使用回调在活动之间进行新的实时交互：

-步骤01：实现共享接口

public interface SharedCallback {
    public String getSharedText(/*you can define arguments here*/);
}

-步骤02：实现共享类

final class SharedMethode {
    private static WeakReference<Context> mContext;

    private static SharedMethode sharedMethode = new SharedMethode();

    private SharedMethode() {
        super();
    }

    public static SharedMethode getInstance() {
        return sharedMethode;
    }

    public void setContext(Context context) {
        if (mContext != null)
            return;

        mContext = new WeakReference<Context>(context);
    }

    public boolean contextAssigned() {
        return mContext != null && mContext.get() != null;
    }

    public Context getContext() {
        return mContext.get();
    }

    public void freeContext() {
        if (mContext != null) mContext.clear();
        mContext = null;
    }
}

-步骤03：：在第一个活动中玩代码

public class FirstActivity extends Activity implements SharedCallback {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.your_layout);

        // call playMe from here or there
        playMe();
    }

    private void playMe() {
        SharedMethode.getInstance().setContext(this);
        Intent intent = new Intent(this, SecondActivity.class);
        startActivity(intent);
    }

    @Override
    public String getSharedText(/*passed arguments*/) {
        return "your result";
    }

}

-步骤04：：在SecondActivity中完成游戏

public class SecondActivity extends Activity {

    private SharedCallback sharedCallback;

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

        if (SharedMethode.getInstance().contextAssigned()) {
            if (SharedMethode.getInstance().getContext() instanceof SharedCallback)
                sharedCallback = (SharedCallback) SharedMethode.getInstance().getContext();

            // to prevent memory leak
            SharedMethode.freeContext();
        }

        // You can now call your implemented methodes from anywhere at any time
        if (sharedCallback != null)
            Log.d("TAG", "Callback result = " + sharedCallback.getSharedText());

    }

    @Override
    protected void onDestroy() {
        sharedCallback = null;
        super.onDestroy();
    }

}

步骤05：：您还可以实现backword回调（从First到Second），以从SecondAvctivity获取一些结果或调用一些方法

Intent intent = new Intent(YourCurrentActivity.this, YourActivityName.class);
intent.putExtra("NAme","John");
intent.putExtra("Id",1);
startActivity(intent);

您可以在其他活动中检索它。两种方式：

int id = getIntent.getIntExtra("id", /* defaltvalue */ 2);

第二种方法是：

Intent i = getIntent();
String name = i.getStringExtra("name");

/*
 * If you are from transferring data from one class that doesn't
 * extend Activity, then you need to do something like this.
 */ 

public class abc {
    Context context;

    public abc(Context context) {
        this.context = context;
    }

    public void something() {
        context.startactivity(new Intent(context, anyone.class).putextra("key", value));
    }
}

标准方法。

Intent i = new Intent(this, ActivityTwo.class);
AutoCompleteTextView textView = (AutoCompleteTextView) findViewById(R.id.autocomplete);
String getrec=textView.getText().toString();
Bundle bundle = new Bundle();
bundle.putString(“stuff”, getrec);
i.putExtras(bundle);
startActivity(i);

现在，在第二个活动中，从捆绑包中检索数据：

获取捆绑包

Bundle bundle = getIntent().getExtras();

提取数据…

String stuff = bundle.getString(“stuff”); 

查理·柯林斯用Application.class给了我一个完美的答案。我不知道我们可以这么容易地将其子类化。这里是一个使用自定义应用程序类的简化示例。

AndroidManifest.xml

赋予android:name属性以使用您自己的应用程序类。

...
<application android:name="MyApplication"
    android:allowBackup="true"
    android:icon="@drawable/ic_launcher"
    android:label="@string/app_name"
    android:theme="@style/AppTheme" >
....

我的应用程序.java

将其用作全局引用持有者。它在同一个过程中运行良好。

public class MyApplication extends Application {
    private MainActivity mainActivity;

    @Override
    public void onCreate() {
        super.onCreate();
    }

    public void setMainActivity(MainActivity activity) { this.mainActivity=activity; }
    public MainActivity getMainActivity() { return mainActivity; }
}

主要活动.java

设置应用程序实例的全局“singleton”引用。

public class MainActivity extends Activity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        ((MyApplication)getApplication()).setMainActivity(this);
    }
    ...

}

我的首选项.java

一个简单的例子，我使用另一个活动实例的主活动。

public class MyPreferences extends PreferenceActivity
            implements SharedPreferences.OnSharedPreferenceChangeListener {
    @SuppressWarnings("deprecation")
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        addPreferencesFromResource(R.xml.preferences);
        PreferenceManager.getDefaultSharedPreferences(this)
            .registerOnSharedPreferenceChangeListener(this);
    }

    @Override
    public void onSharedPreferenceChanged(SharedPreferences prefs, String key) {
        if (!key.equals("autostart")) {
            ((MyApplication)getApplication()).getMainActivity().refreshUI();
        }
    }
}

源类：

Intent myIntent = new Intent(this, NewActivity.class);
myIntent.putExtra("firstName", "Your First Name Here");
myIntent.putExtra("lastName", "Your Last Name Here");
startActivity(myIntent)

目标类（NewActivity类）：

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.view);

    Intent intent = getIntent();

    String fName = intent.getStringExtra("firstName");
    String lName = intent.getStringExtra("lastName");
}