Android应用程序不会从登录或注册活动中转到下一个活动

Question

当我尝试通过按下注册页面中的sign_up或在用户已经存在的情况下登录日志页面进入下一个活动时，应用程序只是退出并带来一个错误。

注册活动//变量最终字符串TAG ="signUp";private MaterialEditText edit_name;private MaterialEditText;

//DECLARING & INITIALISING BUTTON TO SIGN UP
FButton sign_Up;

final String KEY_NAME = "name";
final String KEY_PASSWORD ="password";
final String KEY_MARKS ="marks";

private FirebaseFirestore db = FirebaseFirestore.getInstance();
private DocumentReference user_reference = db.document("Users/Users details");
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.sign_up);
//INITIALISING THE EDITTEXT VIEWS
edit_name = findViewById(R.id.editName);
edit_password = findViewById(R.id.editPassword);
sign_Up = findViewById(R.id.btn_signUp);
sign_Up.setOnClickListener(view ->
{
user_reference.get()
.addOnSuccessListener(new OnSuccessListener<DocumentSnapshot>()
{
Map<String, Object> users = new HashMap<>();
String name = edit_name.getText().toString();
String password = edit_password.getText().toString();
@Override
public void onSuccess(DocumentSnapshot documentSnapshot)
{
if(documentSnapshot.exists())
{ // GETTING INFORMATION FROM FIRESTORE DATABASE
name = documentSnapshot.getString(KEY_NAME);
password = documentSnapshot.getString(KEY_PASSWORD);
Toast.makeText(sign_up.this, "This user already exist, Try again", Toast.LENGTH_LONG).show();
}
else
{
users.put(KEY_NAME,name);
users.put(KEY_PASSWORD, password);
db.collection("Users").document(name).set(users);
Toast.makeText(sign_up.this,"Registered",Toast.LENGTH_LONG).show();
Intent i = new Intent(sign_up.this,sum_selection.class);
startActivity(i);
}

}// END OF ONSUCCESS
})
.addOnFailureListener(new OnFailureListener()
{
@Override
public void onFailure(@NonNull Exception e)
{
Toast.makeText(sign_up.this, "Error",Toast.LENGTH_LONG).show();
Log.d(TAG,e.toString());
}
});

登录活动

private MaterialEditText user_name;
private MaterialEditText user_password;
FButton sign_in;
private FirebaseFirestore database = FirebaseFirestore.getInstance();
private DocumentReference user_reference = database.document("Users/users details");
final String KEY_NAME = "name";
final String KEY_PASSWORD = "password";
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.login);
sign_in = findViewById(R.id.btn_sign_in);

sign_in.setOnClickListener(new View.OnClickListener()
{
@Override
public void onClick(View view)  // log in button
{
user_reference.get()
.addOnSuccessListener(new OnSuccessListener<DocumentSnapshot>()
{
@Override
public void onSuccess(DocumentSnapshot documentSnapshot)
{
if(documentSnapshot.exists())
{
Toast.makeText(log_in.this,"Welcome"+ user_name, Toast.LENGTH_LONG).show();
// ADD INTENT TO GO TO THE SUM_SELECTION PAGE
Intent in = new Intent(log_in.this, sum_selection.class);
startActivity(in);
}
else
{
// DISPLAY ERROR MESSAGE TO USER
Toast.makeText(log_in.this, "User does not exist", Toast.LENGTH_LONG).show();
}
}
})
.addOnFailureListener(new OnFailureListener()
{
@Override
public void onFailure(@NonNull Exception e)
{
Log.d(TAG, e.toString());
}
}); ```


[Error message][1]

[1]: https://i.stack.imgur.com/8gR62.png

Answer 1

Intent i = new Intent((this/activity),LoginActivity.class);
(this/activity).startActivity(i);

正确检查你的意图，意图将当前活动作为第一个参数，你想要加载的活动作为第二个参数。另外，从activity context中调用startActivity(i)，因为当前您处于Firebase Listener的上下文中。

同时，发布错误日志。