ViewPager + HorizontalScrollView 实现可滚动的标签栏

这是一个可滑动的标签栏的自定义控件，参考此文章http://blog.csdn.net/fx_sky/article/details/8990573，我将主要的功能整合成一个类，配上2个特定的布局即可使用。
效果图：





主要布局文件：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<RelativeLayout
android:id="@+id/rl_nav"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_gravity="top" >

<RadioGroup
android:id="@+id/rg_nav_content"
android:layout_width="fill_parent"
android:layout_height="38dip"
android:layout_alignParentTop="true"
android:background="#F2F2F2"
android:orientation="horizontal" >
</RadioGroup>

<ImageView
android:id="@+id/iv_nav_indicator"
android:layout_width="1dip"
android:layout_height="5dip"
android:layout_alignParentBottom="true"
android:background="#FF0000"
android:contentDescription="@string/mygo_share"
android:scaleType="matrix" />
</RelativeLayout>
</LinearLayout>

标签的布局：
sync_nav_radiogroup_item.xml

<?xml version="1.0" encoding="utf-8"?>
<RadioButton xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="0dip"
android:layout_height="fill_parent"
android:background="#F2F2F2"
android:button="@null"
android:checked="true"
android:gravity="center"
android:textSize="15sp" />

以下是工具类代码：

import android.app.Activity;
import android.content.Context;
import android.support.v4.view.ViewPager;
import android.util.AttributeSet;
import android.util.DisplayMetrics;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.view.animation.LinearInterpolator;
import android.view.animation.TranslateAnimation;
import android.widget.HorizontalScrollView;
import android.widget.ImageView;
import android.widget.RadioButton;
import android.widget.RadioGroup;
import android.widget.RadioGroup.OnCheckedChangeListener;

public class SyncHorizontalScrollView extends HorizontalScrollView {

private View view;
private ImageView leftImage;
private ImageView rightImage;
private int windowWitdh = 0;
private Activity mContext;
private RadioGroup rg_nav_content;
private ImageView iv_nav_indicator;
private LayoutInflater mInflater;
private int count;// 屏幕显示的标签个数
private int indicatorWidth;// 每个标签所占的宽度
private int currentIndicatorLeft = 0;// 当前所在标签页面的位移
private ViewPager mViewPager;
private int scrollX;

public SyncHorizontalScrollView(Context context) {
super(context);
// TODO Auto-generated constructor stub
}

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

/**
*
* 方法描述：
* @param mViewPager
* @param leftImage 左箭頭
* @param rightImage 右箭頭
* @param tabTitle 標籤欄的名稱
* @param count 一頁顯示的標籤個數
* @param context
* <pre>
* 修改日期      修改人       修改说明
* 2014-2-17   chen     新建
* </pre>
*/
public void setSomeParam(ViewPager mViewPager, ImageView leftImage,
ImageView rightImage, String[] tabTitle, int count, Activity context) {
this.mContext = context;
this.mViewPager = mViewPager;
// this.view = view;
mInflater = LayoutInflater.from(context);
this.view = mInflater.inflate(R.layout.sync_hsv_item, null);
this.addView(view);
this.leftImage = leftImage;
this.rightImage = rightImage;
DisplayMetrics dm = new DisplayMetrics();
context.getWindowManager().getDefaultDisplay().getMetrics(dm);
windowWitdh = dm.widthPixels;
this.count = count;
indicatorWidth = windowWitdh / count;
init(tabTitle);
}

private void init(String[] tabTitle) {
rg_nav_content = (RadioGroup) view.findViewById(R.id.rg_nav_content);
iv_nav_indicator = (ImageView) view.findViewById(R.id.iv_nav_indicator);
initIndicatorWidth();
initNavigationHSV(tabTitle);
setListener();
}

// 初始化滑动下标的宽
private void initIndicatorWidth() {
ViewGroup.LayoutParams cursor_Params = iv_nav_indicator
.getLayoutParams();
cursor_Params.width = indicatorWidth;
iv_nav_indicator.setLayoutParams(cursor_Params);
}

// 添加顶部标签
private void initNavigationHSV(String[] tabTitle) {
rg_nav_content.removeAllViews();
for (int i = 0; i < tabTitle.length; i++) {
RadioButton rb = (RadioButton) mInflater.inflate(
R.layout.sync_nav_radiogroup_item, null);
rb.setId(i);
rb.setText(tabTitle[i]);
rb.setLayoutParams(new LayoutParams(indicatorWidth,
LayoutParams.MATCH_PARENT));
rg_nav_content.addView(rb);
}
RadioButton rb = (RadioButton) mInflater.inflate(
R.layout.sync_nav_radiogroup_item, null);
rg_nav_content.addView(rb);

}

private void setListener() {
rg_nav_content
.setOnCheckedChangeListener(new OnCheckedChangeListener() {
@Override
public void onCheckedChanged(RadioGroup group, int checkedId) {
if (rg_nav_content.getChildAt(checkedId) != null) {
moveAnimation(checkedId);
mViewPager.setCurrentItem(checkedId); // ViewPager
// 跟随一起 切换
}
}
});
}
//动画移动效果
private void moveAnimation(int checkedId){
TranslateAnimation animation = new TranslateAnimation(currentIndicatorLeft,
indicatorWidth * checkedId,0f, 0f);
animation.setInterpolator(new LinearInterpolator());
animation.setDuration(100);
animation.setFillAfter(true);

// 执行位移动画
iv_nav_indicator.startAnimation(animation);

// 记录当前 下标的距最左侧的 距离
currentIndicatorLeft = indicatorWidth * checkedId;
scrollX = (checkedId > 1 ? currentIndicatorLeft: 0)- indicatorWidth * 2;
this.post(runnable);
}

// 模拟点击事件
public void performLabelClick(int position) {
if (rg_nav_content != null && rg_nav_content.getChildCount() > position) {
((RadioButton) rg_nav_content.getChildAt(position)).performClick();
}
}

private Runnable runnable = new Runnable() {

@Override
public void run() {
// TODO Auto-generated method stub
smoothScrollTo(scrollX, 0);
}
};

// 显示和隐藏左右两边的箭头
protected void onScrollChanged(int l, int t, int oldl, int oldt) {
super.onScrollChanged(l, t, oldl, oldt);
if (!mContext.isFinishing() && view != null && rightImage != null
&& leftImage != null) {
if (view.getWidth() <= windowWitdh) {
leftImage.setVisibility(View.GONE);
rightImage.setVisibility(View.GONE);
} else {
if (l == 0) {
leftImage.setVisibility(View.GONE);
rightImage.setVisibility(View.VISIBLE);
} else if (view.getWidth() - l == windowWitdh) {
leftImage.setVisibility(View.VISIBLE);
rightImage.setVisibility(View.GONE);
} else {
leftImage.setVisibility(View.VISIBLE);
rightImage.setVisibility(View.VISIBLE);
}
}
}
}
public int getIndicatorWidth(){
return indicatorWidth;
}
}

在调用时，先调用setSomeParam方法将需要用的的控件与数据传入，然后控件内部开始初始化。
由于项目有需求，要在进入此控件使用到的页面时，自动定位到某一个标签，在此需使用View.post方法执行HorizontalScrollView 控件的smoothScrollTo方法，才能确保进入页面后标签已定位。原因是scrollTo方法要等到界面显示完毕才能有效，而view.post方法也是在界面刷新完毕之后才执行。
定义一个performLabelClick方法，让外部调用此类来实现相应的页面跳转即可。

不过此处使用时有一个问题，就是从上一级页面跳转至此页面时，无法固定在最后一个标签位，调试时发现虽然执行了performLabelClick方法模拟点击事件，但是监听事件并没有被响应。暂时没找出问题所在。不过用了一个方法来解决此问题，即在调用initNavigationHSV方法添加标签时，为其多加一个空标签，宽度为0即可，这样即可解决标签栏上无法定位到最后一位的问题，因为真正的最后一位实际上是宽度为0的空标签。
如果大家有遇到此问题或是有解决方法，欢迎告知，谢谢。

附上代码下载地址: http://www.oschina.net/code/snippet_1409622_33243