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

  1 package com.egojit.android.gcoa.views;
  2 
  3 import android.animation.Animator;
  4 import android.animation.TypeEvaluator;
  5 import android.animation.ValueAnimator;
  6 import android.content.Context;
  7 import android.graphics.Canvas;
  8 import android.graphics.Color;
  9 import android.graphics.Paint;
 10 import android.graphics.Point;
 11 import android.os.Handler;
 12 import android.os.Message;
 13 import android.support.annotation.Nullable;
 14 import android.util.AttributeSet;
 15 import android.util.DisplayMetrics;
 16 import android.view.View;
 17 import android.view.WindowManager;
 18 
 19 import com.asuka.android.asukaandroid.comm.utils.LogUtil;
 20 import com.asuka.android.asukaandroid.view.EmptyView;
 21 import com.egojit.android.gcoa.model.EmptyModel;
 22 
 23 import java.util.List;
 24 
 25 /**
 26  * Created by Administrator on 2017/4/18 0018.
 27  */
 28 
 29 public class CustomScorllView extends View {
 30     private  Context mContext;
 31     private boolean hasStart=false;
 32     private List<EmptyModel> sroucesList;
 33     private double strHeight;
 34     private Point startPoint;
 35     private Point endPoint;
 36     private boolean stop;
 37 
 38     public void setSroucesList(List<EmptyModel> sroucesList) {
 39         this.sroucesList = sroucesList;
 40         type=getCurType();
 41         title=getCurTitle();
 42         invalidate();
 43     }
 44 
 45     public CustomScorllView(Context context) {
 46         super(context);
 47         mContext=context;
 48     }
 49 
 50     public CustomScorllView(Context context, @Nullable AttributeSet attrs) {
 51         super(context, attrs);
 52         mContext=context;
 53     }
 54 
 55     public CustomScorllView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
 56         super(context, attrs, defStyleAttr);
 57         mContext=context;
 58     }
 59 
 60     public CustomScorllView(Context context, @Nullable AttributeSet attrs, int defStyleAttr, int defStyleRes) {
 61         super(context, attrs, defStyleAttr, defStyleRes);
 62         mContext=context;
 63     }
 64 
 65     private void startScorll() {
 66         int   tempY=y;
 67         Message message=new Message();
 68         message.obj=tempY;
 69         handler.sendMessage(message);
 70     }
 71     Handler handler=new Handler(){
 72         @Override
 73         public void handleMessage(Message msg) {
 74             super.handleMessage(msg);
 75              int tempY= (int) msg.obj;
 76                 y=tempY;
 77 
 78              if (tempY>-50){
 79                  invalidate();
 80                  tempY=tempY-1;
 81                  Message message=new Message();
 82                  message.obj=tempY;
 83                  handler.sendMessage(message);
 84              }
 85         }
 86     };
 87     int start,end;
 88     public void start(){
 89         Point startPoint = new Point(start, 50);
 90         Point endPoint = new Point(end, 50);
 91         final ValueAnimator animator = ValueAnimator
 92                 .ofObject(new PointEvaluator(), startPoint, endPoint);
 93         animator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
 94             @Override
 95             public void onAnimationUpdate(ValueAnimator animation) {
 96                 Point mPoint = ((Point) animation.getAnimatedValue());
 97                 y=mPoint.x;
 98                 invalidate();
 99             }
100         });
101         animator.addListener(new Animator.AnimatorListener() {
102             @Override
103             public void onAnimationStart(Animator animation) {
104 
105             }
106 
107             @Override
108             public void onAnimationEnd(Animator animation) {
109                 //下一个显示
110 
111                 if (  start==baseline){
112                     start= (int) (-strHeight/2);
113                     end=baseline;
114                     EmptyModel model=sroucesList.get(0);
115                     sroucesList.remove(0);
116                     sroucesList.add(model);
117                     type=getCurType();
118                     title=getCurTitle();
119                     start();
120                 }else {
121                     start=baseline;
122                     end= (int) (getMeasuredHeight()+strHeight/2);
123                     new Handler().postDelayed(new Runnable() {
124                         @Override
125                         public void run() {
126                             start();
127                         }
128                     },4000);
129                 }
130 
131 
132             }
133 
134             @Override
135             public void onAnimationCancel(Animator animation) {
136 
137             }
138 
139             @Override
140             public void onAnimationRepeat(Animator animation) {
141 
142             }
143         });
144         animator.setDuration(3000);
145         animator.start();
146     }
147     public void startAnimation() {
148        new Handler().postDelayed(new Runnable() {
149            @Override
150            public void run() {
151                hasStart=true;
152                type=getCurType();
153                title=getCurTitle();
154                start=baseline;
155                end= (int) (getMeasuredHeight()+strHeight/2);
156                 startPoint = new Point(start, 50);
157                 endPoint = new Point(end, 50);
158                start();
159            }
160        },4000);
161     }
162 
163     private String getCurTitle() {
164         return sroucesList.get(0).getVar1();
165     }
166 
167     private String getCurType() {
168         return sroucesList.get(0).getVar();
169     }
170 
171     private String getNextTitle() {
172         if (sroucesList.size()==1){
173             return sroucesList.get(0).getVar1();
174         }else {
175             return sroucesList.get(1).getVar1();
176         }
177 
178     }
179 
180     private String getNextType() {
181         if (sroucesList.size()==1){
182             return sroucesList.get(0).getVar();
183         }else {
184             return sroucesList.get(1).getVar();
185         }
186     }
187 
188     int baseline=-999;
189     int y;
190     String type="哈哈哈";
191     String title="个囊女女过过过过";
192     @Override
193     protected void onDraw(Canvas canvas) {
194         super.onDraw(canvas);
195 
196         Paint redPaint = new Paint();
197         redPaint.setAntiAlias(true);
198         redPaint.setTextSize(gettextSize(45));
199         redPaint.setColor(0xff50a3ef);
200         redPaint.setTextAlign(Paint.Align.LEFT);
201 
202         Paint blckPaint = new Paint();
203         blckPaint.setAntiAlias(true);
204         blckPaint.setTextSize(gettextSize(45));
205         blckPaint.setColor(Color.BLACK);
206         blckPaint.setTextAlign(Paint.Align.LEFT);
207 
208         Paint.FontMetricsInt fontMetrics = redPaint.getFontMetricsInt();
209         String typeStr="[" + type + "]";
210         //直接返回参数字符串所占用的宽度
211         float strWidth = redPaint.measureText(typeStr);
212         strHeight=getTxtHeight(redPaint)+15;
213         if (baseline==-999&&sroucesList!=null){
214             baseline = (getMeasuredHeight() - fontMetrics.bottom + fontMetrics.top) / 2 - fontMetrics.top;
215             y=baseline;
216         }
217 //        LogUtil.e("-----------------handler---------"+y);
218         canvas.drawText(typeStr, 30  , y  , redPaint);
219         canvas.drawText(title, strWidth+60  , y  , blckPaint);
220 
221     }
222     public double getTxtHeight(Paint mPaint) {
223         Paint.FontMetrics fm = mPaint.getFontMetrics();
224         return Math.ceil(fm.descent - fm.ascent);
225     }
226     public class PointEvaluator implements TypeEvaluator<Point> {
227         @Override
228         public Point evaluate(float fraction, Point startValue, Point endValue) {
229 //            LogUtil.e("-----------------fraction---------"+fraction);
230             int resultX = (int) (fraction * (endValue.x-startValue.x)+startValue.x);
231             int resultY = (int) (fraction * startValue.y);
232             return new Point(resultX, resultY);
233         }
234     }
235 
236     @Override
237     public void setOnClickListener(@Nullable OnClickListener l) {
238         super.setOnClickListener(l);
239 
240     }
241 
242     public List<EmptyModel> getSroucesList() {
243         return sroucesList;
244     }
245 
246     public float gettextSize(float f){
247 
248 
249         int screenWidth =getScreenWidth(mContext);
250 
251         float ratioWidth = (float)screenWidth / 1080;
252 
253 
254         return Math.round(f * ratioWidth);
255     }
256 
257     /**
258      * 获取屏幕宽度
259      *
260      * @return
261      */
262     @SuppressWarnings("deprecation")
263     public  int getScreenWidth(Context context) {
264         return ((WindowManager) context
265                 .getSystemService(Context.WINDOW_SERVICE)).getDefaultDisplay()
266                 .getWidth();
267     }
268 
269 }

主界面布局为

1  <com.wangy.views.CustomScorllView
2                     android:id="@+id/custom_scorllView"
3                     android:layout_width="match_parent"
4                     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

 1  List<EmptyModel> alist=new ArrayList<>();
 2         for (int i=0;i<newsList.size();i++){
 3             JSONObject object=newsList.getJSONObject(i);
 4             EmptyModel model=new EmptyModel();
 5             String fileType=object.getString("fileType");
 6             String title=object.getString("title");
 7             String id=object.getString("id");
 8             model.setVar(fileType);
 9             model.setVar1(title);
10             model.setVar2(id);
11             alist.add(model);
12         }
13         if (alist.size()==0)return;
14         custom_scorllView.setSroucesList(alist);
15         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

  1 package com.egojit.android.gcoa.model;
  2 
  3 
  4 /**
  5  * Created by Administrator on 2016-06-14.
  6  */
  7 public class EmptyModel extends Entity {
  8      String var;
  9     String var1;
 10     String var2;
 11     String var3;
 12     String var4;
 13     String var11;
 14     String var12;
 15     String var13;
 16     String var14;
 17     String var5;
 18     String var15;
 19 
 20     public String getVar5() {
 21         return var5;
 22     }
 23 
 24     public void setVar5(String var5) {
 25         this.var5 = var5;
 26     }
 27 
 28     public String getVar15() {
 29         return var15;
 30     }
 31 
 32     public void setVar15(String var15) {
 33         this.var15 = var15;
 34     }
 35 
 36     public String getVar11() {
 37         return var11;
 38     }
 39 
 40     public void setVar11(String var11) {
 41         this.var11 = var11;
 42     }
 43 
 44     public String getVar12() {
 45         return var12;
 46     }
 47 
 48     public void setVar12(String var12) {
 49         this.var12 = var12;
 50     }
 51 
 52     public String getVar13() {
 53         return var13;
 54     }
 55 
 56     public void setVar13(String var13) {
 57         this.var13 = var13;
 58     }
 59 
 60     public String getVar14() {
 61         return var14;
 62     }
 63 
 64     public void setVar14(String var14) {
 65         this.var14 = var14;
 66     }
 67 
 68     public String getVar1() {
 69         return var1;
 70     }
 71 
 72     public void setVar1(String var1) {
 73         this.var1 = var1;
 74     }
 75 
 76     public String getVar2() {
 77         return var2;
 78     }
 79 
 80     public void setVar2(String var2) {
 81         this.var2 = var2;
 82     }
 83 
 84     public String getVar3() {
 85         return var3;
 86     }
 87 
 88     public void setVar3(String var3) {
 89         this.var3 = var3;
 90     }
 91 
 92     public String getVar4() {
 93         return var4;
 94     }
 95 
 96     public void setVar4(String var4) {
 97         this.var4 = var4;
 98     }
 99 
100     public String getVar() {
101         return var;
102     }
103 
104     public void setVar(String var) {
105         this.var = var;
106     }
107 }