/**

     * Find the view in the hierarchy rooted at this view that currently has

     * focus.

     *

     * @return The view that currently has focus, or null if no focused view can

     *         be found.

     */

    public View findFocus() {

        return (mPrivateFlags & PFLAG_FOCUSED) != 0 ? this : null;

    }

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

    xmlns:tools="http://schemas.android.com/tools"

    android:layout_width="match_parent"

    android:layout_height="match_parent"

    android:orientation="vertical"

    android:padding="20dp"

    tools:context="com.example.testcode.MainActivity" >

    <TextView

        android:id="@+id/tv"

        android:layout_width="match_parent"

        android:layout_height="200dp"

        android:layout_marginBottom="10dp"

        android:clickable="true"

        android:focusable="true"

        android:textSize="30sp"

        android:focusableInTouchMode="true"

        android:background="@drawable/select"

        android:textColor="#ffffff" />

    <LinearLayout

        android:id="@+id/aaa"

        android:layout_width="match_parent"

        android:layout_height="0dp"

        android:layout_marginBottom="10dp"

        android:layout_weight="1"

        android:orientation="horizontal" >

        <Button

            android:id="@+id/bt_1"

            android:layout_width="60dp"

            android:layout_height="60dp"

            android:layout_marginLeft="5dp"

            android:background="@drawable/select"

            android:focusableInTouchMode="true"

            android:textColor="#ffffff" />

        <Button

            android:id="@+id/bt_2"

            android:layout_width="60dp"

            android:layout_height="60dp"

            android:layout_marginLeft="5dp"

            android:background="@drawable/select"

            android:focusableInTouchMode="true"

            android:textColor="#ffffff" />

        <Button

            android:id="@+id/bt_3"

            android:layout_width="60dp"

            android:layout_height="60dp"

            android:layout_marginLeft="5dp"

            android:background="@drawable/select"

            android:focusableInTouchMode="true"

            android:textColor="#ffffff" />

        <Button

            android:id="@+id/bt_4"

            android:layout_width="60dp"

            android:layout_height="60dp"

            android:layout_marginLeft="5dp"

            android:background="@drawable/select"

            android:focusableInTouchMode="true"

            android:textColor="#ffffff" />

    </LinearLayout>

    <Button

        android:id="@+id/bt"

        android:layout_width="100dp"

        android:layout_height="100dp"

        android:background="@drawable/select" />

</LinearLayout>

package com.example.testcode;

import com.example.testcode.R.id;

import android.app.Activity;

import android.content.Intent;

import android.os.Bundle;

import android.view.Menu;

import android.view.MenuItem;

import android.view.View;

import android.view.View.OnClickListener;

import android.widget.Button;

import android.widget.LinearLayout;

import android.widget.TextView;

public class MainActivity extends Activity {

    private TextView textView;

    private Button button;

    private LinearLayout relativeLayout;

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

        textView = (TextView) findViewById(R.id.tv);

        button = (Button)findViewById(R.id.bt);

        relativeLayout = (LinearLayout)findViewById(R.id.aaa);

        textView.setText("当前焦点所在view");

        button.setText("显示当前focus");

        button.setOnClickListener(new OnClickListener() {

            @Override

            public void onClick(View arg0) {

                // TODO Auto-generated method stub

                View view = relativeLayout.findFocus();

                textView.setText(""+view);

            }

        });

    }

    @Override

    public boolean onCreateOptionsMenu(Menu menu) {

        // Inflate the menu; this adds items to the action bar if it is present.

        getMenuInflater().inflate(R.menu.main, menu);

        return true;

    }

    @Override

    public boolean onOptionsItemSelected(MenuItem item) {

        // Handle action bar item clicks here. The action bar will

        // automatically handle clicks on the Home/Up button, so long

        // as you specify a parent activity in AndroidManifest.xml.

        int id = item.getItemId();

        if (id == R.id.action_settings) {

            return true;

        }

        return super.onOptionsItemSelected(item);

    }

}

  /**

     * Find the nearest view in the specified direction that can take focus.

     * This does not actually give focus to that view.

     *

     * @param direction One of FOCUS_UP, FOCUS_DOWN, FOCUS_LEFT, and FOCUS_RIGHT

     *

     * @return The nearest focusable in the specified direction, or null if none

     *         can be found.

     */

    public View focusSearch(@FocusRealDirection int direction) {

        if (mParent != null) {

            return mParent.focusSearch(this, direction);

        } else {

            return null;

        }

    }

<Button

            android:id="@+id/bt_3"

            android:layout_width="60dp"

            android:layout_height="60dp"

            android:layout_marginLeft="5dp"

            android:background="@drawable/select"

            android:focusableInTouchMode="true"

            android:nextFocusRight="@+id/tv"

            android:textColor="#ffffff" />