<resources>
  <declare-styleable name="topbar">
    <attr name="title" format="string"/>
    <attr name="titleBacgroud" format="reference|color"/>
    <attr name="titleSize" format="dimension"></attr>

    <attr name="leftBtnTitle" format="string"></attr>
    <attr name="leftBtnColor" format="color"></attr>
    <attr name="leftBtnSize" format="dimension"></attr>

    <attr name="rightBtnTitle" format="string"></attr>
    <attr name="rightBtnColor" format="color"></attr>
    <attr name="rightBtnSize" format="dimension"></attr>

  </declare-styleable>

public class TopBar extends RelativeLayout{

  private Button leftBtn, rightBtn;
  private TextView tvTitle;

  private String title;
  private float titleSize ;
  private Drawable titleBackground;

  private String leftBtnTitle;
  private int leftBtnColor;
  private float leftBtnSize;

  private String rightBtnTitle;
  private int rightBtnColor;
  private float rightBtnSize;

  private LayoutParams leftBtnParams ,righBtnParams,titleParams;

  /**
   * 为TopBar添加回调点击事件,好处是不需要每次都修改TopBar中的点击事件，只需修改从外面传进来的Listener的点击事件
   * @param context
   * @param attrs
   */

  public interface topbarClickListener{
    void leftBtnClick();
    void rightBtnClick();
  }

  private topbarClickListener listener;

  public void setTopbarClickListener(topbarClickListener ls){
    this.listener = ls;
  }

  public TopBar(Context context, AttributeSet attrs) {
    super(context, attrs);
    // TODO Auto-generated constructor stub


    TypedArray ta = context.obtainStyledAttributes(attrs, R.styleable.topbar);

    title = ta.getString(R.styleable.topbar_title);
    titleSize = ta.getDimension(R.styleable.topbar_titleSize, 0);
    titleBackground = ta.getDrawable(R.styleable.topbar_titleBacgroud);

    leftBtnTitle = ta.getString(R.styleable.topbar_leftBtnTitle);
    leftBtnColor = ta.getColor(R.styleable.topbar_leftBtnColor, 0);
    leftBtnSize = ta.getDimension(R.styleable.topbar_leftBtnSize, 0);

    rightBtnTitle = ta.getString(R.styleable.topbar_rightBtnTitle);
    rightBtnColor = ta.getColor(R.styleable.topbar_rightBtnColor, 0);
    rightBtnSize = ta.getDimension(R.styleable.topbar_rightBtnSize, 0);

    ta.recycle();//资源回收

    tvTitle = new TextView(context);
    leftBtn = new Button(context);
    rightBtn = new Button(context);

    tvTitle.setText(title);
    tvTitle.setTextSize(titleSize);
    tvTitle.setBackground(titleBackground);

    leftBtn.setText(leftBtnTitle);
    leftBtn.setTextColor(leftBtnColor);
    leftBtn.setTextSize(leftBtnSize);

    rightBtn.setText(rightBtnTitle);
    rightBtn.setTextColor(rightBtnColor);
    rightBtn.setTextSize(rightBtnSize);

    setBackgroundColor(Color.DKGRAY);//设置整个背景色

    /**
     * 将3个控件进行布局
     */
    //左边的按钮位于父布局的左边，通过addRule(RelativeLayout.ALIGN_PARENT_LEFT);来实现
    leftBtnParams = new LayoutParams(RelativeLayout.LayoutParams.WRAP_CONTENT,
        RelativeLayout.LayoutParams.WRAP_CONTENT);
    leftBtnParams.addRule(RelativeLayout.ALIGN_PARENT_LEFT);
    leftBtnParams.setMargins(0, 18, 0, 0);
    addView(leftBtn, leftBtnParams);

    righBtnParams = new LayoutParams(RelativeLayout.LayoutParams.WRAP_CONTENT,
        RelativeLayout.LayoutParams.WRAP_CONTENT);
    righBtnParams.addRule(RelativeLayout.ALIGN_PARENT_RIGHT);
    righBtnParams.setMargins(0, 18, 0, 0);
    addView(rightBtn, righBtnParams);
    //中间的TextView位于父布局的中间，addRule(RelativeLayout.CENTER_IN_PARENT);
    titleParams = new LayoutParams(RelativeLayout.LayoutParams.WRAP_CONTENT,
        RelativeLayout.LayoutParams.MATCH_PARENT);
    titleParams.addRule(RelativeLayout.CENTER_IN_PARENT);

    tvTitle.setGravity(Gravity.CENTER);

    addView(tvTitle, titleParams);


    leftBtn.setOnClickListener(new OnClickListener() {

      @Override
      public void onClick(View v) {
        // TODO Auto-generated method stub
        listener.leftBtnClick();
      }
    });


    rightBtn.setOnClickListener(new OnClickListener() {

      @Override
      public void onClick(View v) {
        // TODO Auto-generated method stub
        listener.rightBtnClick();
      }
    });

  }

  public void setTvTitle(String value){
    tvTitle.setText(value);
  }

}

leftBtn.setOnClickListener(new OnClickListener() {

      @Override
      public void onClick(View v) {
        // TODO Auto-generated method stub
        //listener.leftBtnClick();//回调实现
        Toast.makeText(context, "LEFT BUTTOM CLICK", Toast.LENGTH_SHORT).show();
      }
    });


    rightBtn.setOnClickListener(new OnClickListener() {

      @Override
      public void onClick(View v) {
        // TODO Auto-generated method stub
        //listener.rightBtnClick();//回调实现
        Toast.makeText(context, "RIGHT BUTTOM CLICK", Toast.LENGTH_SHORT).show();
      }
    });

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
  xmlns:custom="http://schemas.android.com/apk/res/com.example.viewpagerdemo"
  android:layout_width="match_parent"
  android:layout_height="match_parent"
  android:orientation="vertical" >

  <com.example.viewpagerdemo.view.TopBar 
    android:id="@+id/topbar"
    android:layout_width="match_parent"
    android:layout_height="100dp"
    custom:title="网易新闻"
    custom:titleBacgroud="#ff2255"
    custom:titleSize="30sp"
    custom:leftBtnTitle="BACK"
    custom:leftBtnColor="#ff4400"
    custom:leftBtnSize="24sp"
    custom:rightBtnTitle="MORE"
    custom:rightBtnColor="#ff4400"
    custom:rightBtnSize="24sp"
    ></com.example.viewpagerdemo.view.TopBar>

</LinearLayout>

public class TopBarActivity extends Activity{

  private TopBar mTopBar;

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    // TODO Auto-generated method stub
    super.onCreate(savedInstanceState);
    requestWindowFeature(Window.FEATURE_NO_TITLE);

    setContentView(R.layout.topbar_layout);

    mTopBar = (TopBar) findViewById(R.id.topbar);

    /**
     * 利用回调实现TopBar的点击事件
     */
    mTopBar.setTopbarClickListener(new topbarClickListener() {

      @Override
      public void rightBtnClick() {
        // TODO Auto-generated method stub
        Toast.makeText(TopBarActivity.this, "RIGHT BUTTOM CLICK", Toast.LENGTH_SHORT).show();
      }

      @Override
      public void leftBtnClick() {
        // TODO Auto-generated method stub
        Toast.makeText(TopBarActivity.this, "LEFT BUTTOM CLICK", Toast.LENGTH_SHORT).show();
      }
    });

    //更改TopBar中显示的标题
    mTopBar.setTvTitle("凤凰网");

  }
}