Android App中制作仿MIUI的Tab切换效果的实例分享

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
  xmlns:tools="http://schemas.android.com/tools" 
  xmlns:zhy="http://schemas.android.com/apk/res/com.example.demo_zhy_mms_miui" 
  android:layout_width="match_parent" 
  android:layout_height="match_parent" 
  android:background="#ffffffff" 
  android:orientation="vertical" > 
 
  <com.example.demo_zhy_mms_miui.ViewPagerIndicator 
    android:id="@+id/id_indicator" 
    android:layout_width="match_parent" 
    android:layout_height="45dp" 
    android:background="@drawable/title_bar_bg_one_row" 
    android:orientation="horizontal" 
    zhy:item_count="3" > 
    
  </com.example.demo_zhy_mms_miui.ViewPagerIndicator> 
 
  <android.support.v4.view.ViewPager 
    android:id="@+id/id_vp" 
    android:layout_width="match_parent" 
    android:layout_height="0dp" 
    android:layout_weight="1" > 
  </android.support.v4.view.ViewPager> 
 
</LinearLayout> 

package com.example.demo_zhy_mms_miui; 
 
import java.util.ArrayList; 
import java.util.Arrays; 
import java.util.List; 
 
import android.os.Bundle; 
import android.support.v4.app.Fragment; 
import android.support.v4.app.FragmentActivity; 
import android.support.v4.app.FragmentPagerAdapter; 
import android.support.v4.view.ViewPager; 
import android.view.Window; 
 
public class MainActivity extends FragmentActivity 
{ 
  private List<Fragment> mTabContents = new ArrayList<Fragment>(); 
  private FragmentPagerAdapter mAdapter; 
  private ViewPager mViewPager; 
// private List<String> mDatas = Arrays.asList("短信1", "短信2", "短信3", "短信4", 
//     "短信5", "短信6", "短信7", "短信8", "短信9"); 
  private List<String> mDatas = Arrays.asList("短信", "收藏", "推荐"); 
 
  private ViewPagerIndicator mIndicator; 
 
  @Override 
  protected void onCreate(Bundle savedInstanceState) 
  { 
    super.onCreate(savedInstanceState); 
    requestWindowFeature(Window.FEATURE_NO_TITLE); 
    setContentView(R.layout.vp_indicator); 
 
    initView(); 
    initDatas(); 
    //设置Tab上的标题 
    mIndicator.setTabItemTitles(mDatas); 
    mViewPager.setAdapter(mAdapter); 
    //设置关联的ViewPager 
    mIndicator.setViewPager(mViewPager,0); 
 
  } 
 
  private void initDatas() 
  { 
 
    for (String data : mDatas) 
    { 
      VpSimpleFragment fragment = VpSimpleFragment.newInstance(data); 
      mTabContents.add(fragment); 
    } 
 
    mAdapter = new FragmentPagerAdapter(getSupportFragmentManager()) 
    { 
      @Override 
      public int getCount() 
      { 
        return mTabContents.size(); 
      } 
 
      @Override 
      public Fragment getItem(int position) 
      { 
        return mTabContents.get(position); 
      } 
    }; 
  } 
 
  private void initView() 
  { 
    mViewPager = (ViewPager) findViewById(R.id.id_vp); 
    mIndicator = (ViewPagerIndicator) findViewById(R.id.id_indicator); 
  } 
  
} 

//设置Tab上的标题
mIndicator.setTabItemTitles(mDatas);
//设置关联的ViewPager
mIndicator.setViewPager(mViewPager,0);

package com.example.demo_zhy_mms_miui; 
 
import android.os.Bundle; 
import android.support.v4.app.Fragment; 
import android.view.Gravity; 
import android.view.LayoutInflater; 
import android.view.View; 
import android.view.ViewGroup; 
import android.widget.TextView; 
 
public class VpSimpleFragment extends Fragment 
{ 
  public static final String BUNDLE_TITLE = "title"; 
  private String mTitle = "DefaultValue"; 
 
  @Override 
  public View onCreateView(LayoutInflater inflater, ViewGroup container, 
      Bundle savedInstanceState) 
  { 
    Bundle arguments = getArguments(); 
    if (arguments != null) 
    { 
      mTitle = arguments.getString(BUNDLE_TITLE); 
    } 
 
    TextView tv = new TextView(getActivity()); 
    tv.setText(mTitle); 
    tv.setGravity(Gravity.CENTER); 
 
    return tv; 
  } 
 
  public static VpSimpleFragment newInstance(String title) 
  { 
    Bundle bundle = new Bundle(); 
    bundle.putString(BUNDLE_TITLE, title); 
    VpSimpleFragment fragment = new VpSimpleFragment(); 
    fragment.setArguments(bundle); 
    return fragment; 
  } 
} 

<?xml version="1.0" encoding="utf-8"?> 
<resources> 
 
  <attr name="item_count" format="integer"></attr> 
 
  <declare-styleable name="ViewPagerIndicator"> 
    <attr name="item_count" /> 
  </declare-styleable> 
 
</resources> 

public class ViewPagerIndicator extends LinearLayout 
{ 
  /** 
   * 绘制三角形的画笔 
   */ 
  private Paint mPaint; 
  /** 
   * path构成一个三角形 
   */ 
  private Path mPath; 
  /** 
   * 三角形的宽度 
   */ 
  private int mTriangleWidth; 
  /** 
   * 三角形的高度 
   */ 
  private int mTriangleHeight; 
   
  /** 
   * 三角形的宽度为单个Tab的1/6 
   */ 
  private static final float RADIO_TRIANGEL = 1.0f / 6; 
  /** 
   * 三角形的最大宽度 
   */ 
  private final int DIMENSION_TRIANGEL_WIDTH = (int) (getScreenWidth() / 3 * RADIO_TRIANGEL); 
   
   
  /** 
   * 初始时，三角形指示器的偏移量 
   */ 
  private int mInitTranslationX; 
  /** 
   * 手指滑动时的偏移量 
   */ 
  private float mTranslationX; 
 
  /** 
   * 默认的Tab数量 
   */ 
  private static final int COUNT_DEFAULT_TAB = 4; 
  /** 
   * tab数量 
   */ 
  private int mTabVisibleCount = COUNT_DEFAULT_TAB; 
 
  /** 
   * tab上的内容 
   */ 
  private List<String> mTabTitles; 
  /** 
   * 与之绑定的ViewPager 
   */ 
  public ViewPager mViewPager; 
   
  /** 
   * 标题正常时的颜色 
   */ 
  private static final int COLOR_TEXT_NORMAL = 0x77FFFFFF; 
  /** 
   * 标题选中时的颜色 
   */ 
  private static final int COLOR_TEXT_HIGHLIGHTCOLOR = 0xFFFFFFFF; 
 
  public ViewPagerIndicator(Context context) 
  { 
    this(context, null); 
  } 
 
  public ViewPagerIndicator(Context context, AttributeSet attrs) 
  { 
    super(context, attrs); 
 
    // 获得自定义属性，tab的数量 
    TypedArray a = context.obtainStyledAttributes(attrs, 
        R.styleable.ViewPagerIndicator); 
    mTabVisibleCount = a.getInt(R.styleable.ViewPagerIndicator_item_count, 
        COUNT_DEFAULT_TAB); 
    if (mTabVisibleCount < 0) 
      mTabVisibleCount = COUNT_DEFAULT_TAB; 
    a.recycle(); 
 
    // 初始化画笔 
    mPaint = new Paint(); 
    mPaint.setAntiAlias(true); 
    mPaint.setColor(Color.parseColor("#ffffffff")); 
    mPaint.setStyle(Style.FILL); 
    mPaint.setPathEffect(new CornerPathEffect(3)); 
 
  } 

/** 
   * 设置布局中view的一些必要属性；如果设置了setTabTitles，布局中view则无效 
   */ 
  @Override 
  protected void onFinishInflate() 
  { 
    Log.e("TAG", "onFinishInflate"); 
    super.onFinishInflate(); 
 
    int cCount = getChildCount(); 
 
    if (cCount == 0) 
      return; 
 
    for (int i = 0; i < cCount; i++) 
    { 
      View view = getChildAt(i); 
      LinearLayout.LayoutParams lp = (LayoutParams) view 
          .getLayoutParams(); 
      lp.weight = 0; 
      lp.width = getScreenWidth() / mTabVisibleCount; 
      view.setLayoutParams(lp); 
    } 
    // 设置点击事件 
    setItemClickEvent(); 
 
  } 

/** 
   * 设置点击事件 
   */ 
  public void setItemClickEvent() 
  { 
    int cCount = getChildCount(); 
    for (int i = 0; i < cCount; i++) 
    { 
      final int j = i; 
      View view = getChildAt(i); 
      view.setOnClickListener(new OnClickListener() 
      { 
        @Override 
        public void onClick(View v) 
        { 
          mViewPager.setCurrentItem(j); 
        } 
      }); 
    } 
  } 

/** 
   * 初始化三角形的宽度 
   */ 
  @Override 
  protected void onSizeChanged(int w, int h, int oldw, int oldh) 
  { 
    super.onSizeChanged(w, h, oldw, oldh); 
    mTriangleWidth = (int) (w / mTabVisibleCount * RADIO_TRIANGEL);// 1/6 of 
                                    // width 
    mTriangleWidth = Math.min(DIMENSION_TRIANGEL_WIDTH, mTriangleWidth); 
 
    // 初始化三角形 
    initTriangle(); 
 
    // 初始时的偏移量 
    mInitTranslationX = getWidth() / mTabVisibleCount / 2 - mTriangleWidth 
        / 2; 
  } 
   
  /** 
   * 初始化三角形指示器 
   */ 
  private void initTriangle() 
  { 
    mPath = new Path(); 
 
    mTriangleHeight = (int) (mTriangleWidth / 2 / Math.sqrt(2)); 
    mPath.moveTo(0, 0); 
    mPath.lineTo(mTriangleWidth, 0); 
    mPath.lineTo(mTriangleWidth / 2, -mTriangleHeight); 
    mPath.close(); 
  } 

/** 
 * 绘制指示器 
 */ 
@Override 
protected void dispatchDraw(Canvas canvas) 
{ 
  canvas.save(); 
  // 画笔平移到正确的位置 
  canvas.translate(mInitTranslationX + mTranslationX, getHeight() + 1); 
  canvas.drawPath(mPath, mPaint); 
  canvas.restore(); 
 
  super.dispatchDraw(canvas); 
} 

// 设置关联的ViewPager 
public void setViewPager(ViewPager mViewPager, int pos) 
{ 
  this.mViewPager = mViewPager; 
 
  mViewPager.setOnPageChangeListener(new OnPageChangeListener() 
  { 
    @Override 
    public void onPageSelected(int position) 
    { 
      // 设置字体颜色高亮 
      resetTextViewColor(); 
      highLightTextView(position); 
 
      // 回调 
      if (onPageChangeListener != null) 
      { 
        onPageChangeListener.onPageSelected(position); 
      } 
    } 
 
    @Override 
    public void onPageScrolled(int position, float positionOffset, 
        int positionOffsetPixels) 
    { 
      // 滚动 
      scroll(position, positionOffset); 
 
      // 回调 
      if (onPageChangeListener != null) 
      { 
        onPageChangeListener.onPageScrolled(position, 
            positionOffset, positionOffsetPixels); 
      } 
 
    } 
 
    @Override 
    public void onPageScrollStateChanged(int state) 
    { 
      // 回调 
      if (onPageChangeListener != null) 
      { 
        onPageChangeListener.onPageScrollStateChanged(state); 
      } 
 
    } 
  }); 
  // 设置当前页 
  mViewPager.setCurrentItem(pos); 
  // 高亮 
  highLightTextView(pos); 
} 

// 滚动
scroll(position, positionOffset);

/** 
   * 对外的ViewPager的回调接口 
   * 
   * @author zhy 
   * 
   */ 
  public interface PageChangeListener 
  { 
    public void onPageScrolled(int position, float positionOffset, 
        int positionOffsetPixels); 
 
    public void onPageSelected(int position); 
 
    public void onPageScrollStateChanged(int state); 
  } 
 
  // 对外的ViewPager的回调接口 
  private PageChangeListener onPageChangeListener; 
 
  // 对外的ViewPager的回调接口的设置 
  public void setOnPageChangeListener(PageChangeListener pageChangeListener) 
  { 
    this.onPageChangeListener = pageChangeListener; 
  } 

/** 
   * 高亮文本 
   * 
   * @param position 
   */ 
  protected void highLightTextView(int position) 
  { 
    View view = getChildAt(position); 
    if (view instanceof TextView) 
    { 
      ((TextView) view).setTextColor(COLOR_TEXT_HIGHLIGHTCOLOR); 
    } 
 
  } 
 
  /** 
   * 重置文本颜色 
   */ 
  private void resetTextViewColor() 
  { 
    for (int i = 0; i < getChildCount(); i++) 
    { 
      View view = getChildAt(i); 
      if (view instanceof TextView) 
      { 
        ((TextView) view).setTextColor(COLOR_TEXT_NORMAL); 
      } 
    } 
  } 

/** 
   * 指示器跟随手指滚动，以及容器滚动 
   * 
   * @param position 
   * @param offset 
   */ 
  public void scroll(int position, float offset) 
  { 
    /** 
     * <pre> 
     * 0-1:position=0 ;1-0:postion=0; 
     * </pre> 
     */ 
    // 不断改变偏移量，invalidate 
    mTranslationX = getWidth() / mTabVisibleCount * (position + offset); 
 
    int tabWidth = getScreenWidth() / mTabVisibleCount; 
 
    // 容器滚动，当移动到倒数最后一个的时候，开始滚动 
    if (offset > 0 && position >= (mTabVisibleCount - 2) 
        && getChildCount() > mTabVisibleCount) 
    { 
      if (mTabVisibleCount != 1) 
      { 
        this.scrollTo((position - (mTabVisibleCount - 2)) * tabWidth 
            + (int) (tabWidth * offset), 0); 
      } else 
      // 为count为1时 的特殊处理 
      { 
        this.scrollTo( 
            position * tabWidth + (int) (tabWidth * offset), 0); 
      } 
    } 
 
    invalidate(); 
  } 

/** 
   * 设置可见的tab的数量 
   * 
   * @param count 
   */ 
  public void setVisibleTabCount(int count) 
  { 
    this.mTabVisibleCount = count; 
  } 
 
  /** 
   * 设置tab的标题内容 可选，可以自己在布局文件中写死 
   * 
   * @param datas 
   */ 
  public void setTabItemTitles(List<String> datas) 
  { 
    // 如果传入的list有值，则移除布局文件中设置的view 
    if (datas != null && datas.size() > 0) 
    { 
      this.removeAllViews(); 
      this.mTabTitles = datas; 
 
      for (String title : mTabTitles) 
      { 
        // 添加view 
        addView(generateTextView(title)); 
      } 
      // 设置item的click事件 
      setItemClickEvent(); 
    } 
 
  }