http://www.oschina.net/code/snippet_731007_24519
Android自定义的TabBar，自定义了几个属性，可以在xml布局文件中使用，Tab的标题、图标等属性可以在布局文件中完成配置，Java代码中只需要指定Tab跳转的监听接口。可以在所有Android版本使用，建议配合ViewPager使用。
attrs.xml
<?xml version="1.0" encoding="utf-8"?>
<resources>
<declare-styleable name="TabBar">
<attr name="icons" format="reference" />
<!-- icons是一个存放drawable资源文件名的数组 -->
<attr name="titles" format="reference" />
<!-- titles是一个存放string的数组 -->
<attr name="IconAboveTitle" format="boolean" />
<!-- 允许指定分隔线的drawable -->
<attr name="Seperator" format="reference" />
</declare-styleable>
</resources>
TabBar.java
package com.pupa.common.widget;
import com.pupa.common.util.StringHelper;
import com.pupa.TabBarDemo.R;
import android.annotation.SuppressLint;
import android.content.Context;
import android.content.res.Resources;
import android.content.res.TypedArray;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Rect;
import android.graphics.drawable.Drawable;
import android.util.AttributeSet;
import android.view.Display;
import android.view.Gravity;
import android.view.View;
import android.view.WindowManager;
import android.widget.ImageView;
import android.widget.ImageView.ScaleType;
import android.widget.LinearLayout;
import android.widget.TextView;
public class TabBar extends LinearLayout {
private static final String TAG = "TabBar";
private final TabBar mTabBar; // 自己
private final Context mContext;
private final AttributeSet mAttrs;
private int mDefStyle;
private Paint mPaint;
private int mCurrentTabMaskColor;
private int mCurrentTabMaskAlpha;
private String mResPackageName;
private CharSequence[] mTitles;
private CharSequence[] mIconNames;
private Drawable[] mIcons;
private Drawable mSeperator;
private int mSeperatorResId;
private int mSeperatorWidth;
private boolean mIconAboveTitle;
private int mCurrentTabIndex;
private int mTabCount;
private int mTabWidth;
private int mPosition;
private OnCurrentTabChangedListener mTabChangedListener;
public static final int POSITION_TOP = 1; // 位于顶部或者底部
public static final int POSITION_BOTTOM = 2;
public TabBar(Context context) {
this(context, null);
// TODO Auto-generated constructor stub
}
public TabBar(Context context, AttributeSet attrs) {
super(context, attrs);
setWillNotDraw(false); // 重要!!!
mContext = context;
mAttrs = attrs;
mCurrentTabIndex = -1;
mTabCount = 0;
mSeperatorWidth = 0;
mPosition = POSITION_TOP;
mCurrentTabMaskColor = Color.BLACK;
mCurrentTabMaskAlpha = 0x5f;
mPaint = new Paint();
mTabBar = this;
init();
// TODO Auto-generated constructor stub
}
@SuppressWarnings("deprecation")
public void init() {
getResourcesFromXml();
this.setOrientation(LinearLayout.HORIZONTAL);
this.setPadding(0, 0, 0, 0);
WindowManager wm = (WindowManager) mContext
.getSystemService(Context.WINDOW_SERVICE);
Display dp = wm.getDefaultDisplay();
mTabWidth = dp.getWidth();
mTabCount = mTitles.length;
if (mTabCount > 0) {
if (mSeperator != null) {
Bitmap bmp = BitmapFactory.decodeResource(getResources(),
mSeperatorResId);
mSeperatorWidth = bmp.getWidth();
mTabWidth = mTabWidth - (mTabCount - 1) * mSeperatorWidth;
bmp.recycle();
bmp = null;
}
mTabWidth = mTabWidth / mTabCount; // 计算每个tab的宽度
mCurrentTabIndex = 0;
}
LayoutParams inParams = new LayoutParams(LayoutParams.MATCH_PARENT,
LayoutParams.WRAP_CONTENT);
LayoutParams outParams = new LayoutParams(mTabWidth,
LayoutParams.WRAP_CONTENT);
LayoutParams params = new LayoutParams(LayoutParams.WRAP_CONTENT,
LayoutParams.WRAP_CONTENT);
View.OnClickListener clkListener = new View.OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
int index = (Integer) v.getTag();
if (index != mCurrentTabIndex) {
if (mTabChangedListener != null)
mTabChangedListener.onCurrentTabChanged(index);
mCurrentTabIndex = index;
mTabBar.invalidate();
}
}
};
//逐个添加Tab
for (int i = 0; i < mTabCount; ++i) {
LinearLayout tab = new LinearLayout(mContext);
tab.setOrientation(LinearLayout.VERTICAL);
tab.setPadding(0, 0, 0, 0);
tab.setTag(i); // 设置内部标号
tab.setClickable(true);
ImageView imv = new ImageView(mContext);
imv.setScaleType(ScaleType.CENTER);
if (i < mIcons.length)
imv.setImageDrawable(mIcons[i]);
TextView tv = new TextView(mContext);
tv.setGravity(Gravity.CENTER_HORIZONTAL);
tv.setText(mTitles[i]);
if (mIconAboveTitle) { // 图标在标题之上
tab.addView(imv, inParams);
tab.addView(tv, inParams);
} else { // 标题在图标之上
tab.addView(tv, inParams);
tab.addView(imv, inParams);
}
tab.setOnClickListener(clkListener);
this.addView(tab, outParams);
if (mSeperator != null && i < mTabCount - 1) {
ImageView sep = new ImageView(mContext);
sep.setImageDrawable(mSeperator);
this.addView(sep, params);
}
}
}
/**
* 设置当前Tab的序号
*
* @param index
* 你想指定的Tab的序号
*/
public void setCurrentTab(int index) {
if (index > -1 && index < mTabCount&&index!=mCurrentTabIndex) {
mCurrentTabIndex = index;
this.invalidate();
if (mTabChangedListener != null)
mTabChangedListener.onCurrentTabChanged(mCurrentTabIndex);
}
}
public void setOnCurrentTabChangedListener(
OnCurrentTabChangedListener listener) {
mTabChangedListener = listener;
}
/**
* 设置TabBar在顶端还是底端.真实位置由你的Activity的布局文件决定，这里仅仅是作一个标识， 根据这个信息可以增加一些自定义的效果
*
* @param i
* 顶端TabBar.POSITION_TOP或底端TabBar.POSITION_BOTTOM
*/
public void setTabBarPosition(int i) {
mPosition = i;
}
/**
* 设定工程中R.java文件的包名，因为在解析出各个Tab的icon时要用到。如果是默认值则无需指定
*
* @param name
* R.java文件的包名
*/
public void setResourcesPackageName(String name) {
mResPackageName = name;
}
/**
* 设置Tab选中后的颜色，默认alpha为0x5f
*
* @param c
* rgb颜色值
*/
public void setCurrentTabMaskColor(int rgb) {
mCurrentTabMaskColor = rgb;
}
/**
* 设置Tab选中后的颜色.为什么要重载这个方法呢？因为我总是记不住Alpha值0和255谁是全透明， 于是宁愿把ARGB颜色中A跟RGB分开设置。。
*
* @param rgb
* rgb颜色值
* @param a
* alpha值
*/
public void setCurrentTabMaskColor(int rgb, int a) {
mCurrentTabMaskColor = rgb;
mCurrentTabMaskAlpha = a;
}
/**
* 获取Tab个数
*
* @return Tab个数
*/
public int getTabCount() {
return mTabCount;
}
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
int h = this.getHeight();
if (mCurrentTabIndex > -1 && mCurrentTabIndex < mTabCount) {
int startX = (mTabWidth + mSeperatorWidth) * mCurrentTabIndex;
mPaint.setColor(mCurrentTabMaskColor);
mPaint.setAlpha(mCurrentTabMaskAlpha);
mPaint.setStyle(Paint.Style.FILL);
canvas.drawRect(new Rect(startX, 0, startX + mTabWidth, h), mPaint);
}
}
/**
* 从布局文件的属性值中解析出各个资源
*/
private void getResourcesFromXml() {
TypedArray ta = mContext.obtainStyledAttributes(mAttrs,
R.styleable.TabBar, 0, 0);
mIconNames = ta.getTextArray(R.styleable.TabBar_icons);
mTitles = ta.getTextArray(R.styleable.TabBar_titles);
mIconAboveTitle = ta
.getBoolean(R.styleable.TabBar_IconAboveTitle, true);
mSeperator = ta.getDrawable(R.styleable.TabBar_Seperator);
mSeperatorResId = ta.getResourceId(R.styleable.TabBar_Seperator, -1);
if (!StringHelper.notNullAndNotEmpty(mResPackageName))
mResPackageName = mContext.getPackageName();
if (mTitles == null) {
mTitles = new CharSequence[0]; // 避免为null
}
if (mIconNames == null) {
mIconNames = new CharSequence[0]; // 避免为null
}
Resources res = mContext.getResources();
mIcons = new Drawable[mIconNames.length];
for (int i = 0; i < mIconNames.length; ++i) {
int id = res.getIdentifier(mIconNames[i].toString(), "drawable",
mResPackageName);
if (id != 0)
mIcons[i] = res.getDrawable(id);
}
ta.recycle();
}
public interface OnCurrentTabChangedListener {
public void onCurrentTabChanged(int index);
}
}
arrays.xml
<?xml version="1.0" encoding="utf-8"?>
<resources>
<string-array name="tab_titles">
<item>Tab1</item>
<item>Tab2</item>
</string-array>
<string-array name="tab_icons">
<item>tab1_icon</item>
<item>tab2_icon</item>
</string-array>
</resources>
activity_main.xml
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
xmlns:pupa="http://schemas.android.com/apk/res/com.pupa.TabDemo"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity" >
<com.pupa.common.widget.TabBar
android:id="@+id/MainTabBar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:background="@android:drawable/title_bar"
pupa:Seperator="@drawable/tab_seperator"
pupa:icons="@array/tab_icons"
pupa:titles="@array/tab_titles" >
</com.pupa.common.widget.TabBar>
<android.support.v4.view.ViewPager
android:id="@+id/MainViewPager"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_below="@id/MainTabBar" />
</RelativeLayout>