java - 我的共享首选项无法正确共享

Question

我有一个应用程序，您可以将图像上传到我公司的服务器 因此，用户输入他们的登录详细信息、电子邮件、密码和 clientID(4 位代码)(在 LoginActivity.java 中)，然后必须将此信息传递给所有其他 Activity ，然后使用此传递的信息来构建 URL。现在我遇到的问题是 Sharedprefrences 无法正确共享...它们要么在 url 上显示为 NULL，要么只是“电子邮件”或“密码” 信息已正确保存在登录 Activity 中，但是当我尝试将其传递给其他 Activity 时，它失败了

在此处登录 Activity 我保存首选项

public class LoginActivity extends AppCompatActivity implements TextWatcher {


    SharedPreferences MyPrefs;
    Intent intent;
    SharedPreferences.Editor editor;
    public static final String PREF_NAME= "MYPREFS";
    public static final  String ID = "ClientID" ;
    public static final  String EMAIL = "username" ;
    public static final  String PASS = "password";

    EditText email, password, id;

    @SuppressLint("CommitPrefEdits")
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_login);
        Button buttonOne=findViewById(R.id.button);
        buttonOne.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {



                Intent activity2Intent=new Intent(getApplicationContext(), MainActivity.class);
                startActivity(activity2Intent);

    }
});

        MyPrefs= getSharedPreferences(PREF_NAME, 0);
        editor = MyPrefs.edit();


        email=findViewById(R.id.emailtext);
        password=findViewById(R.id.pwdtext);
        id=findViewById(R.id.clientid);

        email.setText(MyPrefs.getString(EMAIL,"username"));
        password.setText(MyPrefs.getString(PASS,"password"));
        id.setText(MyPrefs.getString(ID, "id"));
        email.addTextChangedListener(this);
        password.addTextChangedListener(this);
        id.addTextChangedListener(this);

        MyPrefs =getSharedPreferences(EMAIL,0);
        MyPrefs =getSharedPreferences(ID,0);
        MyPrefs =getSharedPreferences(PASS,0);
        intent = new Intent(LoginActivity.this,CameraActivity.class);


    }

    @Override
    public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) {

    }

    @Override
    public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) {
        managePrefs();
    }

    @Override
    public void afterTextChanged(Editable editable) {
managePrefs();

    }


    private void managePrefs(){
        SharedPreferences.Editor editor =MyPrefs.edit();

        editor.putString(EMAIL, email.getText().toString().trim());
        editor.putString(PASS, password.getText().toString().trim());
        editor.putString(ID, id.getText().toString().trim());

        editor.apply();

    }

    @Override
    public void onPointerCaptureChanged(boolean hasCapture) {

    }
}

相机 Activity ，这是共享首选项必须传递到的位置

public class CameraActivity extends AppCompatActivity implements View.OnClickListener {

    private final int PICK_IMAGE=12345;
    private final int REQUEST_CAMERA=6352;
    private static final int REQUEST_CAMERA_ACCESS_PERMISSION=5674;
    private Bitmap bitmap;

    String myURL;
    String email;
    String clientId;
    String pwd;




    private ImageView imageView;



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

我的调用共享首选项的代码

SharedPreferences sharedPreferences = getSharedPreferences(LoginActivity.PREF_NAME, 0);
         email = sharedPreferences.getString(LoginActivity.EMAIL, "username");
    clientId = sharedPreferences.getString(LoginActivity.ID, "id");
       pwd = sharedPreferences.getString(LoginActivity.PASS, "password");


        imageView=findViewById(R.id.imageView);
        Button fromCamera=findViewById(R.id.fromCamera);
        Button fromGallery=findViewById(R.id.fromGallery);
        Button upload=findViewById(R.id.upload);
        upload.setOnClickListener(this);
        fromCamera.setOnClickListener(this);
        fromGallery.setOnClickListener(this);
    }

    @Override
    public void onClick(View view) {



        switch (view.getId()) {
            case R.id.fromCamera:
                if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M
                        && ActivityCompat.checkSelfPermission(this, Manifest.permission.CAMERA)
                        != PackageManager.PERMISSION_GRANTED) {
                    requestPermissions(new String[]{Manifest.permission.CAMERA},
                            REQUEST_CAMERA_ACCESS_PERMISSION);
                } else {
                    getImageFromCamera();
                }
                break;
            case R.id.fromGallery:
                getImageFromGallery();
                break;
            case R.id.upload:
                if (bitmap != null)
                    uploadImageToServer();
                break;

        }


    }


    private void uploadImageToServer() {
        @SuppressLint("SimpleDateFormat") SimpleDateFormat dateFormat = new SimpleDateFormat("yyyyMMdd_HH_mm_ss");
        String currentTimeStamp = dateFormat.format(new Date());
        final ProgressDialog pd=new ProgressDialog(CameraActivity.this);
        pd.setMessage("Uploading, Please Wait....");
        pd.show();
        Intent intent = getIntent();
        String Item= intent.getStringExtra("Spinner");
        String Item2= intent.getStringExtra("Spinner2");


        Uri.Builder builder=new Uri.Builder();
        builder.scheme("https")
                .authority("www.smartpractice.co.za")
                .appendPath("files-upload-ruben.asp")
                .appendQueryParameter("MyForm", "Yes")
                .appendQueryParameter("ClientID",clientId)
                .appendQueryParameter("Username", email)
                .appendQueryParameter("Pwd", pwd)
        .appendQueryParameter("category",Item )
        .appendQueryParameter("client",Item2 );
        myURL=builder.build().toString();
        Toast toast = Toast.makeText(CameraActivity.this, myURL , Toast.LENGTH_LONG);
        toast.show();

        File imageFile=persistImage(bitmap,currentTimeStamp);

        Ion.with(this)
                .load(myURL)
                .uploadProgressDialog(pd)
                .setMultipartFile("SP-LOG", "image/jpeg", imageFile)


                .asString()


                .setCallback(new FutureCallback<String>() {
                    @Override
                    public void onCompleted(Exception e, String result) {
                     pd.cancel();
                        Toast.makeText(getApplicationContext(),"Uploaded",Toast.LENGTH_SHORT).show();

                    }
                });

    }

    private File persistImage(Bitmap bitmap, String name) {
        File filesDir=getApplicationContext().getFilesDir();
        File imageFile=new File(filesDir, name + ".jpg");

        OutputStream os;
        try {
            os=new FileOutputStream(imageFile);
            bitmap.compress(Bitmap.CompressFormat.JPEG, 100, os);
            os.flush();
            os.close();
        } catch (Exception e) {
            Log.e(getClass().getSimpleName(), "Error writing bitmap", e);
        }

        return imageFile;
    }


    private void getImageFromCamera() {
        Intent intent=new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
        startActivityForResult(intent, REQUEST_CAMERA);
    }

    private void getImageFromGallery() {
        Intent intent=new Intent();
        intent.setType("image/*");
        intent.setAction(Intent.ACTION_GET_CONTENT);
        if (intent.resolveActivity(getPackageManager()) != null) {
            startActivityForResult(Intent.createChooser(intent, "Select Picture"), PICK_IMAGE);
        }
    }

    @Override

    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if (requestCode == PICK_IMAGE) {
            if (resultCode == Activity.RESULT_OK) {
                try {
                    InputStream inputStream=getContentResolver().openInputStream(data.getData());
                    bitmap=BitmapFactory.decodeStream(inputStream);
                    imageView.setImageBitmap(bitmap);
                } catch (FileNotFoundException e) {
                    e.printStackTrace();
                }

            }
        } else if (requestCode == REQUEST_CAMERA) {
            if (resultCode == Activity.RESULT_OK) {
                Bundle extras=data.getExtras();
                bitmap=(Bitmap) extras.get("data");
                imageView.setImageBitmap(bitmap);
            }
        }
    }


    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
        if (requestCode == REQUEST_CAMERA_ACCESS_PERMISSION) {
            if (grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                getImageFromCamera();
            }
        } else {
            super.onRequestPermissionsResult(requestCode, permissions, grantResults);

        }
    }
}

Answer 1

要将数据存储在共享首选项中，请执行以下操作:

private SharedPreferences.Editor editor = getSharedPreferences(PREF_NAME, MODE_PRIVATE).edit();
                    editor.putString("email", email);
                    editor.putString("ID", id);
                    editor.putString("Pass", password);
                    editor.apply();

所以当你写 editor.putString("email", email); 时，我会给你一些解释。它告诉编辑器将您的电子邮件放在关键的“电子邮件”旁边。

现在，如果您想读回这些值，请执行以下操作:

String email = getSharedPreferences(PREF_NAME, MODE_PRIVATE).getString("email", "");
String ID= getSharedPreferences(PREF_NAME, MODE_PRIVATE).getString("ID", "");
String password= getSharedPreferences(PREF_NAME, MODE_PRIVATE).getString("Pass", "");

如果您不明白任何内容，请告诉我。