【手把手教】Android 利用Canvas标点画线，并加入位移动画

1.背景

最近由于公司业务需要，需要自己实现一个点画线，移动的需求，这自然就想到了利用Canvas进行描点，画线连线。

过程比较简单，查阅了网上文章，发现写的都特别片面，很多人也会遇到类似需求，这里把整个实现过程讲一下，并且在实现过程遇到的一些小坑讲给大家。

先看效果图

关于上传不了视频这件事，我再好好研究研究。。。

其实点击检索，小人可以按照画好的路线进行移动。

具体代码：

Canvas画点连线

class DrawView extends View {private Boolean bool=false;private String num;public DrawView(Context context) {super(context);}public void setBool(Boolean isdraw,String number){this.bool=isdraw;this.num=number;Log.e("leo","bool:"+bool);}public void DrawLines(Canvas canvas){Log.e("leo","yayyaya"+bool);Paint mPaint3 = new Paint();mPaint3.setAntiAlias(true);mPaint3.setColor(Color.GREEN);mPaint3.setTextSize(36);mPaint3.setStrokeWidth(20);float[] points3=new float[]{450,100,480,350,480,350,330,500,330,500,510,650,510,650,780,800,780,800,450,900,450,900,450,1200,450,1200,550,1400,550,1400,600,1500};canvas.drawLines(points3,mPaint3);}@Overridepublic void onDraw(Canvas canvas) {super.onDraw(canvas);/** 方法 说明 drawRect 绘制矩形 drawCircle 绘制圆形 drawOval 绘制椭圆 drawPath 绘制任意多边形* drawLine 绘制直线 drawPoin 绘制点*/// 创建画笔Paint mPaint = new Paint();mPaint.setStrokeWidth(20);mPaint.setColor(Color.RED);// 设置红色//绘制Cap为BUTT的点Paint mPaint2 = new Paint();mPaint2.setStrokeWidth(40);mPaint2.setColor(Color.BLUE);// 设置红色mPaint2.setStrokeCap(Paint.Cap.ROUND);Paint mPaint3 = new Paint();mPaint3.setAntiAlias(true);mPaint3.setColor(Color.GREEN);mPaint3.setTextSize(36);mPaint3.setStrokeWidth(20);canvas.drawPoints(new float[]{20,100,100,350,150,430,200,510,250,560,350,650,550,730,670,890,750,1000}, mPaint2);canvas.drawPoints(new float[]{170,100,170,200,170,400,170,510,170,730,170,850}, mPaint2);canvas.drawPoints(new float[]{450,100,480,350,330,500,510,650,780,800,450,900,450,1200,550,1400,600,1500}, mPaint2);canvas.drawPoints(new float[]{140,1200,230,1250,370,1140,500,1220,570,1310,680,1280,750,1300,850,1260}, mPaint2);mPaint.setAntiAlias(true);mPaint.setColor(Color.RED);mPaint.setTextSize(36);float[] points=new float[]{20,100,100,350,100,350,150,430,150,430,200,510,200,510,250,560,250,560,350,650,350,650,550,730,550,730,670,890,670,890,750,1000};//至少4个值，即能够绘制一条直线float[] points2=new float[]{170,100,170,200,170,200,170,400,170,400,170,510,170,510,170,730,170,730,170,850};//至少4个值，即能够绘制一条直线//   至少4个值，即能够绘制一条直线canvas.drawLines(points,mPaint);canvas.drawLines(points2,mPaint);float[] points4=new float[]{140,1200,230,1250,230,1250,370,1140,370,1140,500,1220,500,1220,570,1310,570,1310,680,1280,680,1280,750,1300,750,1300,850,1260};//至少4个值，即能够绘制一条直线canvas.drawLines(points4,mPaint);float[] points3=new float[]{450,100,480,350,480,350,330,500,330,500,510,650,510,650,780,800,780,800,450,900,450,900,450,1200,450,1200,550,1400,550,1400,600,1500};canvas.drawLines(points3,mPaint);if (bool==true){if (num.equals("1")){DrawLines(canvas);}else  if (num.equals("2")){//     float[] points=new float[]{20,100,100,350,100,350,150,430,150,430,200,510,200,510,250,560,250,560,350,650,350,650,550,730,550,730,670,890,670,890,750,1000};//至少4个值，即能够绘制一条直线canvas.drawLines(points2,mPaint3);}else if (num.equals("3")){//  float[] points2=new float[]{170,100,170,200,170,200,170,400,170,400,170,510,170,510,170,730,170,730,170,850};//至少4个值，即能够绘制一条直线canvas.drawLines(points,mPaint3);}else if (num.equals("4")){//  float[] points4=new float[]{140,1200,230,1250,230,1250,370,1140,370,1140,500,1220,500,1220,570,1310,570,1310,680,1280,680,1280,750,1300,750,1300,850,1260};//至少4个值，即能够绘制一条直线canvas.drawLines(points4,mPaint3);}}}
}

简单说明一下，就是自定义View，继承View，利用Canvas画点，然后再利用Canvas画线，只要坐标点相同，其实就可以达到连接标记点画线的效果。

MainActivity进行调用

public class MainActivity extends AppCompatActivity {private EditText mEdiet;private Button  mButton;private ImageView mtv;ObjectAnimator  objectAnimatorX,objectAnimatorY;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);initView();}private void initView() {RelativeLayout layout=(RelativeLayout) findViewById(R.id.root);DrawView views=new DrawView(this);views.setMinimumHeight(500);views.setMinimumWidth(300);//通知view组件重绘views.invalidate();layout.addView(views);}

利用平移动画沿线移动

        mEdiet=findViewById(R.id.qd);mButton=findViewById(R.id.qd2);mtv=findViewById(R.id.dw);mButton.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View view) {String number=mEdiet.getText().toString();Log.e("leo","数字："+number);if (number.equals("1")){float [] x= {450,480,330, 510,780,450,450,550,600};float [] y= {100,350,500,650,800,900,1200,1400,1500};startPopsAnimTrans(mtv,x,y);//  float[] points2=new float[]{170,100,170,200,170,200,170,400,170,400,170,510,170,510,170,730,170,730,170,850};//至少4个值，即能够绘制一条直线}else if (number.equals("2")){Log.e("leo","aiaiiai：");float [] x= {170,170,170, 170,170,170};float [] y= {100,200,400,510,730,850};startPopsAnimTrans(mtv,x,y);}//   startPopsAnimTrans(mtv,x,y);TimerTask task = new TimerTask() {@Overridepublic void run() {views.setBool(true,number);views.invalidate();}};Timer timer = new Timer();timer.schedule(task, 18000);}});
//        mtv.setOnClickListener(new View.OnClickListener() {
//            @Override
//            public void onClick(View view) {
//                startPopsAnimTrans(mtv);
//            }
//        });}private void startPopsAnimTrans(ImageView b,float [] x,float [] y){//  if(objectAnimatorX == null){Log.e("leo","执行否："+x.length);//  float [] x= {450,480,330, 510,780,450,450,550,600};//  float [] y= {100,350,500,650,800,900,1200,1400,1500};objectAnimatorX = ObjectAnimator.ofFloat(b,"translationX", x);objectAnimatorX.setDuration(20000);objectAnimatorY = ObjectAnimator.ofFloat(b,"translationY", y);objectAnimatorY.setDuration(20000);//   }objectAnimatorX.start();objectAnimatorY.start();}

这里的Float数组肯定是与那些标记点的（就是画线所经过的点的位置信息）是一致的，小人才能沿着线移动。