Question

我想从两个活动（StudyProgram.java和LogIn.java）中设置对象（User.java）中的数据，并在运行时将其显示在单个活动（SecondActivity.java）或屏幕中，但我面对的是问题。我的代码在单个活动中显示共享数据，但不在同一时间或屏幕上显示。它分别在两个屏幕上显示。但是，我想在同一个屏幕上显示它，这对我来说很难。我的代码是

Login.java

Intent intent = new Intent(Login.this,SecondActivity.class);
user.setName(name);
user.setFacebookId(id);
intent.putExtra("User", user);
startActivity(intent);

StudyProgram.java

Intent intent = new Intent(getContext(),SecondActivity.class);
user.setVuId(data);
user.setStudyProgram(data1);
intent.putExtra("User", user);
startActivity(intent);

User.java

package com.technerdshub.vusocial.Models;

import android.os.Parcel;
import android.os.Parcelable;

import java.io.Serializable;

/**
 * Created by MFRajput on 01/05/16.
 */
public class User implements Serializable {

    private String studyProgram;
    private String name;
    private String facebookId;
    private String vuId;

    public User(String studyProgram, String name, String facebookId, String vuId) {
        this.studyProgram = studyProgram;
        this.name = name;
        this.facebookId = facebookId;
        this.vuId = vuId;
    }

    public User() {
       }


    public String getVuId(String data) {
        return vuId;
    }

    public void setVuId(String vuId) {
        this.vuId = vuId;
    }

    public String getStudyProgram(String data1) {
        return studyProgram;
    }

    public void setStudyProgram(String studyProgram) {
        this.studyProgram = studyProgram;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getFacebookId() {
        return facebookId;
    }

    public void setFacebookId(String facebookId) {
        this.facebookId = facebookId;
    }

    @Override
    public String toString() {
        return "User{" +
                "studyProgram='" + studyProgram + '\'' +
                ", name='" + name + '\'' +
                ", facebookId='" + facebookId + '\'' +
                ", vuId='" + vuId + '\'' +
                '}';
    }

    }

SecondActivity.java

package com.technerdshub.vusocial.Activities;

import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.TextView;

import com.technerdshub.vusocial.Models.User;
import com.technerdshub.vusocial.R;

public class SecondActivity extends AppCompatActivity {

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

        Intent intent = this.getIntent();
        User user = (User) intent.getSerializableExtra("User");

        TextView textView = (TextView) findViewById(R.id.textView2);
        textView.setText(user.toString());
    }
}

请有人帮助我，我该怎么办？

Answer 1

如何使用单身人士？

public class User implements Serializable {

    private static User instance;

    private String studyProgram;
    private String name;
    private String facebookId;
    private String vuId;

    private User() {}

    public static User getInstance(){
        if (instance == null){
            instance = new User();
        }
        return instance;
    }
    ...
}

这是一个单例，没有必要将它传递给intent，因为它可以全局访问。

在Login.java中执行

Intent intent = new Intent(Login.this,SecondActivity.class);
User user = User.getInstance();
user.setName(name);
user.setFacebookId(id);
startActivity(intent);

在StudyPRogram.java中

Intent intent = new Intent(getContext(),SecondActivity.class);
User user = User.getInstance();
user.setVuId(data);
user.setStudyProgram(data1);
startActivity(intent);

在SecondActivity中执行：

public class SecondActivity extends AppCompatActivity {

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

    User user = User.getInstance();

    TextView textView = (TextView) findViewById(R.id.textView2);
    textView.setText(user.toString());
}

Answer 2

将所有用户变量和方法设为静态，然后通过User类访问它们，而不是创建用户类的实例。

 User.setVuId(data);

而不是像

那样实例化它

User user = new User();
user.setVuId(data);

从多个活动中设置模型中的数据

2 个答案: