实现一个广告栏（上下滚动的textView）

主要用的是android自带的TextSwitcher，很好用，结合着动画效果。

首先是布局

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <RelativeLayout
        android:background="#aaafff"
        android:gravity="center"
        android:layout_gravity="center"
        android:layout_width="match_parent"
        android:layout_height="40dp">
        <ImageView
            android:src="@mipmap/home_sign"
            android:id="@+id/imag"
            android:layout_width="40dp"
            android:layout_height="40dp" />
        <TextSwitcher
            android:layout_marginLeft="10dp"
            android:layout_centerVertical="true"
            android:layout_toRightOf="@id/imag"
            android:id="@+id/tv_switcher"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content">
        </TextSwitcher>
    </RelativeLayout>


</LinearLayout>

然后是activity

package com.example.myapplication.custView;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.TextSwitcher;
import android.widget.TextView;
import android.widget.ViewSwitcher;
import com.example.myapplication.R;
import java.util.ArrayList;
/**
 * Created by pw on 2019/4/2 13:46
 * E-Mail Address: pw163.com
 */
public class Custom_Activity extends AppCompatActivity {
    private TextSwitcher tv_switcher;
    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_cus);
        initView();
    }
    private void initView() {
        tv_switcher = findViewById(R.id.tv_switcher);
        tv_switcher.setFactory(new ViewSwitcher.ViewFactory() {
            @Override
            public View makeView() {
                return new TextView(Custom_Activity.this);
            }
        });
        ArrayList<String> alist = new ArrayList<>();
        alist.clear();
        for (int i = 0; i < 10; i++) {
            alist.add("我是"+i);
        }
        new TextSwitcherAnimation(tv_switcher,alist).create();
    }
}

然后是工具类（实现动画效果）

package com.example.myapplication.custView;
import android.os.Handler;
import android.util.Log;
import android.view.animation.AlphaAnimation;
import android.view.animation.Animation;
import android.view.animation.AnimationSet;
import android.view.animation.TranslateAnimation;
import android.widget.TextSwitcher;
import java.util.List;
/**
 * Created by pw on 2019/4/2 14:08
 * E-Mail Address: pw163.com
 */
public class TextSwitcherAnimation {
    private static final int DURATION = 1000;
    private TextSwitcher textSwitcher;
    private List<String> texts;
    private int marker;
    private AnimationSet InAnimationSet;
    private AnimationSet OutAnimationSet;
    private int delayTime = 2000;
    private Handler handler = new Handler();
    private Runnable task = new Runnable() {
        @Override
        public void run() {
            nextView();
            handler.postDelayed(task, delayTime * 2);
        }
    };

    public TextSwitcherAnimation(TextSwitcher textSwitcher, List<String> texts) {
        this.textSwitcher = textSwitcher;
        this.texts = texts;
    }

    public void start() {
        stop();
        handler.postDelayed(task, delayTime);
    }

    public void stop(){
        handler.removeCallbacks(task);
    }

    public int getMarker() {
        return marker;
    }

    public TextSwitcherAnimation setTexts(List<String> texts) {
        this.texts = texts;
        return this;
    }

    public void setDelayTime(int delayTime) {
        this.delayTime = delayTime;
    }

    public void create() {
        marker = 0;
        if (texts == null){
            Log.w("TextSwitcherAnimation", "texts is null");
            return;
        }
        if (textSwitcher == null) {
            Log.w("TextSwitcherAnimation", "textSwitcher is null");
            return;
        }
        textSwitcher.setText(texts.get(0));
        createAnimation();
        textSwitcher.setInAnimation(InAnimationSet);
        textSwitcher.setOutAnimation(OutAnimationSet);
        start();
    }

    private void createAnimation() {
        AlphaAnimation alphaAnimation;
        TranslateAnimation translateAnimation;

        int h = textSwitcher.getHeight();
        if (h <= 0) {
            textSwitcher.measure(0,0);
            h = textSwitcher.getMeasuredHeight();
        }

        InAnimationSet = new AnimationSet(true);
        OutAnimationSet = new AnimationSet(true);

        alphaAnimation = new AlphaAnimation(0,1);
        translateAnimation = new TranslateAnimation(Animation.ABSOLUTE, 0, Animation.ABSOLUTE, 0,
                Animation.ABSOLUTE, h, Animation.ABSOLUTE, 0);
        InAnimationSet.addAnimation(alphaAnimation);
        InAnimationSet.addAnimation(translateAnimation);
        InAnimationSet.setDuration(DURATION);

        alphaAnimation = new AlphaAnimation(1,0);
        translateAnimation = new TranslateAnimation(Animation.ABSOLUTE, 0, Animation.ABSOLUTE, 0,
                Animation.ABSOLUTE, 0, Animation.ABSOLUTE, -h);
        OutAnimationSet.addAnimation(alphaAnimation);
        OutAnimationSet.addAnimation(translateAnimation);
        OutAnimationSet.setDuration(DURATION);
    }
    private void nextView() {
        marker = ++marker % texts.size();
        textSwitcher.setText(texts.get(marker));
    }
}