Android实现网易新闻客户端效果

下面来简单实现一下网易新闻客户端左右切换的效果，当然实际项目上肯定不能这样写，还有很多需要优化的地方。

activity_main.xml

[html] view
plaincopyprint?

1. <?xml version="1.0" encoding="utf-8"?>
2. <TabHost xmlns:android="http://schemas.android.com/apk/res/android"
3. android:id="@android:id/tabhost"
4. android:layout_width="match_parent"
5. android:layout_height="match_parent" >
6. <LinearLayout
7. android:layout_width="match_parent"
8. android:layout_height="match_parent"
9. android:orientation="vertical" >
10. <TabWidget
11. android:id="@android:id/tabs"
12. android:layout_width="match_parent"
13. android:layout_height="wrap_content"
14. android:orientation="horizontal" />
15. <FrameLayout
16. android:id="@android:id/tabcontent"
17. android:layout_width="match_parent"
18. android:layout_height="match_parent"/>
19. <!--   <FrameLayout
20. android:id="@+id/real_tabcontent"
21. android:layout_width="match_parent"
22. android:layout_height="0dp"
23. android:layout_weight="0"/> -->
24. </LinearLayout>
25. </TabHost>

Java实现逻辑

package com.jackie.neteasedemo;

import android.os.Bundle;
import android.app.Activity;
import android.app.Fragment;
import android.app.FragmentTransaction;
import android.content.Context;
import android.text.TextUtils;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewConfiguration;
import android.widget.ImageView;
import android.widget.TabHost;
import android.widget.TabHost.OnTabChangeListener;

public class MainActivity extends Activity {

	private TabHost mTabHost;
	private Fragment mFragment;

	private float startX = 0;
	private float endX = 0;
	private int touchSlop;

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

		mTabHost = (TabHost) findViewById(android.R.id.tabhost);
		mTabHost.setup();
		mTabHost.setOnTabChangedListener(new OnTabChangeListener() {

			@Override
			public void onTabChanged(String tabId) {
				System.out.println("current tabid=" + tabId);
				FragmentTransaction ft = getFragmentManager()
						.beginTransaction();
				if (TextUtils.equals("first", tabId)) {
					// add/replace fragment first
					mFragment = new Fragment1();
					System.out.println("Load Frament1");
				} else if (TextUtils.equals("second", tabId)) {
					// add/replace fragment second
					mFragment = new Fragment2();
					System.out.println("Load Frament2");
				} else if (TextUtils.equals("third", tabId)) {
					// add/replace fragment third
					mFragment = new Fragment3();
					System.out.println("Load Frament3");
				}
				ft.replace(android.R.id.tabcontent, mFragment);
				ft.commit();
			}
		});

		mTabHost.addTab(mTabHost.newTabSpec("first").setIndicator("First")
				.setContent(new DummyTabFactory(this)));
		mTabHost.addTab(mTabHost.newTabSpec("second").setIndicator("Second")
				.setContent(new DummyTabFactory(this)));
		mTabHost.addTab(mTabHost.newTabSpec("third").setIndicator("Third")
				.setContent(new DummyTabFactory(this)));

		touchSlop = ViewConfiguration.get(this).getScaledTouchSlop(); //默认是8，能够根据不同分辨率适配而改变
	}

	@Override
	public boolean onTouchEvent(MotionEvent event) {
		switch (event.getAction()) {
		case MotionEvent.ACTION_DOWN:
			startX = event.getX();
			break;
		case MotionEvent.ACTION_UP:
			endX = event.getX();
			break;
		default:
			break;
		}

		if (endX - startX > touchSlop) { // 向右滑动
			if (TextUtils.equals(mTabHost.getCurrentTabTag(), "third")) {
				mFragment = new Fragment2();
				mTabHost.setCurrentTabByTag("second");
			} else if (TextUtils.equals(mTabHost.getCurrentTabTag(), "second")) {
				mFragment = new Fragment1();
				mTabHost.setCurrentTabByTag("first");
			}

			FragmentTransaction ft = getFragmentManager().beginTransaction();
			ft.replace(android.R.id.tabcontent, mFragment);
			ft.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_FADE);
			ft.commit();
		} else if (Math.abs(endX - startX) > touchSlop) { // 向左滑动
			if (TextUtils.equals(mTabHost.getCurrentTabTag(), "first")) {
				mFragment = new Fragment2();
				mTabHost.setCurrentTabByTag("second");
			} else if (TextUtils.equals(mTabHost.getCurrentTabTag(), "second")) {
				mFragment = new Fragment3();
				mTabHost.setCurrentTabByTag("third");
			}

			FragmentTransaction ft = getFragmentManager().beginTransaction();
			ft.replace(android.R.id.tabcontent, mFragment);
			ft.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_FADE);
			ft.commit();
		}
		return super.onTouchEvent(event);
	}

	private class DummyTabFactory implements TabHost.TabContentFactory {
		private Context context;

		public DummyTabFactory(Context ctx) {
			this.context = ctx;
		}

		@Override
		public View createTabContent(String tag) {// 创建宽高均为0的view
			View v = new ImageView(context);
			v.setMinimumWidth(0);
			v.setMinimumHeight(0);
			return v;
		}
	}
}

效果如下：