java - 将缩略图(位图)作为 onActivityResult 的 Intent 传递时，ImageUri 为 Null

Question

我已经被这行代码困住了好几天了。我有一个 ImageButton，它启动相机 Intent ，保存照片，将照片的位图缩略图设置到 ImageButton。我最终希望这张照片显示在 Google map 标记信息窗口中。

这是我的报告 Activity ，它启动相机 Intent 并尝试将缩略图传递给 InfoWindow 类(在信息窗口中为标记创建内容)

import android.app.Activity;
import android.content.ContentValues;
import android.content.Intent;
import android.database.Cursor;
import android.graphics.Bitmap;
import android.location.Location;
import android.net.Uri;
import android.os.Build;
import android.os.Bundle;
import android.provider.MediaStore;
import android.support.annotation.RequiresApi;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ImageButton;
import android.widget.ImageView;
import android.widget.ProgressBar;
import android.widget.Spinner;
import android.widget.TextView;

import com.google.android.gms.location.FusedLocationProviderClient;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.model.LatLng;

public class FoundPetReport extends AppCompatActivity {
    public GoogleMap mMap;
    public static final int REQUEST_TAKE_PHOTO = 1;
    public static final int SCREEN_ORIENTATION_LANDSCAPE = 0;
    private Spinner spinner1, spinner2;
    private ImageButton imageButton;
    private Button buttonLocation;
    private Button btnSubmit;
    private ImageButton btnCamera;
    private ImageView imageViewCamera;
    private TextView place_details;
    static final int REQUEST_IMAGE_CAPTURE = 1;
    private String s;
    public Uri imageUri;
    public Object imageurl;
    public static final int PICTURE_RESULT = 0;


    private static final String TAG = FoundPetReport.class.getSimpleName();

    private static final int REQUEST_PERMISSIONS_REQUEST_CODE = 34;

    private static final String ADDRESS_REQUESTED_KEY = "address-request-pending";
    private static final String LOCATION_ADDRESS_KEY = "location-address";

    /**
     * Provides access to the Fused Location Provider API.
     */
    private FusedLocationProviderClient mFusedLocationClient;


    /**
     * Represents a geographical location.
     */
    public Location mLastLocation;

    /**
     * Tracks whether the user has requested an address. Becomes true when the user requests an
     * address and false when the address (or an error message) is delivered.
     */
    private boolean mAddressRequested;

    /**
     * The formatted location address.
     */
    private String mAddressOutput;

    /**
     * Receiver registered with this activity to get the response from FetchAddressIntentService.
     */

    /**
     * Displays the location address.
     */
    private TextView mLocationAddressTextView;
    private FusedLocationProviderClient mFusedLocationProviderClient;

    /**
     * Visible while the address is being fetched.
     */
    private ProgressBar mProgressBar;

    /**
     * Kicks off the request to fetch an address when pressed.
     */
    private Button mFetchAddressButton;

    String newaddress;

    public LatLng location;
    private LatLng position;



    @RequiresApi(api = Build.VERSION_CODES.M)
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.foundpet);

        addListenerOnButton();
        addListenerOnSpinnerItemSelection();


        ContentValues values = new ContentValues();
        values.put(MediaStore.Images.Media.TITLE, "New Picture");
        values.put(MediaStore.Images.Media.DESCRIPTION, "From your Camera");
        imageUri = getContentResolver().insert(
                MediaStore.Images.Media.EXTERNAL_CONTENT_URI, values);
        Log.d("imageUri", String.valueOf(imageUri));

        if (savedInstanceState == null) {
            Bundle extras = getIntent().getExtras();
            if (extras == null) {
                newaddress = null;
                location = null;
            } else {
                newaddress = extras.getString("address");
                location = extras.getParcelable("location");

            }
        } else {
            newaddress = (String) savedInstanceState.getSerializable("address");
            location = (LatLng) savedInstanceState.getParcelable("location");
        }
        newaddress = getIntent().getStringExtra("address");
        TextView place_details = (TextView) findViewById(R.id.place_details);
        place_details.setText(newaddress);


        ImageButton imageButton = (ImageButton) findViewById(R.id.imageButton);
        imageButton.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View view) {
                Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
                intent.putExtra(MediaStore.EXTRA_OUTPUT, imageUri);
                startActivityForResult(intent, PICTURE_RESULT);
            }
        });
    }

    // add items into spinner dynamically

    public void addListenerOnSpinnerItemSelection() {
        spinner1 = (Spinner) findViewById(R.id.spinner1);
        spinner1.setOnItemSelectedListener(new CustomOnItemSelectedListener());
    }

    // get the selected dropdown list value
    public void addListenerOnButton() {

        spinner1 = (Spinner) findViewById(R.id.spinner1);
        spinner2 = (Spinner) findViewById(R.id.spinner2);
        btnSubmit = (Button) findViewById(R.id.btnSubmit);

        btnSubmit.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                Intent intent2 = new Intent(FoundPetReport.this, NewReportedMarkerFound.class);
                intent2.putExtra("address", newaddress);
                startActivity(intent2);
            }
        });
    }

    @Override
    protected void onSaveInstanceState(Bundle outState) {
        super.onSaveInstanceState(outState);

        outState.putParcelable("imageUri", imageUri);
    }


    protected void onActivityResult(int requestCode, int resultCode, Intent intent) {

        ImageButton imageButton = (ImageButton) findViewById(R.id.imageButton);
        switch (requestCode) {

            case PICTURE_RESULT:
                if (resultCode == Activity.RESULT_OK) {
                    try {

                        Bitmap thumbnail = MediaStore.Images.Media.getBitmap(
                                getContentResolver(), imageUri);
                        Log.d("thumbnail", String.valueOf(thumbnail.getWidth() + " " + thumbnail.getHeight()));
                        imageButton.setImageBitmap(thumbnail);
                        imageurl = getRealPathFromURI(imageUri);
                        Log.d("imageurl", imageurl.toString());
                        imageUri = intent.getData();

                        Intent photoIntent = new Intent(FoundPetReport.this, CustomInfoWindowAdapter.class);
                        photoIntent.putExtra("photo", thumbnail);

                        startActivity(photoIntent);


                    } catch (Exception e) {
                        e.printStackTrace();
                    }

                }
        }

    }


    public String getRealPathFromURI(Uri contentUri) {
        String[] proj = {MediaStore.Images.Media.DATA};
        Cursor cursor = managedQuery(contentUri, proj, null, null, null);
        int column_index = cursor
                .getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
        cursor.moveToFirst();
        return cursor.getString(column_index);
    }

}

错误:

D/thumbnail: 4032 2268
D/imageurl: /storage/emulated/0/Pictures/1528830788205.jpg
W/System.err: java.lang.NullPointerException: Attempt to invoke virtual method 'android.net.Uri android.content.Intent.getData()' on a null object reference
W/System.err:     at com.example.barperetz.petfinder.FoundPetReport.onActivityResult(FoundPetReport.java:198)
W/System.err:     at android.app.Activity.dispatchActivityResult(Activity.java:7226)
W/System.err:     at android.app.ActivityThread.deliverResults(ActivityThread.java:4521)
W/System.err:     at android.app.ActivityThread.handleSendResult(ActivityThread.java:4568)
W/System.err:     at android.app.ActivityThread.-wrap22(ActivityThread.java)
W/System.err:     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1706)
W/System.err:     at android.os.Handler.dispatchMessage(Handler.java:102)
W/System.err:     at android.os.Looper.loop(Looper.java:154)
W/System.err:     at android.app.ActivityThread.main(ActivityThread.java:6688)
W/System.err:     at java.lang.reflect.Method.invoke(Native Method)
W/System.err:     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1468)
W/System.err:     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1358)

为了清楚起见，这是我的 InfoWindow 类，我尝试在其中接收此图像并将其设置为 InfoWindow。现在，InfoWindow 可以显示 ImageView，但由于 ImageUri 为 Null，所以最好将其传递给 InfoWindow:

import android.app.Activity;
import android.graphics.Bitmap;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.View;
import android.widget.ImageView;
import android.widget.TextView;

import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.model.Marker;


public class CustomInfoWindowAdapter extends AppCompatActivity implements GoogleMap.InfoWindowAdapter {


    private Activity context;
    public Bitmap thumbnail;
    public ImageView windowImage;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        if (savedInstanceState == null) {
            Bundle extras = getIntent().getExtras();
            if (extras == null) {
                thumbnail = null;
            } else {
                thumbnail = extras.getParcelable("photo");
            }
            } else {
                thumbnail = (Bitmap) savedInstanceState.getParcelable("photo");

            }
        thumbnail = (Bitmap) getIntent().getExtras().get("photo");
        Log.d("thumbnailtwo", String.valueOf(thumbnail));
        }


    public CustomInfoWindowAdapter(Activity context){
        this.context = context;

    }

    @Override
    public View getInfoWindow(Marker marker) {
        return null;
    }

    @Override
    public View getInfoContents(Marker marker) {

        View view = context.getLayoutInflater().inflate(R.layout.custominfowindow, null);

        TextView tvTitle = (TextView) view.findViewById(R.id.pet_name);
        TextView tvSubTitle = (TextView) view.findViewById(R.id.pet_address);
        ImageView windowImage = (ImageView) view.findViewById(R.id.windowImage);

        windowImage.setImageBitmap(thumbnail);
        tvTitle.setText(marker.getTitle());
        tvSubTitle.setText(marker.getSnippet());

        return view;
    }
}

Answer 1

如 Starting Activities 下所述，当您调用 startActivityForResult() 时，被调用的 Activity “可以可选返回包含它想要的任何附加数据的 Intent。”

您收到的错误消息表明传回的 Intent 为空，表明被调用的 Activity 未返回 Intent 。

您正在调用的 Activity ，使用 MediaStore.ACTION_IMAGE_CAPTURE ，在其文档中没有提及任何有关返回 Intent 的内容。您认为应该有什么理由吗？

如果您需要从 ACTION_IMAGE_CAPTURE Activity 中获取 imageUri，您可能需要将其存储在 SharedPreferences 或其他内容中，并通过 requestCode 参数传递它的索引或哈希，以便您可以在返回时恢复它。