自定义列表数据自动循环向下滚动view（类似于通知通报消息）

首先申明，这个自定义View不是本人写的，大神写的，本人仅限学习一级研究使用

直接上代码吧！后面我再解释一遍

 package com.egojit.android.gcoa.views;

 import android.animation.Animator;
 import android.animation.TypeEvaluator;
 import android.animation.ValueAnimator;
 import android.content.Context;
 import android.graphics.Canvas;
 import android.graphics.Color;
 import android.graphics.Paint;
 import android.graphics.Point;
 import android.os.Handler;
 import android.os.Message;
 import android.support.annotation.Nullable;
 import android.util.AttributeSet;
 import android.util.DisplayMetrics;
 import android.view.View;
 import android.view.WindowManager;

 import com.asuka.android.asukaandroid.comm.utils.LogUtil;
 import com.asuka.android.asukaandroid.view.EmptyView;
 import com.egojit.android.gcoa.model.EmptyModel;

 import java.util.List;

 /**
  * Created by Administrator on 2017/4/18 0018.
  */

 public class CustomScorllView extends View {
     private  Context mContext;
     private boolean hasStart=false;
     private List<EmptyModel> sroucesList;
     private double strHeight;
     private Point startPoint;
     private Point endPoint;
     private boolean stop;

     public void setSroucesList(List<EmptyModel> sroucesList) {
         this.sroucesList = sroucesList;
         type=getCurType();
         title=getCurTitle();
         invalidate();
     }

     public CustomScorllView(Context context) {
         super(context);
         mContext=context;
     }

     public CustomScorllView(Context context, @Nullable AttributeSet attrs) {
         super(context, attrs);
         mContext=context;
     }

     public CustomScorllView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
         super(context, attrs, defStyleAttr);
         mContext=context;
     }

     public CustomScorllView(Context context, @Nullable AttributeSet attrs, int defStyleAttr, int defStyleRes) {
         super(context, attrs, defStyleAttr, defStyleRes);
         mContext=context;
     }

     private void startScorll() {
         int   tempY=y;
         Message message=new Message();
         message.obj=tempY;
         handler.sendMessage(message);
     }
     Handler handler=new Handler(){
         @Override
         public void handleMessage(Message msg) {
             super.handleMessage(msg);
              int tempY= (int) msg.obj;
                 y=tempY;

              if (tempY>-50){
                  invalidate();
                  tempY=tempY-1;
                  Message message=new Message();
                  message.obj=tempY;
                  handler.sendMessage(message);
              }
         }
     };
     int start,end;
     public void start(){
         Point startPoint = new Point(start, 50);
         Point endPoint = new Point(end, 50);
         final ValueAnimator animator = ValueAnimator
                 .ofObject(new PointEvaluator(), startPoint, endPoint);
         animator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
             @Override
             public void onAnimationUpdate(ValueAnimator animation) {
                 Point mPoint = ((Point) animation.getAnimatedValue());
                 y=mPoint.x;
                 invalidate();
             }
         });
         animator.addListener(new Animator.AnimatorListener() {
             @Override
             public void onAnimationStart(Animator animation) {

             }

             @Override
             public void onAnimationEnd(Animator animation) {
                 //下一个显示

                 if (  start==baseline){
                     start= (int) (-strHeight/2);
                     end=baseline;
                     EmptyModel model=sroucesList.get(0);
                     sroucesList.remove(0);
                     sroucesList.add(model);
                     type=getCurType();
                     title=getCurTitle();
                     start();
                 }else {
                     start=baseline;
                     end= (int) (getMeasuredHeight()+strHeight/2);
                     new Handler().postDelayed(new Runnable() {
                         @Override
                         public void run() {
                             start();
                         }
                     },4000);
                 }

             }

             @Override
             public void onAnimationCancel(Animator animation) {

             }

             @Override
             public void onAnimationRepeat(Animator animation) {

             }
         });
         animator.setDuration(3000);
         animator.start();
     }
     public void startAnimation() {
        new Handler().postDelayed(new Runnable() {
            @Override
            public void run() {
                hasStart=true;
                type=getCurType();
                title=getCurTitle();
                start=baseline;
                end= (int) (getMeasuredHeight()+strHeight/2);
                 startPoint = new Point(start, 50);
                 endPoint = new Point(end, 50);
                start();
            }
        },4000);
     }

     private String getCurTitle() {
         return sroucesList.get(0).getVar1();
     }

     private String getCurType() {
         return sroucesList.get(0).getVar();
     }

     private String getNextTitle() {
         if (sroucesList.size()==1){
             return sroucesList.get(0).getVar1();
         }else {
             return sroucesList.get(1).getVar1();
         }

     }

     private String getNextType() {
         if (sroucesList.size()==1){
             return sroucesList.get(0).getVar();
         }else {
             return sroucesList.get(1).getVar();
         }
     }

     int baseline=-999;
     int y;
     String type="哈哈哈";
     String title="个囊女女过过过过";
     @Override
     protected void onDraw(Canvas canvas) {
         super.onDraw(canvas);

         Paint redPaint = new Paint();
         redPaint.setAntiAlias(true);
         redPaint.setTextSize(gettextSize(45));
         redPaint.setColor(0xff50a3ef);
         redPaint.setTextAlign(Paint.Align.LEFT);

         Paint blckPaint = new Paint();
         blckPaint.setAntiAlias(true);
         blckPaint.setTextSize(gettextSize(45));
         blckPaint.setColor(Color.BLACK);
         blckPaint.setTextAlign(Paint.Align.LEFT);

         Paint.FontMetricsInt fontMetrics = redPaint.getFontMetricsInt();
         String typeStr="[" + type + "]";
         //直接返回参数字符串所占用的宽度
         float strWidth = redPaint.measureText(typeStr);
         strHeight=getTxtHeight(redPaint)+15;
         if (baseline==-999&&sroucesList!=null){
             baseline = (getMeasuredHeight() - fontMetrics.bottom + fontMetrics.top) / 2 - fontMetrics.top;
             y=baseline;
         }
 //        LogUtil.e("-----------------handler---------"+y);
         canvas.drawText(typeStr, 30  , y  , redPaint);
         canvas.drawText(title, strWidth+60  , y  , blckPaint);

     }
     public double getTxtHeight(Paint mPaint) {
         Paint.FontMetrics fm = mPaint.getFontMetrics();
         return Math.ceil(fm.descent - fm.ascent);
     }
     public class PointEvaluator implements TypeEvaluator<Point> {
         @Override
         public Point evaluate(float fraction, Point startValue, Point endValue) {
 //            LogUtil.e("-----------------fraction---------"+fraction);
             int resultX = (int) (fraction * (endValue.x-startValue.x)+startValue.x);
             int resultY = (int) (fraction * startValue.y);
             return new Point(resultX, resultY);
         }
     }

     @Override
     public void setOnClickListener(@Nullable OnClickListener l) {
         super.setOnClickListener(l);

     }

     public List<EmptyModel> getSroucesList() {
         return sroucesList;
     }

     public float gettextSize(float f){

         int screenWidth =getScreenWidth(mContext);

         float ratioWidth = (float)screenWidth / 1080;

         return Math.round(f * ratioWidth);
     }

     /**
      * 获取屏幕宽度
      *
      * @return
      */
     @SuppressWarnings("deprecation")
     public  int getScreenWidth(Context context) {
         return ((WindowManager) context
                 .getSystemService(Context.WINDOW_SERVICE)).getDefaultDisplay()
                 .getWidth();
     }

 }

主界面布局为

  <com.wangy.views.CustomScorllView
                     android:id="@+id/custom_scorllView"
                     android:layout_width="match_parent"
                     android:layout_height="match_parent"></com.wany.views.CustomScorllView>

那么如何使用呢！

使用起来就很简单了

  List<EmptyModel> alist=new ArrayList<>();
         for (int i=0;i<newsList.size();i++){
             JSONObject object=newsList.getJSONObject(i);
             EmptyModel model=new EmptyModel();
             String fileType=object.getString("fileType");
             String title=object.getString("title");
             String id=object.getString("id");
             model.setVar(fileType);
             model.setVar1(title);
             model.setVar2(id);
             alist.add(model);
         }
         if (alist.size()==0)return;
         custom_scorllView.setSroucesList(alist);
         custom_scorllView.startAnimation();

其中的newsList为列表数据，你可以从接口中取也可以put值，

EmptyModel为一个空model，他是用来直接设置接口参数形成一个model，这样使用起来比较方便

 package com.egojit.android.gcoa.model;

 /**
  * Created by Administrator on 2016-06-14.
  */
 public class EmptyModel extends Entity {
      String var;
     String var1;
     String var2;
     String var3;
     String var4;
     String var11;
     String var12;
     String var13;
     String var14;
     String var5;
     String var15;

     public String getVar5() {
         return var5;
     }

     public void setVar5(String var5) {
         this.var5 = var5;
     }

     public String getVar15() {
         return var15;
     }

     public void setVar15(String var15) {
         this.var15 = var15;
     }

     public String getVar11() {
         return var11;
     }

     public void setVar11(String var11) {
         this.var11 = var11;
     }

     public String getVar12() {
         return var12;
     }

     public void setVar12(String var12) {
         this.var12 = var12;
     }

     public String getVar13() {
         return var13;
     }

     public void setVar13(String var13) {
         this.var13 = var13;
     }

     public String getVar14() {
         return var14;
     }

     public void setVar14(String var14) {
         this.var14 = var14;
     }

     public String getVar1() {
         return var1;
     }

     public void setVar1(String var1) {
         this.var1 = var1;
     }

     public String getVar2() {
         return var2;
     }

     public void setVar2(String var2) {
         this.var2 = var2;
     }

     public String getVar3() {
         return var3;
     }

     public void setVar3(String var3) {
         this.var3 = var3;
     }

     public String getVar4() {
         return var4;
     }

     public void setVar4(String var4) {
         this.var4 = var4;
     }

     public String getVar() {
         return var;
     }

     public void setVar(String var) {
         this.var = var;
     }
 }