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在 Android Oreo 中調用相機意圖后,父活動正在重新創建

[英]Parent Activity is recreating after calling Camera intent in Android Oreo

我正在使用媒體意圖捕獲圖像。 處理完成后,結果將發送回父級。 上述過程在 Nougat Os 之前正常工作,但在 Oreo 中,父活動再次重新創建。 我該如何解決這個問題。

上述過程在 Nougat Os 之前正常工作,但在 Oreo 中,父活動再次重新創建

當相機應用程序在前台時,您的進程正在終止。 這是完全正常的,與 Android 8.0 無關。 它與可用的系統 RAM 以及當時設備中發生的一切有關。

我該如何解決這個問題。

沒有問題。 當您沒有前台 UI 時,您的進程可以隨時終止。 您的代碼需要處理這個問題。

例如,如果您在ACTION_IMAGE_CAPTURE Intent上使用EXTRA_OUTPUT ,則需要記住該值,因為您不會從相機應用程序以任何形式返回它。 將它保存在已保存的實例狀態Bundle是一個典型的解決方案,正如我在此示例應用程序中所說明的,特別是在此活動中:

/***
 Copyright (c) 2008-2017 CommonsWare, LLC
 Licensed under the Apache License, Version 2.0 (the "License"); you may not
 use this file except in compliance with the License. You may obtain a copy
 of the License at http://www.apache.org/licenses/LICENSE-2.0. Unless required
 by applicable law or agreed to in writing, software distributed under the
 License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS
 OF ANY KIND, either express or implied. See the License for the specific
 language governing permissions and limitations under the License.

 Covered in detail in the book _The Busy Coder's Guide to Android Development_
 https://commonsware.com/Android
 */

package com.commonsware.android.camcon;

import android.Manifest;
import android.app.Activity;
import android.content.ActivityNotFoundException;
import android.content.ClipData;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.content.pm.ResolveInfo;
import android.net.Uri;
import android.os.Build;
import android.os.Bundle;
import android.provider.MediaStore;
import android.support.v4.content.FileProvider;
import android.widget.Toast;
import java.io.File;
import java.util.List;

public class MainActivity extends Activity {
  private static final String EXTRA_FILENAME=
    "com.commonsware.android.camcon.EXTRA_FILENAME";
  private static final String FILENAME="CameraContentDemo.jpeg";
  private static final int CONTENT_REQUEST=1337;
  private static final String AUTHORITY=
    BuildConfig.APPLICATION_ID+".provider";
  private static final String PHOTOS="photos";
  private File output=null;

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

    if (savedInstanceState==null) {
      output=new File(new File(getFilesDir(), PHOTOS), FILENAME);

      if (output.exists()) {
        output.delete();
      }
      else {
        output.getParentFile().mkdirs();
      }

      Intent i=new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
      Uri outputUri=FileProvider.getUriForFile(this, AUTHORITY, output);

      i.putExtra(MediaStore.EXTRA_OUTPUT, outputUri);

      if (Build.VERSION.SDK_INT>=Build.VERSION_CODES.LOLLIPOP) {
        i.addFlags(Intent.FLAG_GRANT_WRITE_URI_PERMISSION);
      }
      else if (Build.VERSION.SDK_INT>=Build.VERSION_CODES.JELLY_BEAN) {
        ClipData clip=
          ClipData.newUri(getContentResolver(), "A photo", outputUri);

        i.setClipData(clip);
        i.addFlags(Intent.FLAG_GRANT_WRITE_URI_PERMISSION);
      }
      else {
        List<ResolveInfo> resInfoList=
          getPackageManager()
            .queryIntentActivities(i, PackageManager.MATCH_DEFAULT_ONLY);

        for (ResolveInfo resolveInfo : resInfoList) {
          String packageName = resolveInfo.activityInfo.packageName;
          grantUriPermission(packageName, outputUri,
            Intent.FLAG_GRANT_WRITE_URI_PERMISSION);
        }
      }

      try {
        startActivityForResult(i, CONTENT_REQUEST);
      }
      catch (ActivityNotFoundException e) {
        Toast.makeText(this, R.string.msg_no_camera, Toast.LENGTH_LONG).show();
        finish();
      }
    }
    else {
      output=(File)savedInstanceState.getSerializable(EXTRA_FILENAME);
    }
  }

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

    outState.putSerializable(EXTRA_FILENAME, output);
  }

  @Override
  protected void onActivityResult(int requestCode, int resultCode,
                                  Intent data) {
    if (requestCode == CONTENT_REQUEST) {
      if (resultCode == RESULT_OK) {
        Intent i=new Intent(Intent.ACTION_VIEW);
        Uri outputUri=FileProvider.getUriForFile(this, AUTHORITY, output);

        i.setDataAndType(outputUri, "image/jpeg");
        i.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);

        try {
          startActivity(i);
        }
        catch (ActivityNotFoundException e) {
          Toast.makeText(this, R.string.msg_no_viewer, Toast.LENGTH_LONG).show();
        }

        finish();
      }
    }
  }
}

在這里,我在保存的實例狀態Bundle保持output位置,因此即使我的進程終止,我也會恢復我的output

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