Android TextSwitcher - 文本切换器

图片的切换可以使用ImageSwitcher来实现，同样文本的切换动画也可以使用Android TextSwitcher类，他们都继承ViewSwitcher类。

ViewSwitcher仅仅包含子类型TextView。TextSwitcher被用来使屏幕上的label产生动画效果。每当setText(CharSequence)被调用时，TextSwitcher使用动画方式将当前的文字内容消失并显示新的文字内容。

package com.android.study;

import java.util.Timer;
import java.util.TimerTask;

import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.animation.AnimationUtils;
import android.widget.Button;
import android.widget.TextSwitcher;
import android.widget.TextView;
import android.widget.ViewSwitcher.ViewFactory;

public class TextSwitcherActivity extends Activity implements ViewFactory {
    /** Called when the activity is first created. */
    TextSwitcher switcher;
    Handler handler;
    String[] resources = { " ", "身是菩提树，", "心如明镜台，", "时时勤拂拭，", "勿使惹尘埃。" };
    private Handler mHandler = new Handler() {

        public void handleMessage(Message msg) {
            switch (msg.what) {
            case 1:
                id = next(); // 更新Id值
                updateText(); // 更新TextSwitcherd显示内容;
                break;
            }
        };
    };
    int id = 0; // resources 数组的Id;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        init();
        Timer timer = new Timer();
        timer.scheduleAtFixedRate(new MyTask(), 1, 3000);// 每3秒更新
    }

    private void init() {
        switcher = (TextSwitcher) findViewById(R.id.switcher);
        switcher.setFactory(this);
        switcher.setInAnimation(AnimationUtils.loadAnimation(this,
                android.R.anim.fade_in));
        switcher.setOutAnimation(AnimationUtils.loadAnimation(this,
                android.R.anim.fade_out));
    }

    private int next() {

        int flag = id + 1;
        if (flag > resources.length - 1) {
            flag = flag - resources.length;
        }
        return flag;
    }

    private void updateText() {
        switcher.setText(resources[id]);
    }

    @Override
    public View makeView() {
        // TODO Auto-generated method stub
        TextView tv = new TextView(this);
        tv.setText(resources[id]);
        return tv;
    }

    private class MyTask extends TimerTask {
        @Override
        public void run() {
            Message message = new Message();
            message.what = 1;
            mHandler.sendMessage(message);

        }
    }
}