Android ViewPager实现Tabhost选项卡底部滑块动态滑动过渡

小鱼儿 2023-10-16 21:19 20阅读 0赞

**《Android ViewPager实现Tabhost选项卡底部滑块动态滑动过渡》**

之前基于github上的第三方开源控件ViewPagerIndicator的UnderlinePageIndicator（原文链接：[http://blog.csdn.net/zhangphil/article/details/44752213][http_blog.csdn.net_zhangphil_article_details_44752213]），自己写了一个底部带有滑块、且当ViewPager页面切换时候选项卡也随之相应切换，且滑块也随之相应动态滑动效果得控件。但写的太过于紧耦合，不利于复用，所以现在重构了代码，重写了代码，把这些效果做成了一个自定制的松耦合控件：TabLinearLayout，该控件可以在未来的项目中直接拿出使用。

控件效果图如图所示：

![Center][]

测试用的MainActivity.java：

package zhangphil.view;
    
    import java.util.ArrayList;
    
    import zhangphil.underline.R;
    
    import com.viewpagerindicator.UnderlinePageIndicator;
    
    import android.support.v4.app.Fragment;
    import android.support.v4.app.FragmentManager;
    import android.support.v4.app.FragmentPagerAdapter;
    import android.support.v4.view.PagerAdapter;
    import android.support.v4.view.ViewPager;
    import android.support.v7.app.ActionBarActivity;
    import android.view.Gravity;
    import android.view.LayoutInflater;
    import android.view.View;
    import android.view.ViewGroup;
    import android.widget.ArrayAdapter;
    import android.widget.TextView;
    import android.content.Context;
    import android.graphics.Color;
    import android.os.Bundle;
    
    /**
     * 基于第三方开源控件ViewPagerIndicator的UnderlinePageIndicator，自己写的一个在选项卡底部有衬线的滑动控件。
     * 控件效果图如图所示。 这里面有一个特别的效果是：头部的选项卡在ViewPager切换过程中，底部的滑块也随之动态渐渐滑动过渡。
     * 
     * */
    
    public class MainActivity extends ActionBarActivity {
    
    	private TabLinearLayout mTabLinearLayout;
    	private ArrayList<Fragment> mArryList;
    	private ViewPager mPager;
    
    	// 未被选中的选项卡字体颜色
    	private int COLOR_NORMAL = Color.DKGRAY;
    
    	@Override
    	protected void onCreate(Bundle savedInstanceState) {
    		super.onCreate(savedInstanceState);
    		setContentView(R.layout.activity_main);
    
    		mArryList = new ArrayList<Fragment>();
    		// 初始化5个Fragment作为测试。
    		for (int i = 0; i < 5; i++) {
    			TestFragment f = (TestFragment) TestFragment.newInstance();
    			f.id = i;
    			mArryList.add(f);
    		}
    
    		PagerAdapter mAdapter = new MyFragmentAdapter(
    				getSupportFragmentManager());
    
    		mPager = (ViewPager) findViewById(R.id.pager);
    		mPager.setAdapter(mAdapter);
    
    		UnderlinePageIndicator mIndicator = (UnderlinePageIndicator) findViewById(R.id.indicator);
    		mIndicator.setViewPager(mPager);
    		mIndicator.setFades(false);
    		mIndicator.setSelectedColor(0xff33B5E5);
    
    		mTabLinearLayout = (TabLinearLayout) findViewById(R.id.tab_LinearLayout);
    
    		ArrayAdapter mTabLinearLayoutAdapter = new MyTabLinearLayoutAdapter(
    				this, -1);
    		mTabLinearLayout.initialization(mPager, mTabLinearLayoutAdapter,
    				mIndicator);
    	}
    
    	private class MyTabLinearLayoutAdapter extends ArrayAdapter {
    		private Context context;
    
    		public MyTabLinearLayoutAdapter(Context context, int resource) {
    			super(context, resource);
    			this.context = context;
    		}
    
    		@Override
    		public int getCount() {
    			return mArryList.size();
    		}
    
    		// 在这里仅仅返回一个TextView作为选项卡的View。
    		// 此处可以返回更丰富的View。
    		@Override
    		public View getView(int position, View convertView, ViewGroup parent) {
    
    			TextView v = new TextView(context);
    			v.setGravity(Gravity.CENTER);
    			v.setText("选项卡" + position);
    			v.setTextColor(COLOR_NORMAL);
    
    			return v;
    		}
    	}
    
    	// 仅仅用于测试的Fragment，用一个id标识。
    	private static class TestFragment extends Fragment {
    
    		public int id;
    
    		public static Fragment newInstance() {
    			return new TestFragment();
    		}
    
    		public View onCreateView(LayoutInflater inflater, ViewGroup container,
    				Bundle savedInstanceState) {
    
    			TextView v = new TextView(getActivity());
    			v.setGravity(Gravity.CENTER);
    			v.setTextSize(50f);
    			v.setText("Fragment: " + id);
    
    			return v;
    		}
    	}
    
    	private class MyFragmentAdapter extends FragmentPagerAdapter {
    
    		public MyFragmentAdapter(FragmentManager fm) {
    			super(fm);
    		}
    
    		@Override
    		public Fragment getItem(int position) {
    			return mArryList.get(position);
    		}
    
    		@Override
    		public int getCount() {
    			return mArryList.size();
    		}
    	}
    }

MainActivity.java需要的activity\_main.xml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" >
    
        <zhangphil.view.TabLinearLayout
            android:id="@+id/tab_LinearLayout"
            android:layout_width="match_parent"
            android:layout_height="30dip"
            android:orientation="horizontal" />
    
        <com.viewpagerindicator.UnderlinePageIndicator
            android:id="@+id/indicator"
            android:layout_width="match_parent"
            android:layout_height="7px" />
    
        <View
            android:layout_width="match_parent"
            android:layout_height="1px"
            android:background="#33B5E5" />
    
        <android.support.v4.view.ViewPager
            android:id="@+id/pager"
            android:layout_width="match_parent"
            android:layout_height="0dp"
            android:layout_weight="1" />
    
    </LinearLayout>

自己重写的TabLinearLayout.java：

package zhangphil.view;
    
    import com.viewpagerindicator.PageIndicator;
    
    import android.content.Context;
    import android.graphics.Color;
    import android.support.v4.view.ViewPager;
    import android.util.AttributeSet;
    import android.view.View;
    import android.widget.ArrayAdapter;
    import android.widget.LinearLayout;
    import android.widget.TextView;
    
    public class TabLinearLayout extends LinearLayout {
    
    	private int COLOR_NORMAL = Color.DKGRAY;
    	private ArrayAdapter mAtapter;
    	private ViewPager mPager;
    	private TabLinearLayoutListener mTabLinearLayoutListener;
    
    	public TabLinearLayout(Context context, AttributeSet attrs) {
    		super(context, attrs);
    	}
    
    	public TabLinearLayout(Context context) {
    		super(context);
    	}
    
    	public void initialization(ViewPager mPager, ArrayAdapter mAtapter,
    			PageIndicator mPageIndicator) {
    		this.mAtapter = mAtapter;
    		this.mPager = mPager;
    
    		mPageIndicator
    				.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {
    
    					@Override
    					public void onPageSelected(int pos) {
    						setCurrentItem(pos);
    
    						if (mTabLinearLayoutListener != null)
    							mTabLinearLayoutListener.onTab(pos);
    					}
    
    					@Override
    					public void onPageScrolled(int arg0, float arg1, int arg2) {
    
    					}
    
    					@Override
    					public void onPageScrollStateChanged(int arg0) {
    
    					}
    				});
    
    		// 添加选项卡
    		addIndicators();
    
    		// 初始化，第0项被选中
    		setIndicatorViewSelected(0);
    	}
    
    	public void initialization(ViewPager mPager, ArrayAdapter mAtapter,
    			PageIndicator mPageIndicator,
    			TabLinearLayoutListener mTabLinearLayoutListener) {
    
    		this.mTabLinearLayoutListener = mTabLinearLayoutListener;
    
    		initialization(mPager, mAtapter, mPageIndicator);
    	}
    
    	// 添加Tab选项卡
    	private void addIndicators() {
    		for (int i = 0; i < mAtapter.getCount(); i++) {
    			View v = mAtapter.getView(i, null, null);
    			addIndicatorItem(v, i);
    		}
    	}
    
    	// 在这里设置被选中时候选项卡变化的效果
    	private void setIndicatorViewSelected(int pos) {
    		for (int i = 0; i < super.getChildCount(); i++) {
    			if (i == pos) {
    				View v = super.getChildAt(i);
    				TextView tv = (TextView) v;
    				// Android Holo 样式的蓝色
    				tv.setTextColor(0xff33B5E5);
    			} else {
    				View v = super.getChildAt(i);
    				TextView tv = (TextView) v;
    				tv.setTextColor(COLOR_NORMAL);
    			}
    		}
    	}
    
    	// 在线性布局里面依次添加一个View，为添加的View添加事件。
    	private void addIndicatorItem(View view, final int index) {
    		LayoutParams params = new LayoutParams(LayoutParams.WRAP_CONTENT,
    				LayoutParams.MATCH_PARENT, 1);
    		super.addView(view, index, params);
    		view.setOnClickListener(new View.OnClickListener() {
    
    			@Override
    			public void onClick(View v) {
    
    				// 当用户点击该View时候，设置ViewPager正确而Pager Item
    				if (mTabLinearLayoutListener != null)
    					mTabLinearLayoutListener.onTab(v, index);
    
    				// 设置ViewPager的显示项。
    				mPager.setCurrentItem(index, true);
    				setCurrentItem(index);
    			}
    		});
    	}
    
    	// 设置当前LinearLayout的pos项子view被选中。
    	public void setCurrentItem(int pos) {
    		setIndicatorViewSelected(pos);
    	}
    
    	// 一个接口，当用户点击选项卡时候，方法被回调。
    	public interface TabLinearLayoutListener {
    		public void onTab(View v, int pos);
    
    		public void onTab(int pos);
    	}
    }

[http_blog.csdn.net_zhangphil_article_details_44752213]: http://blog.csdn.net/zhangphil/article/details/44752213
[Center]: https://img-blog.csdn.net/20150331112451968?watermark/2/text/aHR0cDovL2Jsb2cuY3Nkbi5uZXQvemhhbmdwaGls/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70/gravity/Center