImagePreview.setOnLongClickListener(new View.OnLongClickListener() {
        @Override
        public boolean onLongClick(View v) {
            startGalleryIntent();
            return false;
        }
    });

    // Initializing
    dataList = new ArrayList<DrawerItem>();
    mDrawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
    mDrawerList = (ListView) findViewById(R.id.left_drawer);

    // Add Drawer Item to dataList
    dataList.add(new DrawerItem(R.mipmap.ps4miniatura, GREEN, 1));

    dataList.add(new DrawerItem(R.mipmap.ps4miniatura, "PC", 0));
    dataList.add(new DrawerItem(R.mipmap.ps4miniatura, "PC", 0));
    dataList.add(new DrawerItem(R.mipmap.ps4miniatura, "PC", 0));
    dataList.add(new DrawerItem(R.mipmap.ps4miniatura, "PC", 0));
    dataList.add(new DrawerItem(R.mipmap.ps4miniatura, "PC", 0));

    dataList.add(new DrawerItem(0, " ", 2));

    adapter = new CustomDrawerAdapter(this, R.layout.custom_drawer_item, adapter,
            dataList);

 //   addItem.giveAdapter(adapter);
    mDrawerList.setAdapter(adapter);
    mDrawerList.setChoiceMode(ListView.CHOICE_MODE_MULTIPLE);
    mDrawerList.setOnItemClickListener(new DrawerItemClickListener());

    if (savedInstanceState == null) {
        SelectItem(1);
    }
}

public void SelectItem(int possition) {

    Fragment fragment = null;
    Bundle args = new Bundle();

    switch (possition) {
        case 1:
            fragment = new Fragment1();
            break;
        case 2:
            fragment = new Fragment2();
            break;
        case 3:
            fragment = new Fragment3();
            break;
        case 4:
            fragment = new Fragment4();
            break;


        default:
            break;
        }

    FragmentManager frgManager = getFragmentManager();
    frgManager.beginTransaction().replace(R.id.content_frame, fragment)
            .commit();

    mDrawerList.setItemChecked(possition, true);
    setTitle(dataList.get(possition).getItemName());
    mDrawerLayout.closeDrawer(mDrawerList);

}

private class DrawerItemClickListener implements
        ListView.OnItemClickListener {
    @Override
    public void onItemClick(AdapterView<?> parent, View view, int position,
                            long id) {
        if ( dataList.get(position).getVersion() == 0) {
            SelectItem(position);
        }  else {
        }
    }
}

public void startGalleryIntent(){
    Intent intent = new Intent();
    intent.setType("image/*");
    intent.setAction(Intent.ACTION_GET_CONTENT);
    startActivityForResult(Intent.createChooser(intent, "Select Picture"), PICK_IMAGE_REQUEST);
}

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    if (resultCode == RESULT_OK) {
        Uri selectedImageUri = data.getData();
        try {
            selectedImagePreview.setImageBitmap(new UserPicture(selectedImageUri, getContentResolver()).getBitmap());
        } catch (IOException e) {
            Log.e(MainActivity.class.getSimpleName(), "Failed to load image", e);
        }
    }
}
public String getPath(Uri uri) {

    // just some safety built in
    if( uri == null ) {
        // perform some logging or show user feedback
        Toast.makeText(getApplicationContext(), "false", Toast.LENGTH_LONG).show();
        Log.d(MainActivity.class.getSimpleName(), "Failed to parse image path from image URI " + uri);
        return null;
    }

    String[] projection = { MediaStore.Images.Media.DATA };
    Cursor cursor = managedQuery(uri, projection, null, null, null);
    if( cursor != null ){
        int column_index = cursor
                .getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
        cursor.moveToFirst();
        return cursor.getString(column_index);
    }
    return uri.getPath();
}
}

我该怎么办？

Answer 1

嗯，首先，您正在为新视图充气，但却没有使用your_layout.addView（查看）将其添加到现有布局中。

但由于这是主要问题的解决方法，因此适当的解决方案可能类似于适配器中的回调接口。像这样 - Callbacks between classes

从DrawerMenu启动Gallery Intent。零点异常

1 个答案: