【发布时间】：2019-08-16 06:13:16
【问题描述】：
我有一个应用程序，您可以在其中将图像上传到我的公司服务器 因此，用户输入他们的登录详细信息、电子邮件、密码和客户端 ID（4 位代码）（在 LoginActivity.java 中），然后必须将此信息传递给所有其他活动，然后使用此传递的信息来构建 URL。现在我遇到的问题是 Sharedprefrences 没有正确共享......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活动中，但是当我尝试将其传递给其他活动时失败
登录活动在这里我保存了偏好
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) {
}
}
Camera Activity 这是必须将共享偏好传递给的地方
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);
我调用 sharedprefrences 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);
}
}
}
【问题讨论】：
-
你为什么叫这个代码行？ MyPrefs =getSharedPreferences(EMAIL,0); MyPrefs =getSharedPreferences(ID,0); MyPrefs =getSharedPreferences(PASS,0);
-
我只编写了 2 周的代码，这是我试图调用这些信息的尝试......我真的不知道...... :]
-
“当我尝试将它传递给其他活动时它失败了”是什么意思。你的意思是，你不能从 sharedPreference 中获得价值？
-
@Kabir，是的，我使用 sharedprefrences 来构建带有 URI 的 URL。 builder 所以当信息被传递时，我的 URL 中会出现 NULL
-
检查一下 sharedPrefernece:abhiandroid.com/programming/shared-preference
标签： java android android-activity sharedpreferences