所以基本上这是我的例子
活动A，B和C。
假设我想将变量从A发送到C，同时打开活动B。我当时在考虑多个意图，但这似乎行不通。请帮一个简单的例子。
“活动A”
package com.example.munaseribrahimewallet;
import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import android.app.DatePickerDialog;
import android.content.SharedPreferences;
import android.view.MotionEvent;
import android.view.View;
import android.content.Intent;
import android.os.Bundle;
import android.text.TextUtils;
import android.util.Patterns;
import android.widget.Button;
import android.widget.DatePicker;
import android.widget.EditText;
import android.widget.ProgressBar;
import android.widget.TextView;
import android.widget.Toast;
import com.google.android.gms.tasks.OnCompleteListener;
import com.google.android.gms.tasks.Task;
import com.google.firebase.auth.AuthResult;
import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.database.DataSnapshot;
import com.google.firebase.database.DatabaseError;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
import com.google.firebase.database.ValueEventListener;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.regex.Pattern;
public class SignUpActivity extends AppCompatActivity{
//we will use these constants later to pass the Member name and id to another activity
public static final String EXTRA_EMAIL = "com.example.munaseribrahimewallet.EXTRA_NAME";
private DatePickerDialog mDatePickerDialog;
private static final Pattern PASSWORD_PATTERN =
Pattern.compile("^" +
//"(?=.*[0-9])" + //at least 1 digit
//"(?=.*[a-z])" + //at least 1 lower case letter
//"(?=.*[A-Z])" + //at least 1 upper case letter
"(?=.*[a-zA-Z])" + //any letter
"(?=.*[@#$%^&+=])" + //at least 1 special character
"(?=\\S+$)" + //no white spaces
".{4,}" + //at least 4 characters
"$");
private EditText inputEmail, inputPassword, confirmPassword,editDate; //hit option + enter if you on mac , for windows hit ctrl + enter
private Button btnSignIn, btnSignUp, btnResetPassword;
private ProgressBar progressBar;
private FirebaseAuth mAuth;
DatabaseReference reff;
Member member;
long maxid = 0;
String email, password, cPassword, id;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_sign_up);
//Get Firebase auth instance
mAuth = FirebaseAuth.getInstance();
reff = FirebaseDatabase.getInstance().getReference("Members");
btnSignIn = (Button) findViewById(R.id.sign_in_button);
btnSignUp = (Button) findViewById(R.id.sign_up_button);
inputEmail = (EditText) findViewById(R.id.email);
inputPassword = (EditText) findViewById(R.id.password);
confirmPassword = (EditText) findViewById(R.id.password2);
progressBar = (ProgressBar) findViewById(R.id.progressBar);
btnResetPassword = (Button) findViewById(R.id.btn_reset_password);
editDate = (EditText) findViewById(R.id.editDateBirth);
reff = FirebaseDatabase.getInstance().getReference().child("Member");
reff.addValueEventListener(
new ValueEventListener() {
@Override
public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
if (dataSnapshot.exists())
maxid = (dataSnapshot.getChildrenCount());
}
@Override
public void onCancelled(@NonNull DatabaseError databaseError) {
}
});
btnResetPassword.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
startActivity(new Intent(SignUpActivity.this, ResetPasswordActivity.class));
}
});
btnSignIn.setOnClickListener(
new View.OnClickListener() {
@Override
public void onClick(View v) {
finish();
startActivity(new Intent(SignUpActivity.this, LoginActivity.class));
}
});
btnSignUp.setOnClickListener(
new View.OnClickListener() {
@Override
public void onClick(View v) {
email = inputEmail.getText().toString();
password = inputPassword.getText().toString();
cPassword = confirmPassword.getText().toString();
if (TextUtils.isEmpty(email)) {
Toast.makeText(getApplicationContext(), "Enter email address!", Toast.LENGTH_SHORT).show();
return;
}
if (TextUtils.isEmpty(password)) {
Toast.makeText(getApplicationContext(), "Enter password!", Toast.LENGTH_SHORT).show();
return;
}
if (TextUtils.isEmpty(cPassword)) {
Toast.makeText(getApplicationContext(), "Confirm password!", Toast.LENGTH_SHORT).show();
return;
}
if (password.length() < 6) {
Toast.makeText(getApplicationContext(), "Password too short, enter minimum 6 characters!", Toast.LENGTH_SHORT).show();
return;
}
if (!(password.matches(cPassword))) {
Toast.makeText(getApplicationContext(), "Password and Confirmation Password are not the same!", Toast.LENGTH_SHORT).show();
return;
}
progressBar.setVisibility(View.VISIBLE);
//create user
mAuth.createUserWithEmailAndPassword(email, password)
.addOnCompleteListener(SignUpActivity.this,
new OnCompleteListener<AuthResult>() {
@Override
public void onComplete(@NonNull Task<AuthResult> task) {
Toast.makeText(SignUpActivity.this, "createUserWithEmail:onComplete:" + task.isSuccessful(), Toast.LENGTH_SHORT).show();
progressBar.setVisibility(View.GONE);
// If sign in fails, display a message to the user. If sign in succeeds
// the auth state listener will be notified and logic to handle the
// signed in user can be handled in the listener.
if (!task.isSuccessful()) {
Toast.makeText(SignUpActivity.this, "Authentication failed." + task.getException(),
Toast.LENGTH_SHORT).show();
} else {
mAuth.getCurrentUser().sendEmailVerification().addOnCompleteListener(
new OnCompleteListener<Void>() {
@Override
public void onComplete(@NonNull Task<Void> task) {
if (task.isSuccessful()) {
Toast.makeText(SignUpActivity.this, "Registered successfully. Please check your email for verification", Toast.LENGTH_SHORT).show();
inputEmail.setText("");
inputPassword.setText("");
Intent intent = new Intent(SignUpActivity.this, ProfileActivity.class);
intent.putExtra(EXTRA_EMAIL, email);
startActivity(intent);
finish();
}
}
});
}
}
});
}
});
}
@Override
protected void onResume() {
super.onResume();
progressBar.setVisibility(View.GONE);
}
private boolean validateEmail() {
String emailInput = inputEmail.getText().toString().trim();
if (emailInput.isEmpty()) {
inputEmail.setError("Field can't be empty");
return false;
} else if (!Patterns.EMAIL_ADDRESS.matcher(emailInput).matches()) {
inputEmail.setError("Please enter a valid email address");
return false;
} else {
inputEmail.setError(null);
return true;
}
}
private boolean validatePassword() {
String passwordInput = inputPassword.getText().toString().trim();
if (passwordInput.isEmpty()) {
inputPassword.setError("Field can't be empty");
return false;
} else if (!PASSWORD_PATTERN.matcher(passwordInput).matches()) {
inputPassword.setError("Password too weak");
return false;
} else {
inputPassword.setError(null);
return true;
}
}
public void addMember() {
//getting the values to save
email = inputEmail.getText().toString().trim();
id = reff.push().getKey();
//checking if the value is provided
if (!TextUtils.isEmpty(email)) {
//getting a unique id using push().getKey() method
//it will create a unique id and we will use it as the Primary Key for our Contact
//Saving the Contact
reff.child(id).setValue(member);
//setting edittext to blank again
inputEmail.setText("");
inputPassword.setText("");
//displaying a success toast
Toast.makeText(this, "Member added", Toast.LENGTH_LONG).show();
} else {
//if the value is not given displaying a toast
Toast.makeText(this, "Please enter a email", Toast.LENGTH_LONG).show();
}
}
private boolean updateMember(String id, String email) {
//getting the specified Contact reference
DatabaseReference dR = FirebaseDatabase.getInstance().getReference("Member").child(id);
//updating Contact
//Member member = new Member(id, email);
dR.setValue(member);
return true;
}
}
“活动B”
package com.example.munaseribrahimewallet;
import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import android.content.Intent;
import android.os.Bundle;
import android.text.TextUtils;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;
import com.google.firebase.database.DataSnapshot;
import com.google.firebase.database.DatabaseError;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
import com.google.firebase.database.ValueEventListener;
import org.w3c.dom.Text;
public class PaypalDB extends AppCompatActivity {
private Button btnPaypalLogin;
private EditText editPaypalLogin;
private TextView temail, thomeAddress, tcountry, tcompanyName, tcompanyAddress, tzipcode, tdate, tname, tpaypalEmail;
Member member;
DatabaseReference reff;
String memail, mhomeAddress, mcountry, mcompanyName, mcompanyAddress, mzipcode, mdate, mname, mpaypalEmail, mid;
long maxid = 0;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.paypal_db);
reff = FirebaseDatabase.getInstance().getReference("Members");
editPaypalLogin = (EditText) findViewById(R.id.editPaypalLogin);
btnPaypalLogin = (Button) findViewById(R.id.btnPaypalLogin);
temail= (TextView) findViewById(R.id.txtemail);
thomeAddress= (TextView) findViewById(R.id.txthomeaddress);
tcountry= (TextView) findViewById(R.id.txtcountry);
tcompanyName= (TextView) findViewById(R.id.txtcompanyname);
tzipcode= (TextView) findViewById(R.id.txtzipcode);
tdate= (TextView) findViewById(R.id.txtdate);
tname= (TextView) findViewById(R.id.txtname);
tcompanyAddress = (TextView) findViewById(R.id.txtcompany);
reff = FirebaseDatabase.getInstance().getReference().child("Member");
reff.addValueEventListener(
new ValueEventListener() {
@Override
public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
if (dataSnapshot.exists())
maxid = (dataSnapshot.getChildrenCount());
}
@Override
public void onCancelled(@NonNull DatabaseError databaseError) {
}
});
btnPaypalLogin.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Bundle extras = getIntent().getExtras();
memail = extras.getString("EXTRA_EMAIL");
mhomeAddress = extras.getString("EXTRA_HOMEADDRESS");
mcountry = extras.getString("EXTRA_SPINNERCOUNTRYTEXT");
mcompanyName = extras.getString("EXTRA_COMPANYNAME");
mcompanyAddress = extras.getString("EXTRA_COMPANYADDRESS");
mzipcode = extras.getString("EXTRA_ZIPCODE");
mdate = extras.getString("EXTRA_DATE");
mname = extras.getString("EXTRA_NAME");
mpaypalEmail = editPaypalLogin.getText().toString();
tcompanyAddress.setText(mcompanyAddress);
tname.setText(mname);
mid = reff.push().getKey();
DatabaseReference dR = FirebaseDatabase.getInstance().getReference("Member").child(mid);
reff.child(mid).setValue(member);
member = new Member(mid, memail, mdate, mhomeAddress, mcountry, mcompanyName, mcompanyAddress, mzipcode, mpaypalEmail, mname);
dR.setValue(member);
}
});
}
}
最佳答案
尝试使用sharedPreference
创建SharedPreferences
SharedPreferences pref = getApplicationContext().getSharedPreferences("MyPref", MODE_PRIVATE);
Editor editor = pref.edit();
将数据存储为KEY / VALUE对
editor.putBoolean("key_name1", true); // Saving boolean - true/false
editor.putInt("key_name2", "int value"); // Saving integer
editor.putFloat("key_name3", "float value"); // Saving float
editor.putLong("key_name4", "long value"); // Saving long
editor.putString("key_name5", "string value"); // Saving string
// Save the changes in SharedPreferences
editor.commit(); // commit changes
获取SharedPreferences数据
// If value for key not exist then return second param value - In this case null
boolean userFirstLogin= pref.getBoolean("key_name1", true); // getting boolean
int pageNumber=pref.getInt("key_name2", 0); // getting Integer
float amount=pref.getFloat("key_name3", null); // getting Float
long distance=pref.getLong("key_name4", null); // getting Long
String email=pref.getString("key_name5", null); // getting String
Deleting Key value from SharedPreferences
editor.remove("key_name3"); // will delete key key_name3
editor.remove("key_name4"); // will delete key key_name4
// Save the changes in SharedPreferences
editor.commit(); // commit changes
从SharedPreferences清除所有数据
editor.clear();
editor.commit(); // commit changes
如果您难以理解我的解决方案，请参考This to get more details
关于java - Android Studio将变量发送到其他 Activity 并同时打开 Activity ，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/57127284/