ImageUri 在将缩略图(位图)作为 onActivityResult 的意图传递时为 Null

Question

我已经困在这一行代码上好几天了。我有一个图像按钮，可以启动相机意图，保存照片，将照片的位图缩略图设置为图像按钮。我最终希望这张照片显示在谷歌地图标记信息窗口中。

这是我的报告活动，它启动相机意图并尝试将缩略图传递给 InfoWindow 类(该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，这是我的信息窗口类，我尝试接收此图像并将其设置为信息窗口。现在，InfoWindow可以显示ImageView，但由于ImageUri为Null，因此最好将其传递给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 启动活动 下所述，当您调用startActivityForResult()时，被调用的活动"可以选择返回包含它想要的任何其他数据的 Intent"。

您收到的错误消息指出传回的意向为 null，表示调用的活动未返回意向。

使用 MediaStore.ACTION_IMAGE_CAPTURE 调用的活动在其文档中未说明有关返回意向的任何内容。你认为有什么理由吗？

如果您需要从ACTION_IMAGE_CAPTURE活动中获取 imageUri，您可能需要将其存储在 SharedPreferences 或其他东西中，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。