Android 单行文本的跑马灯

最近项目有一个实现跑马灯效果的需求，需求很简单，就是单行文本（只有几个字）无限循环的效果，最开始也是百度和Github上找，找寻半天不是有BUG就是无法达到需求，最后在一位博主jixiaolong<[e-mail]>的github上借鉴了他所写的自定义View，该博主的自定义控件是作为多行文本使用的，但是该控件也有BUG，就是多行文本切换的太不自然，或者说，实际中用不成。因此本文介绍的控件只针对单行文本使用，滑动自然，不反人类，先看下效果：

废话不多说，奉上具体用法，再强调一遍，只适合单行文本！！！！！！！！！！！

1.自定义View

import java.util.List;import android.annotation.SuppressLint;import android.content.Context;import android.graphics.Paint;import android.text.TextUtils.TruncateAt;import android.util.AttributeSet;import android.view.Gravity;import android.widget.TextView;/** * @author jixiaolong<[e-mail]> */@SuppressLint("AppCompatCustomView")public class BulletinView extends TextView implements Runnable{private int currentScrollX;// 当前滚动的位置private boolean isStop = false; private int textWidth; private List<String> mList;private final int REPEAT = 1;private int repeatCount = 0;private int currentNews = 0;public BulletinView(Context context) { super(context); init();// TODO Auto-generated constructor stub } public BulletinView(Context context, AttributeSet attrs) { super(context, attrs); init();} public BulletinView(Context context, AttributeSet attrs, int defStyle) { super(context, attrs, defStyle); init();} public void init(){setClickable(true);setSingleLine(true);setEllipsize(TruncateAt.MARQUEE);setGravity(Gravity.START|Gravity.CENTER_VERTICAL);}public void setData(List<String> mList){if(mList == null || mList.size()==0){return;}this.mList = mList; currentNews = 0;String n = mList.get(currentNews);setText(n);setTag(n);startScroll();}@Overridepublic void setText(CharSequence text, BufferType type) {super.setText(text, type);MeasureTextWidth(); }@Overridepublic void onScreenStateChanged(int screenState) {super.onScreenStateChanged(screenState);if(screenState == SCREEN_STATE_ON){startScroll();}else{stopScroll();}}/**  * 获取文字宽度  */ private void MeasureTextWidth() { Paint paint = this.getPaint(); String str = this.getText().toString(); textWidth = (int) paint.measureText(str); } @Override public void run() { if(textWidth < 1){//title null api error.if(mList != null && mList.size() > 0){nextNews();}else{return;}}currentScrollX += 5;// 滚动速度scrollTo(currentScrollX, 0); if (isStop) { return; }if (getScrollX() >= textWidth) {currentScrollX = -getWidth();if(repeatCount >= REPEAT){//reach max times 我对原文的修改只有这么一点 startif (mList.size()==1){scrollTo(currentScrollX, 0);}else {nextNews();scrollTo(currentScrollX,0);}//我对原文的修改只有这么一点 end}else{repeatCount ++;}}postDelayed(this, 50); }private void nextNews(){repeatCount = 0;currentNews ++;currentNews = currentNews%mList.size();//cycle indexString n = mList.get(currentNews);setText(n);setTag(n);}// 开始滚动 public void startScroll() { isStop = false; this.removeCallbacks(this); post(this); } // 停止滚动 public void stopScroll() { isStop = true; } }

2.xml使用

<?xml version="1.0" encoding="utf-8"?><RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:orientation="vertical" android:layout_width="match_parent"    android:layout_height="match_parent">    <com.anshi.chattraining.BulletinView        android:id="@+id/tv_bulletin"        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:layout_alignParentTop="true"        android:textColor="@android:color/white"        android:padding="10dp"        android:background="#b0000000"        android:textSize="20sp" /></RelativeLayout>
3.Activity使用

import android.os.Bundle;import android.support.annotation.Nullable;import android.support.v7.app.AppCompatActivity;import java.util.ArrayList;import java.util.List;/** * * Created by yulu on 2017/12/12. */public class MarqueeActivity extends AppCompatActivity {    private BulletinView view;    @Override    protected void onCreate(@Nullable Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.marquee_activity);        view = (BulletinView) findViewById(R.id.tv_bulletin);        List<String> mList = new ArrayList<>();        mList.add("今天共找寻成功22对");        view.setData(mList);    }    @Override    protected void onResume() {        view.startScroll();        super.onResume();    }    @Override    protected void onPause() {        view.stopScroll();        super.onPause();    }}
end.........................就这样把，其他的用SurfaceView做的多半都有些问题，还是用TextView做吧。博主原文地址