仿微信底部TAG完美渐变，tag渐变

仿微信底部TAG完美渐变，tag渐变

viewpager+fragment仿微信底部TAG完美渐变，在图片渐变的同时字的颜色也在变，注意，是渐变哦！

效果图：

activity_main.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:zhy="http://schemas.android.com/apk/res/com.Sing.weixin"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

    <android.support.v4.view.ViewPager
        android:id="@+id/id_viewpager"
        android:layout_width="fill_parent"
        android:layout_height="0dp"
        android:layout_weight="1" >
    </android.support.v4.view.ViewPager>

    <LinearLayout
        android:layout_width="fill_parent"
        android:layout_height="60dp"
        android:background="@drawable/tabbg"
        android:orientation="horizontal" >

        <com.Sing.weixin.ChangeColorIconWithTextView
            android:id="@+id/id_indicator_one"
            android:layout_width="0dp"
            android:layout_height="fill_parent"
            android:layout_weight="1"
            android:padding="5dp"
            zhy:icon="@drawable/ic_menu_start_conversation"
            zhy:text="@string/tab_one"
            zhy:text_size="12sp" />

        <com.Sing.weixin.ChangeColorIconWithTextView
            android:id="@+id/id_indicator_two"
            android:layout_width="0dp"
            android:layout_height="fill_parent"
            android:layout_weight="1"
            android:padding="5dp"
            zhy:icon="@drawable/ic_menu_friendslist"
            zhy:text="@string/tab_two"
            zhy:text_size="12sp" />
    </LinearLayout>

</LinearLayout>

MainActivity.java

package com.Sing.weixin;

import java.lang.reflect.Field;
import java.util.ArrayList;
import java.util.List;

import android.annotation.SuppressLint;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
import android.support.v4.view.ViewPager;
import android.support.v4.view.ViewPager.OnPageChangeListener;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewConfiguration;

@SuppressLint("NewApi")
public class MainActivity extends FragmentActivity implements
		OnPageChangeListener, OnClickListener {
	private ViewPager mViewPager;
	// 选项卡一Fragment
	private FrgReturnVisit returnVisit;

	// 选项卡一Fragment
	private FrgMicroVisit microVisit;

	private List<ChangeColorIconWithTextView> mTabIndicator = new ArrayList<ChangeColorIconWithTextView>();

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

		setOverflowShowingAlways();
		mViewPager = (ViewPager) findViewById(R.id.id_viewpager);
		mViewPager.setAdapter(new MyPagerAdapter(getSupportFragmentManager()));
		initTabIndicator();

		mViewPager.setOnPageChangeListener(this);
 	}

	private void initTabIndicator() {
		ChangeColorIconWithTextView one = (ChangeColorIconWithTextView) findViewById(R.id.id_indicator_one);
		ChangeColorIconWithTextView two = (ChangeColorIconWithTextView) findViewById(R.id.id_indicator_two);

		mTabIndicator.add(one);
		mTabIndicator.add(two);

		one.setOnClickListener(this);
		two.setOnClickListener(this);

		one.setIconAlpha(1.0f);
	}

	@Override
	public void onPageSelected(int arg0) {
	}

	@Override
	public void onPageScrolled(int position, float positionOffset,
			int positionOffsetPixels) {

		if (positionOffset > 0) {
			ChangeColorIconWithTextView left = mTabIndicator.get(position);
			ChangeColorIconWithTextView right = mTabIndicator.get(position + 1);

			left.setIconAlpha(1 - positionOffset);
			right.setIconAlpha(positionOffset);
		}
	}

	@Override
	public void onPageScrollStateChanged(int state) {
	}

	@Override
	public void onClick(View v) {

		resetOtherTabs();

		switch (v.getId()) {
		case R.id.id_indicator_one:
			mTabIndicator.get(0).setIconAlpha(1.0f);
			mViewPager.setCurrentItem(0, false);
			break;
		case R.id.id_indicator_two:
			mTabIndicator.get(1).setIconAlpha(1.0f);
			mViewPager.setCurrentItem(1, false);
			break;
		}

	}

	/**
	 * 重置其他的Tab
	 */
	private void resetOtherTabs() {
		for (int i = 0; i < mTabIndicator.size(); i++) {
			mTabIndicator.get(i).setIconAlpha(0);
		}
	}

	private void setOverflowShowingAlways() {
		try {
			// true if a permanent menu key is present, false otherwise.
			ViewConfiguration config = ViewConfiguration.get(this);
			Field menuKeyField = ViewConfiguration.class.getDeclaredField("sHasPermanentMenuKey");
			menuKeyField.setAccessible(true);
			menuKeyField.setBoolean(config, false);
		} catch (Exception e) {
			e.printStackTrace();
		}
	}

	public class MyPagerAdapter extends FragmentPagerAdapter {

		public MyPagerAdapter(FragmentManager fm) {
			super(fm);
		}

		private final String[] titles = { "选项一", "选项二"};

		@Override
		public CharSequence getPageTitle(int position) {
			return titles[position];
		}

		@Override
		public int getCount() {
			return titles.length;
		}

		@Override
		public Fragment getItem(int position) {
			switch (position) {
			case 0:
				if (returnVisit == null) {
					returnVisit = new FrgReturnVisit();
				}
				return returnVisit;
			case 1:
				if (microVisit == null) {
					microVisit = new FrgMicroVisit();
				}
				return microVisit;
			default:
				return null;
			}
		}
	}
}

ChangeColorIconWithTextView.java

package com.Sing.weixin;

import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Bitmap;
import android.graphics.Bitmap.Config;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.PorterDuff;
import android.graphics.PorterDuffXfermode;
import android.graphics.Rect;
import android.graphics.drawable.BitmapDrawable;
import android.os.Bundle;
import android.os.Looper;
import android.os.Parcelable;
import android.util.AttributeSet;
import android.util.TypedValue;
import android.view.View;

public class ChangeColorIconWithTextView extends View {

	private Bitmap mBitmap;
	private Canvas mCanvas;
	private Paint mPaint;
	/**
	 * 颜色
	 */
	private int mColor = 0xFF45C01A;
	/**
	 * 透明度 0.0-1.0
	 */
	private float mAlpha = 0f;
	/**
	 * 图标
	 */
	private Bitmap mIconBitmap;
	/**
	 * 限制绘制icon的范围
	 */
	private Rect mIconRect;
	/**
	 * icon底部文本
	 */
	private String mText = "demo";
	private int mTextSize = (int) TypedValue.applyDimension(
			TypedValue.COMPLEX_UNIT_SP, 10, getResources().getDisplayMetrics());
	private Paint mTextPaint;
	private Rect mTextBound = new Rect();

	public ChangeColorIconWithTextView(Context context) {
		super(context);
	}

	/**
	 * 初始化自定义属性值
	 * 
	 * @param context
	 * @param attrs
	 */
	public ChangeColorIconWithTextView(Context context, AttributeSet attrs) {
		super(context, attrs);

		// 获取设置的图标
		TypedArray a = context.obtainStyledAttributes(attrs,
				R.styleable.ChangeColorIconView);

		int n = a.getIndexCount();
		for (int i = 0; i < n; i++) {

			int attr = a.getIndex(i);
			switch (attr) {
			case R.styleable.ChangeColorIconView_icon:
				BitmapDrawable drawable = (BitmapDrawable) a.getDrawable(attr);
				mIconBitmap = drawable.getBitmap();
				break;
			case R.styleable.ChangeColorIconView_color:
				mColor = a.getColor(attr, 0x45C01A);
				break;
			case R.styleable.ChangeColorIconView_text:
				mText = a.getString(attr);
				break;
			case R.styleable.ChangeColorIconView_text_size:
				mTextSize = (int) a.get