常见的Android数据传递方法汇总

一、Intent与Bundle

1、Activty与Activity

1.1、传递简单数据

（1）传单个值（以String类型为例）

发送数据

 Intent intent = new Intent(A.this, B.class);intent.putExtra("key", value);startActivity(intent);

接收数据

 // 获取数据的方法需要根据传递的数据类型而定Intent reIntent = getIntent();String tempStr = reIntent.getStringExtra("key");

（2）传多个值

发送数据

 Intent intent = new Intent(A.this, B.class);Bundle bd = new Bundle();bd.putString("name", "张三");bd.putInt("age", 23);intent.putExtras(bd);startActivity(intent);

接收数据

 Intent reIntent = getIntent();Bundle reBd = reIntent.getExtras();String name = reBd.getString("name");int age = reBd.getInt("age");

1.2、传递复杂数据

数组

（1）纯Intent

传递数据

 Intent intent = new Intent(A.this, B.class);intent.putExtra("arrName", new String[]{"张三", "李四", "王五"});startActivity(intent);

接收数据

 Intent reIntent = getIntent();reIntent.getStringArrayExtra("arrName");

（2）Intent和Bundle

传递数据

 Intent intent = new Intent(A.this, B.class);Bundle bd = new Bundle();bd.putStringArray("arrName", new String[]{"张三", "李四", "王五"});intent.putExtras(bd);startActivity(intent);

接收数据

 Intent reIntent = getIntent();Bundle reBd = reIntent.getExtras();reBd.getStringArray("arrName");

集合

（1）List<基本数据类型或String、Integer>

单用Intent或Intent与Bundle结合都可以

发送数据

 ArrayList<String> strList = new ArrayList<>();stringList.add("张三");stringList.add("李四");Intent listIntent = new Intent(A.this, B.claaa);listIntent.putStringArrayListExtra("strList", strList);startActivity(listIntent);

接收数据

 Intent reIntent = getIntent();reIntent.getStringArrayListExtra("strList");

（2）List<自定义对象>

首先自定义对象要实现Serializable接口

import java.io.Serializable;public class Student implements Serializable {private String name;private int age;private String sex;private String grade;private String school;public Student(String name, int age, String sex, String grade, String school) {this.name = name;this.age = age;this.sex = sex;this.grade = grade;this.school = school;}public String getName() {return name;}public void setName(String name) {this.name = name;}public int getAge() {return age;}public void setAge(int age) {this.age = age;}public String getSex() {return sex;}public void setSex(String sex) {this.sex = sex;}public String getGrade() {return grade;}public void setGrade(String grade) {this.grade = grade;}public String getSchool() {return school;}public void setSchool(String school) {this.school = school;}
}

发送数据

 Intent intent = new Intent(A.this, B.class);List<Student> studentList = new ArrayList<>();studentList.add(new Student("张三", 25, "男", "大三", "广州大学"));studentList.add(new Student("李四", 24, "男", "大二", "贵州大学"));studentList.add(new Student("李红", 27, "男", "大四", "清华大学"));studentList.add(new Student("王五", 23, "男", "大一", "北京大学"));intent.putExtra("studentList", (Serializable) studentList);startActivity(intent);

接收数据

 Intent reIntent = getIntent();List<Student> reStudentList = (List<Student>) reIntent.getSerializableExtra("studentList");

对象

（1）使用Serializable序列化对象；

序列化对象

import java.io.Serializable;/*** 学生*/
public class Student implements Serializable {private String name;private int age;private String sex;private String grade;private String school;public Student(String name, int age, String sex, String grade, String school) {this.name = name;this.age = age;this.sex = sex;this.grade = grade;this.school = school;}public String getName() {return name;}public void setName(String name) {this.name = name;}public int getAge() {return age;}public void setAge(int age) {this.age = age;}public String getSex() {return sex;}public void setSex(String sex) {this.sex = sex;}public String getGrade() {return grade;}public void setGrade(String grade) {this.grade = grade;}public String getSchool() {return school;}public void setSchool(String school) {this.school = school;}
}

发送数据

 Intent intent = new Intent(A.this, B.class);Student stu1 = new Student("张三", 25, "男", "大三", "广州大学");intent.putExtra("stu1", stu1);startActivity(intent);

接收数据

 Intent reIntent = getIntent();Student stu1 = (Student) reIntent.getSerializableExtra("stu1");

（2）使用Parcelable序列化对象；

序列化对象

import android.os.Parcel;
import android.os.Parcelable;/*** 课程*/
public class Course implements Parcelable {private String courseName;private String courseType;public Course() {}public Course(String courseName, String courseType) {this.courseName = courseName;this.courseType = courseType;}public String getCourseName() {return courseName;}public void setCourseName(String courseName) {this.courseName = courseName;}public String getCourseType() {return courseType;}public void setCourseType(String courseType) {this.courseType = courseType;}@Overridepublic int describeContents() {// 内容描述，返回0就可以return 0;}@Overridepublic void writeToParcel(Parcel dest, int flags) {// 将Course对象转化成Parcel，// dest是目标Parcel，// flags标志object是如何被写的。// 0或者PARCELABLE_WRITE_RETURN_VALUEdest.writeString(courseName);dest.writeString(courseType);}public static final Creator<Course> CREATOR = new Creator<Course>() {@Overridepublic Course createFromParcel(Parcel in) {// 将Parcel映射成Course对象Course mCourse = new Course();// 同种数据类型，顺序为先进先出mCourse.courseName = in.readString();mCourse.courseType = in.readString();return mCourse;}@Overridepublic Course[] newArray(int size) {return new Course[size];}};
}

发送数据

 Intent intent = new Intent(A.this, B.class);Course course = new Course("语文", "文科");intent.putExtra("course", course);startActivity(intent);

接收数据

 Intent reIntent = getIntent();Course mCourse = reIntent.getParcelableExtra("course");

（3）使用Gson将对象转化为Json格式再传递。

导入依赖包

 //添加Gson依赖implementation 'com.google.code.gson:gson:2.8.8'

定义对象

public class Book {private String bookName;private String bookAuthor;public Book(String bookName, String bookAuthor) {this.bookName = bookName;this.bookAuthor = bookAuthor;}public String getBookName() {return bookName;}public void setBookName(String bookName) {this.bookName = bookName;}public String getBookAuthor() {return bookAuthor;}public void setBookAuthor(String bookAuthor) {this.bookAuthor = bookAuthor;}
}

发送数据

 Intent intent = new Intent(A.this, B.class);Book book = new Book("西游记", "吴承恩");intent.putExtra("book", new Gson().toJson(book));startActivity(intent);

接收数据

 Intent reIntent = getIntent();String bookJson = reIntent.getStringExtra("book");Book mBook = new Gson().fromJson(bookJson, Book.class);

2、Activity与Fragment

2.1、Activity传递数据给Fragment

1、通过构造函数传递

step1：在RightFragment.java中重载构造函数

 private String mData;public RightFragment(String data) {mData = data;}

step2：在MainActivityFour.java中创建Fragment实例的同时，通过构造函数将数据传递过去

    RightFragment rightFragment = new RightFragment("GetDataFromMainTwo");FragmentManager fragmentManager = getSupportFragmentManager();FragmentTransaction transaction = fragmentManager.beginTransaction();transaction.replace(R.id.fl_right, rightFragment, "rightFragment");transaction.commit();

2、通过setArguments()传递

step1：在MainActivityFour.java初始化Fragment时，使用setArgments传递数据

 RightFragment rightFragment = new RightFragment();Bundle bundle = new Bundle();bundle.putString("main_data", "GetDataFromMainThree");rightFragment.setArguments(bundle);FragmentManager fragmentManager = getSupportFragmentManager();FragmentTransaction transaction = fragmentManager.beginTransaction();transaction.replace(R.id.fl_right, rightFragment, "rightFragment");transaction.commit();

step2：在RightFragment.java中获取数据

 @Overridepublic void onActivityCreated(Bundle savedInstanceState) {super.onActivityCreated(savedInstanceState);if (isAdded()) {String getData = "";Bundle bundle = getArguments();if (bundle != null)getData = getArguments().getString("main_data");tvShowContent.setText(getData);}}

3、Fragment中定义方法再调用

step1：在RightFragment.java中定义一个接收数据的方法

 public void setData(String dataMsg) {tvShowContent.setText(dataMsg);}

step2：在MianActivityFour.java中发送数据

 rightFragment.setData("GetDataFromMain");

2.2、Fragment传递数据给Activity

通过接口回调获取数据

step1：在RightFragment.java中定义一个接口以及设置接口的方法

 public onDataTransmissionListener mListener;public interface onDataTransmissionListener {public void dataTransmission(String data);}public void setOnDataTransmissionListener(onDataTransmissionListener mListener) {this.mListener = mListener;}

step2：在RightFragment.java中通过接口传递数据

 if (mListener != null) {mListener.dataTransmission(btnTextTwo.getText().toString());}

step3：在MianActivityFour.java中设置Fragment并监听RightFragment.java的接口

    RightFragment rightFragment = new RightFragment();FragmentManager fragmentManager = getSupportFragmentManager();FragmentTransaction transaction = fragmentManager.beginTransaction();transaction.replace(R.id.fl_right, rightFragment, "rightFragment");transaction.commit();rightFragment.setOnDataTransmissionListener(new RightFragment.onDataTransmissionListener() {@Overridepublic void dataTransmission(String data) {String fgData = data; //获取Fragment传过来的内容}});

3、Fragment与Fragment

先创建一个简单的布局

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"xmlns:app="http://schemas.android.com/apk/res-auto"xmlns:tools="http://schemas.android.com/tools"android:layout_width="match_parent"android:layout_height="match_parent"tools:context=".MainActivityFour"android:orientation="horizontal"><FrameLayoutandroid:id="@+id/fl_left"android:layout_width="0dp"android:layout_weight="1"android:layout_height="match_parent"/><FrameLayoutandroid:id="@+id/fl_right"android:layout_width="0dp"android:layout_weight="2"android:layout_height="match_parent"/></LinearLayout>

3.1、获取Fragment的id或Tag

核心代码如下，

step1：在MainActivityFour.java中设置Fragment

 LeftFragment leftFragment = new LeftFragment();RightFragment rightFragment = new RightFragment();FragmentManager fragmentManager = getSupportFragmentManager();FragmentTransaction transaction = fragmentManager.beginTransaction();transaction.replace(R.id.fl_left, leftFragment, "leftFragment");transaction.replace(R.id.fl_right, rightFragment, "rightFragment");transaction.commit();

step2：在RightFragment.java中定义一个接收数据的方法

 public void setData(String dataMsg) {tvShowContent.setText(dataMsg);}

step3：在LeftFragment.java中根据FragmentID或FragmentTag获取RightFragment对象

 RightFragment rightFragment = (RightFragment) getActivity().getSupportFragmentManager().findFragmentById(R.id.fl_right);rightFragment.setData(btnTextOne.getText().toString());

或

 RightFragment rightFragment = (RightFragment) getActivity().getSupportFragmentManager().findFragmentByTag("rightFragment");rightFragment.setData(btnTextOne.getText().toString());

3.2、接口回调

step1：在LeftFragment.java中定义一个接口以及设置接口的方法

 public onDataTransmissionListener mListener;public interface onDataTransmissionListener {public void dataTransmission(String data);}public void setOnDataTransmissionListener(onDataTransmissionListener mListener) {this.mListener = mListener;}

step2：在LeftFragment.java中通过接口传递数据

 if (mListener != null) {mListener.dataTransmission(btnTextTwo.getText().toString());}

step3：在RightFragment.java中定义一个接收数据的方法

 public void setData(String dataMsg) {tvShowContent.setText(dataMsg);}

step4：在MianActivityFour.java中设置Fragment并监听LeftFragment.java的接口

 LeftFragment leftFragment = new LeftFragment();RightFragment rightFragment = new RightFragment();FragmentManager fragmentManager = getSupportFragmentManager();FragmentTransaction transaction = fragmentManager.beginTransaction();transaction.replace(R.id.fl_left, leftFragment, "leftFragment");transaction.replace(R.id.fl_right, rightFragment, "rightFragment");transaction.commit();leftFragment.setOnDataTransmissionListener(new LeftFragment.onDataTransmissionListener() {@Overridepublic void dataTransmission(String data) {rightFragment.setData(data);}});

二、EventBus

上述Activity与Activity、Activity与Fragment以及Frament与Fragment之间的通信，都可以使用EventBus实现，具体步骤如下：

1、在app目录下的build.gradle文件中添加eventbus依赖；

implementation 'org.greenrobot:eventbus:3.0.0'

2、创建EventBus信息传递类；

public class EventInit {private String name;private String age;private String sex;private String grade;private String school;public EventInit(String name, String age, String sex, String grade, String school) {this.name = name;this.age = age;this.sex = sex;this.grade = grade;this.school = school;}public String getAllValue() {return "name: " + name+ "\nage: " + age+ "\nsex: " + sex+ "\ngrade: " + grade+ "\nschool: " + school;}public String getName() {return name;}public void setName(String name) {this.name = name;}public String getAge() {return age;}public void setAge(String age) {this.age = age;}public String getSex() {return sex;}public void setSex(String sex) {this.sex = sex;}public String getGrade() {return grade;}public void setGrade(String grade) {this.grade = grade;}public String getSchool() {return school;}public void setSchool(String school) {this.school = school;}
}

3、在发送消息的Activty或Fragment中使用下面代码；

 EventBus.getDefault().post(new EventInit(name, age, sex, grade, school));

4、在接收数据的Activity或Fragment中注册和注销EventBus，并接收消息；

一般建议：

（1）在onStart()中注册EventBus.

 @Overrideprotected void onStart() {super.onStart();//注册EventBus 接收数据if (!EventBus.getDefault().isRegistered(this)) {EventBus.getDefault().register(this);}}

（2）在onDestroy()中注销EventBus.

 @Overrideprotected void onDestroy() {super.onDestroy();//注销事件接收EventBus.getDefault().unregister(this);}

（3）定义接收消息的方法

 // 接收消息（post）@Subscribe(threadMode = ThreadMode.MAIN)public void onEventInit(EventInit eventInit) {try {String allValue = eventInit.getAllValue();//更改TextView内容tvReceiveText.setText(allValue);} catch (Exception e) {e.printStackTrace();}}

5、运行程序后，可能会出现如下问题；

（1）在Run窗口可以看到下面的提示，但并不会报错；

 EventBus ： No subscribers registered for event class

（2）以上问题是由于EventBus不适合向一个不存在于activity栈中的activity发送消息，这样是失败的，fragment同理。

例如：

情况1：一个activity 还没有生成，就post，肯定报这样的错；

情况2：一个activity曾经生成了，但是不在activity栈中了，也是收不到消息的

情况3：生命周期的问题。如果是在onStop()方法中注销了EventBus，而在特殊情况下恰好调用了接收消息的Activty或Fragment中的onStop()方法，这也就出现了上述的问题。

6、解决方法；

（1）依旧使用上述的post方式发送消息，不过需要加上延时操作，如下：

 //延时发送数据new Thread(new Runnable() {@Overridepublic void run() {try {Thread.sleep(500);} catch (InterruptedException e) {e.printStackTrace();}EventBus.getDefault().post(new EventInit(name, age, sex, grade, school));}}).start();

（2）或者使用postSticky方式替换post方式发送消息，如下：

 //使用粘性事件EventBus.getDefault().postSticky(new EventInit(name, age, sex, grade, school));

在接收消息的Activity或Fragment中定义接收消息的方法：

// 接收消息（postStick）
@Subscribe(threadMode = ThreadMode.MAIN, sticky = true)public void onEventInitTwo(EventInit eventInit) {try {String allValue = eventInit.getAllValue();//更改TextView内容tvReceiveText.setText(allValue);} catch (Exception e) {e.printStackTrace();}}

（3）post与postSticky相比，若post事件没有被订阅，则该事件会被流传，即作废；而postSicky是将完整的事件放到内存中，待EventBus注册时再从内存中获取该事件，然后包装成一个新的post事件进行发布，由于此时EventBus注册已执行完毕，所以postSticky事件可以正常使用。