Android8.0版本更新无法自动安装问题的解决方法

 if (Build.VERSION.SDK_INT >= 26) { 
    //来判断应用是否有权限安装apk
    boolean installAllowed= getPackageManager().canRequestPackageInstalls(); 
    //有权限
    if (installAllowed) { 
      //安装apk
      install(apkPath);
    } else { 
      //无权限 申请权限
      ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.REQUEST_INSTALL_PACKAGES}, INSTALL_APK_REQUESTCODE); 
    } 
  } else { 
    install(apkPath); 
} 

@Override 
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) { 
  super.onRequestPermissionsResult(requestCode, permissions, grantResults); 
  switch (requestCode) { 
    case INSTALL_APK_REQUESTCODE: 
      //有注册权限且用户允许安装
      if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) { 
        install(apkPath); 
      } else { 
        //将用户引导至安装未知应用界面。
        Intent intent = new Intent(Settings.ACTION_MANAGE_UNKNOWN_APP_SOURCES); 
        startActivityForResult(intent, GET_UNKNOWN_APP_SOURCES); 
      } 
      break; 

  } 
} 

private void install(String apkPath) {
    //7.0以上通过FileProvider
    if (Environment.SYSTEM_VERSION_CODE >= 24) {
      Uri uri = FileProvider.getUriForFile(context, Environment.FILE_PROVIDER_AUTHORITY, new File(apkPath));
      Intent intent = new Intent(Intent.ACTION_VIEW).setDataAndType(uri, "application/vnd.android.package-archive");
      intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
      intent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
      context.startActivity(intent);
    } else {
      Intent intent = new Intent(Intent.ACTION_VIEW);
      intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
      intent.setDataAndType(Uri.parse("file://" + apkPath), "application/vnd.android.package-archive");
      context.startActivity(intent);
    }
}