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;
    }
}