一、使用Intent & Bundle传递数据。
（1）传递简单数据
//传递数据
Bundle bundle = new Bundle();
Intent intent = new Intent(MainActivity.this, TransmitActivity.class);
bundle.putString("name", "张三");
bundle.putString("age", "23");
intent.putExtra("person", bundle);
startActivity(intent);
//接收数据
Intent intent = getIntent();
Bundle bundle = intent.getBundleExtra("person");
String name = bundle.getString("name");
String age = bundle.getString("age");
tv_name.setText("姓名:" + name + "\n" + "年龄:" + age);
（2）传递复杂数据
把数据转成Serializable对象
public class Person implements Serializable {
private String name;
private String age;
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;
}
}
//传递数据
Person person = new Person();
person.setName("李四");
person.setAge("24");
Bundle bundle = new Bundle();
Intent intent = new Intent(MainActivity.this, TransmitActivity.class);
bundle.putSerializable("person", person);
intent.putExtras(bundle);
startActivity(intent);
//接收数据
Intent intent = getIntent();
Bundle bundle = intent.getExtras();
Person person = (Person) bundle.getSerializable("person");
tv_name.setText("姓名:" + person.getName() + "\n" + "年龄:" + person.getAge());
（3）传递回传数据
//传递数据
Person person = new Person();
person.setName("李四");
person.setAge("24");
Bundle bundle = new Bundle();
Intent intent = new Intent(MainActivity.this, TransmitActivity.class);
bundle.putSerializable("person", person);
intent.putExtras(bundle);
startActivityForResult(intent, 200);
//重写onActivityResult方法，用来接收TransmitActivity回传的数据。
@Override
protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (resultCode == 30) {
String name = data.getStringExtra("name");
String age = data.getStringExtra("age");
tv_name.setText("姓名:" + name + "\n" + "年龄:" + age);
}
}
//onKeyDown方法，监听返回按钮。回传数据
@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
if (keyCode == KeyEvent.KEYCODE_BACK) {
Intent intent = new Intent();
intent.putExtra("name", "王五");
intent.putExtra("age", "25");
setResult(30, intent);
finish();
}
return true;
}
二、通过存储介质来分享数据：SharedPreferences
创建工具类
public class SharedPreferencesUtils {
public static final String name = "test";
private static SharedPreferencesUtils instance;
public static SharedPreferencesUtils getInstance() {
if (instance == null) {
synchronized (SharedPreferencesUtils.class) {
if (instance == null) {
instance = new SharedPreferencesUtils();
}
}
}
return instance;
}
/**
* 保存数据，修改数据
*
* @param key
* @param value
* @param <V>
*/
public <V> void setValue(@NonNull String key, V value) {
SharedPreferences sp = MyApp.getInstance().getSharedPreferences(name, Context.MODE_PRIVATE);
SharedPreferences.Editor editor = sp.edit();
if (value instanceof String) {
editor.putString(key, (String) value);
} else if (value instanceof Integer) {
editor.putInt(key, (Integer) value);
} else if (value instanceof Long) {
editor.putLong(key, (Long) value);
} else if (value instanceof Boolean) {
editor.putBoolean(key, (Boolean) value);
} else if (value instanceof Float) {
editor.putFloat(key, (Float) value);
}
editor.commit();
}
/**
* 读取数据
*
* @param key
* @param defaultValue
* @param <V>
* @return
*/
public <V> V getValue(@NonNull String key, V defaultValue) {
SharedPreferences sp = MyApp.getInstance().getSharedPreferences(name, Context.MODE_PRIVATE);
Object value = defaultValue;
if (defaultValue instanceof String) {
value = sp.getString(key, (String) defaultValue);
} else if (defaultValue instanceof Integer) {
value = sp.getInt(key, (Integer) defaultValue);
} else if (defaultValue instanceof Long) {
value = sp.getLong(key, (Long) defaultValue);
} else if (defaultValue instanceof Boolean) {
value = sp.getBoolean(key, (Boolean) defaultValue);
} else if (defaultValue instanceof Float) {
value = sp.getFloat(key, (Float) defaultValue);
}
return (V) value;
}
/**
* 清空数据
*/
public void clearData() {
SharedPreferences.Editor editor = MyApp.getInstance().
getSharedPreferences(name, Context.MODE_PRIVATE).edit();
editor.clear();
editor.commit();
}
}
//存储数据
SharedPreferencesUtils sharedPreferencesUtils = SharedPreferencesUtils.getInstance();
sharedPreferencesUtils.setValue("name", "赵六");
sharedPreferencesUtils.setValue("age", "26");
//获取数据
SharedPreferencesUtils sharedPreferencesUtils = SharedPreferencesUtils.getInstance(getApplicationContext());
String name = sharedPreferencesUtils.getValue("name", "null");
String age = sharedPreferencesUtils.getValue("age", "null");
三、通过接口的调用来传递数据
创建接口
public interface Transmit {
void send(String name, String age);
}
调用接口
public class Person {
public Transmit transmit;
public Person(Transmit transmit) {
this.transmit = transmit;
}
public void send() {
transmit.send("田七", "27");
}
}
实现接口
public class MainActivity extends AppCompatActivity implements Transmit {
private TextView tv_name;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
tv_name = findViewById(R.id.tv_name);
Person person = new Person(this);
person.send();
}
@Override
public void send(String name, String age) {
tv_name.setText("姓名:" + name + "\n" + "年龄:" + age);
}
}
四、通过广播的方式传递数据
//创建接收广播
public class MyBroadcastReceiver extends BroadcastReceiver {
@Override
public void onReceive(Context context, Intent intent) {
String name = intent.getStringExtra("name");
String age = intent.getStringExtra("age");
tv_name.setText("姓名:" + name + "\n" + "年龄:" + age);
}
}
//注册广播
IntentFilter intentFilter = new IntentFilter();
intentFilter.addAction("android.intent.action.MY_BROADCAST_RECEIVER");
registerReceiver(new MyBroadcastReceiver(), intentFilter);
//发送广播
Intent intent = new Intent("android.intent.action.MY_BROADCAST_RECEIVER");
intent.putExtra("name","小明");
intent.putExtra("age","28");
sendBroadcast(intent);
