Use the android control TextSwitcher to scroll up and down Textview,

Use the android control TextSwitcher to scroll up and down Textview,

You can often see many up and down textviews on the app, which can be directly implemented using TextSwitcher.
At first, I wrote a custom view for implementation, and then found that the official(: Invalid "parameters).

Controls include ImageSwitcher and ViewSwitcher. TextSwitcher and ImageSwitcher both inherit from ViewSwitcher, so the methods used are the same, but the objects are different.

Effect

Only a little gif is captured.

Use Layout

Place a TextSwitcher directly.

Called in activity

TextSwitcher textSwitcher = (TextSwitcher) findViewById (R. id. textSwitcher); textSwitcher. setFactory (new ViewSwitcher. viewFactory () {@ Override public View makeView () {return new TextView (context) ;}}); List
 
  
Texts = new ArrayList <> (); for (int I = 0; I <10; I ++) {texts. add ("loop ..... "+ I);} textSwitcher. setText (texts. get (0 ));
 

The simplest way to set attributes is to rewrite ViewFactory. Other ImageSwitcher and ViewSwitcher are the same, but the view setting is different!

When a loop is required, you only need to set a Handler to change the value in the setText of textSwitcher each time.
For example

    private Handler handler = new Handler();    private Runnable task = new Runnable() {        @Override        public void run() {            marker = ++marker % texts.size();            textSwitcher.setText(texts.get(marker));            handler.postDelayed(task, 4000);        }    };

In

textSwitcher.setInAnimation();textSwitcher.setOutAnimation();

Method to Control the input and output animations of textSwitcher

Implement animation switching and Automatic loop

Create a class to uniformly manage textSwitcher animations and loops

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;/** * TextSwitcherAnimation * Author: gjn. * Time: 2018/2/22. */public class TextSwitcherAnimation {    private static final int DURATION = 1000;    private TextSwitcher textSwitcher;    private List
 
   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
  
    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
   
     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));    }}
   
  
 

The implementation is simple, that is, an in and out animation and Handler are made to control the loop. I will not repeat it here.

Use the following

List
 
  
Texts = new ArrayList <> (); for (int I = 0; I <10; I ++) {texts. add ("loop ..... "+ I);} textSwitcher. setFactory (new ViewSwitcher. viewFactory () {@ Override public View makeView () {TextView t = new TextView (mContext); return t ;}}); new TextSwitcherAnimation (textSwitcher, texts ). create ();