Android之 Canvas绘制

一 Canvas介绍

1.1 Canvas 是绘制图形的重要类之一，它可以在 View 或 SurfaceView 上绘制各种图形和文本.

1.2 要创建 Canvas，首先需要有一个 View 或 SurfaceView 对象，在 View 或 SurfaceView 的绘制方法中，可以通过 Canvas 的锁定方法来获取一个 Canvas 对象，然后在 Canvas 对象上进行绘制。

二 Paint画笔

2.1 新建画笔

Paint paint=new Paint();

2.2  设置样式（填充或描边）

paint.setStyle(Paint.Style.FILL_AND_STROKE);

2.3 设置画笔颜色

paint.setColor(Color.RED);

2.4  设置线条宽度

paint.setStrokeWidth(4);

2.5  开启抗锯齿功能

paint.setAntiAlias(true);

2.6 绘制虚线

PathEffect effects = new DashPathEffect(new float[]{5, 10}, 0);
paint.setPathEffect(effects);

 2.7 绘制渐变

int[] mColors = {Color.parseColor("#FF9800"),Color.parseColor("#FFCE85"),Color.parseColor("#FFEBCF")};
LinearGradient linearGradient=new LinearGradient(50, 0, 50, heightSize, mColors, null, Shader.TileMode.MIRROR);
paint.setShader(linearGradient);

2.8 设置线条链接处样式

paint.setStrokeJoin(Paint.Join.ROUND);

 2.9 设置线头模式为圆角

paint.setStrokeCap(Paint.Cap.ROUND);

2.10  设置字体风格会粗体

paint.setTypeface(Typeface.DEFAULT_BOLD);

 2.11 设置图层混合模式

paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_IN));

2.11 设置特殊效果，比如模糊效果 

MaskFilter blur = new BlurMaskFilter(10, BlurMaskFilter.Blur.NORMAL);paint.setMaskFilter(blur);
paint.setMaskFilter(blur);

三 Canvas画布

3.1 新建画布

Canvas canvas=new Canvas();

3.2 画线

canvas.drawLine(float startX ,float  startY ,float endX ,float endY ,Paint paint);

3.3 画方形

canvas.drawRect(float left ,float top ,float  right ,float bottom ,Paint paint);

3.4 画圆角矩形

canvas.drawRoundRect(float left, float top, float right, float bottom, float rx, float ry,paint)

3.5 画圆形

canvas.drawCircle(float cX ,float cY ,float redius ,Paint paint);

3.6 画扇形

canvas.drawArc(float left, float top, float right, float bottom, float startAngle,float sweepAngle, boolean useCenter, @NonNull Paint paint);

3.7 绘制一个点

canvas.drawPoint(float x, float y , Paint paint)

3.8 绘制颜色

canvas.drawColor(@ColorInt int color)

3.9 绘制字体

canvas.rawText(tring text, float x, float y, paint)

3.10 绘制路径

canvas.drawPath(Path path, paint)

3.11 绘制Bitmap

canvas.drawBitmap(Bitmap bitmap, float left, float top, Paint paint)

3.12 保存画布

canvas.save(int saveFlags)

3.12 恢复画布

canvas.restore()

3.14 保存图层

canvas.saveLayer(RectF bounds, Paint paint, int saveFlags)

3.15 画布平移

canvas.translate(float dx, float dy)

3.16 画布缩放

canvas.scale(float sx, float sy)

3.17 画布旋转

canvas.rotate(float degrees)

3.18 画布倾斜

canvas.skew(float sx, float sy)

四 实例-基础图形绘制

4.1 定义属性文件arrts.xml

<?xml version="1.0" encoding="utf-8"?>
<resources><declare-styleable name="CavasBaseView"><attr name="paint_color" format="color" /><attr name="default_width" format="dimension" /><attr name="default_height" format="dimension" /></declare-styleable>
</resources>

4.2 新建View，CanvasBaseView.java

package com.juai.canvastest;import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.LinearGradient;
import android.graphics.Paint;
import android.graphics.Path;
import android.graphics.RectF;
import android.graphics.Shader;
import android.util.AttributeSet;
import android.util.Log;
import android.view.View;import androidx.annotation.Nullable;public class CanvasBaseView extends View {private static final String TAG = "CanvasBaseView";//默认属性private int paintColor;private int defaultWidth;private int defaultHeight;public CanvasBaseView(Context context) {super(context);}public CanvasBaseView(Context context, @Nullable AttributeSet attrs) {super(context, attrs);}public CanvasBaseView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {super(context, attrs, defStyleAttr);//默认属性TypedArray array = context.obtainStyledAttributes(attrs, R.styleable.CavasBaseView);paintColor = array.getColor(R.styleable.CavasBaseView_paint_color, Color.RED);defaultWidth = array.getColor(R.styleable.CavasBaseView_default_width, 0);defaultHeight = array.getColor(R.styleable.CavasBaseView_default_height,0);array.recycle();}//    @Overrideprotected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {// 自己算的画 没有必要再让 view 自己测量一遍了，浪费资源// super.onMeasure(widthMeasureSpec, heightMeasureSpec);int widthMode = MeasureSpec.getMode(widthMeasureSpec);   //获取宽的模式int widthSize = MeasureSpec.getSize(widthMeasureSpec);   //获取宽的尺寸int heightMode = MeasureSpec.getMode(heightMeasureSpec); //获取高的模式int heightSize = MeasureSpec.getSize(heightMeasureSpec); //获取高的尺寸Log.d(TAG, "宽的模式:"+widthMode);Log.d(TAG, "宽的尺寸:"+widthSize);Log.d(TAG, "高的模式:"+heightMode);Log.d(TAG, "高的尺寸:"+heightSize);// 开始计算宽度int widthResult = 0;switch (widthMode) {case MeasureSpec.AT_MOST://不超过// 在 AT_MOST 模式下，取二者的最小值//widthSize测量的实际宽高，widthResult期望的最大宽高widthResult=Math.min(widthSize,defaultWidth);break;case MeasureSpec.EXACTLY://精准的// 父 View 给多少用多少widthResult = widthSize;break;case MeasureSpec.UNSPECIFIED://无限大，没有指定大小// 默认的大小widthResult = defaultWidth;break;default:widthResult = 0;break;}// 开始计算宽度int heightResult = 0;switch (widthMode) {case MeasureSpec.AT_MOST://不超过// 在 AT_MOST 模式下，取二者的最小值// heightSize测量的实际宽高，heightResult期望的最大宽高heightResult=Math.min(heightSize,heightResult);break;case MeasureSpec.EXACTLY://精准的// 父 View 给多少用多少heightResult = heightSize;break;case MeasureSpec.UNSPECIFIED://无限大，没有指定大小// 使用计算出的大小heightResult = heightResult;break;default:heightResult = 0;break;}// 设置最终的宽高setMeasuredDimension(widthResult, heightResult);}//   //上面模版代码其实 Android SDK 里面早就有了很好的封装 ： resolveSize(int size, int measureSpec) 和 resolveSizeAndState(int size, int measureSpec, int childMeasuredState) ，两行代码直接搞定。
//    @Override
//    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
//        // 没有必要再让 view 自己测量一遍了，浪费资源
//        // super.onMeasure(widthMeasureSpec, heightMeasureSpec);
//
//        // 指定期望的 size
//        int width = resolveSize(defaultWidth, widthMeasureSpec);
//        int height = resolveSize(defaultHeight, heightMeasureSpec);
//        // 设置大小
//        setMeasuredDimension(width, height);
//    }@Overrideprotected void onDraw(Canvas canvas) {super.onDraw(canvas);// 创建画笔Paint p = new Paint();p.setColor(Color.RED);// 设置红色p.setTextSize(16);canvas.drawText("画圆：", 10, 20, p);// 画文本canvas.drawCircle(60, 20, 10, p);// 小圆p.setAntiAlias(true);// 设置画笔的锯齿效果。 true是去除canvas.drawCircle(120, 20, 20, p);// 大圆canvas.drawText("画线及弧线：", 10, 60, p);p.setColor(Color.GREEN);// 设置绿色canvas.drawLine(60, 40, 100, 40, p);// 画线canvas.drawLine(110, 40, 190, 80, p);// 斜线//画笑脸弧线p.setStyle(Paint.Style.STROKE);//设置空心RectF oval1=new RectF(150,20,180,40);canvas.drawArc(oval1, 180, 180, false, p);//小弧形oval1.set(190, 20, 220, 40);canvas.drawArc(oval1, 180, 180, false, p);//小弧形oval1.set(160, 30, 210, 60);canvas.drawArc(oval1, 0, 180, false, p);//小弧形canvas.drawText("画矩形：", 10, 80, p);p.setColor(Color.GRAY);// 设置灰色p.setStyle(Paint.Style.FILL);//设置填满canvas.drawRect(60, 60, 80, 80, p);// 正方形canvas.drawRect(60, 90, 160, 100, p);// 长方形canvas.drawText("画扇形和椭圆:", 10, 120, p);Shader mShader = new LinearGradient(0, 0, 100, 100,new int[] { Color.RED, Color.GREEN, Color.BLUE, Color.YELLOW,Color.LTGRAY }, null, Shader.TileMode.REPEAT); // 一个材质,打造出一个线性梯度沿著一条线。p.setShader(mShader);// p.setColor(Color.BLUE);RectF oval2 = new RectF(60, 100, 200, 240);// 设置个新的长方形，扫描测量canvas.drawArc(oval2, 200, 130, true, p);// 画弧，第一个参数是RectF：该类是第二个参数是角度的开始，第三个参数是多少度，第四个参数是真的时候画扇形，是假的时候画弧线//画椭圆，把oval改一下oval2.set(210,100,250,130);canvas.drawOval(oval2, p);canvas.drawText("画三角形：", 10, 200, p);// 绘制这个三角形,你可以绘制任意多边形Path path = new Path();path.moveTo(80, 200);// 此点为多边形的起点path.lineTo(120, 250);path.lineTo(80, 250);path.close(); // 使这些点构成封闭的多边形canvas.drawPath(path, p);// 你可以绘制很多任意多边形，比如下面画六连形p.reset();//重置p.setColor(Color.LTGRAY);p.setStyle(Paint.Style.STROKE);//设置空心Path path1=new Path();path1.moveTo(180, 200);path1.lineTo(200, 200);path1.lineTo(210, 210);path1.lineTo(200, 220);path1.lineTo(180, 220);path1.lineTo(170, 210);path1.close();//封闭canvas.drawPath(path1, p);//画圆角矩形p.setStyle(Paint.Style.FILL);//充满p.setColor(Color.LTGRAY);p.setAntiAlias(true);// 设置画笔的锯齿效果canvas.drawText("画圆角矩形:", 10, 260, p);RectF oval3 = new RectF(80, 260, 200, 300);// 设置个新的长方形canvas.drawRoundRect(oval3, 20, 15, p);//第二个参数是x半径，第三个参数是y半径//画贝塞尔曲线canvas.drawText("画贝塞尔曲线:", 10, 310, p);p.reset();p.setStyle(Paint.Style.STROKE);p.setColor(Color.GREEN);Path path2=new Path();path2.moveTo(100, 320);//设置Path的起点path2.quadTo(150, 310, 170, 400); //设置贝塞尔曲线的控制点坐标和终点坐标canvas.drawPath(path2, p);//画出贝塞尔曲线//画点p.setStyle(Paint.Style.FILL);canvas.drawText("画点：", 10, 390, p);canvas.drawPoint(60, 390, p);//画一个点canvas.drawPoints(new float[]{60,400,65,400,70,400}, p);//画多个点//画图片，就是贴图
//        Bitmap bitmap = BitmapFactory.decodeResource(getResources(), R.mipmap.ic_launcher);
//        canvas.drawBitmap(bitmap, 250,360, p);}
}

4.3 使用自定义view

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"xmlns:app="http://schemas.android.com/apk/res-auto"android:layout_width="match_parent"android:layout_height="match_parent"><com.juai.canvastest.CanvasBaseViewandroid:layout_width="match_parent"android:layout_height="match_parent"app:default_height="300dp"app:default_width="300dp"app:paint_color="#000000" />
</LinearLayout>

public class CanvasBaseActivity extends Activity {@Overrideprotected void onCreate(@Nullable Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_canvas_base);}
}

4.4 效果

 

五  实例-剪切蒙版圆角

5.1 利用setXfermode混合图层裁剪蒙版

public Bitmap getPltMaskingBitmap(float widthMM, float heightMM, int averageRadius) {int dipValue = 300;Bitmap resourceBitmap = BitmapFactory.decodeFile(uvCaseFilePath);Log.e("HHH", "图纸的宽高: " + resourceBitmap.getWidth() + "--" + resourceBitmap.getHeight());int widthPX = (int) ScreenUtils.getApplyDimension(dipValue, widthMM);int heightPX = (int) (resourceBitmap.getHeight()* 1f/ resourceBitmap.getWidth()*widthPX);Bitmap bitmap = Bitmap.createBitmap(widthPX, heightPX, Bitmap.Config.ARGB_8888);Canvas rootCanvas = new Canvas(bitmap);//rootCanvas.drawColor(Color.RED);Paint paint = new Paint();paint.setColor(Color.BLACK);paint.setAntiAlias(true);paint.setStyle(Paint.Style.FILL_AND_STROKE);//绘制蒙版RectF rectF = new RectF(0, 0, widthPX, heightPX);int radius = (int) ScreenUtils.getApplyDimension(dipValue, averageRadius);rootCanvas.drawRoundRect(rectF, radius, radius, paint);//设置混合模式rootCanvas.save();paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_IN));//绘制原图paint.setColor(Color.RED);paint.setAntiAlias(true);paint.setStyle(Paint.Style.FILL);Rect dstRect = new Rect(0, 0, widthPX, heightPX);rootCanvas.drawBitmap(resourceBitmap, null, dstRect, paint);
//        rootCanvas.drawRect(rectF,paint);return bitmap;}

5.2 效果

六 实例-根据图纸坐标集合动画绘制路径Path

6.1 获取坐标集合

;:H A L0 ECN U0,0;P0;U81,95;D81,175;U331,5191;D331,5208;D333,5244;D340,5278;D349,5311;D362,5342;D377,5371;D396,5400;D418,5426;D443,5452;D470,5475;D499,5495;D528,5511;D559,5524;D591,5534;D624,5541;D659,5544;D695,5544;D730,5542;D764,5535;D797,5526;D828,5513;D857,5498;D886,5479;D912,5457;D938,5432;D961,5405;D981,5376;D997,5347;D1010,5316;D1020,5284;D1027,5251;D1030,5216;D1031,5180;D1028,5145;D1021,5111;D1012,5078;D1000,5047;D984,5017;D965,4989;D943,4962;D918,4937;D891,4914;D863,4894;D833,4878;D802,4865;D770,4855;D737,4848;D702,4845;D667,4844;D631,4847;D597,4853;D564,4863;D533,4875;D504,4891;D475,4910;D449,4932;D423,4957;D400,4984;D380,5012;D364,5042;D351,5073;D341,5105;D334,5138;D331,5173;D331,5191;D331,5208;D332,5230;U446,5468;D452,5467;D456,5463;D468,5472;D497,5493;D527,5510;D558,5524;D590,5534;D623,5541;D656,5544;D691,5545;D726,5542;D762,5536;D795,5526;D827,5514;D856,5499;D884,5480;D911,5459;D936,5435;D959,5408;D979,5378;D996,5348;D1010,5317;D1020,5285;D1027,5252;D1030,5219;D1031,5184;D1028,5149;D1022,5113;D1012,5080;D1000,5048;D985,5019;D966,4991;D945,4964;D921,4939;D894,4916;U321,5937;D325,5933;D332,5932;D334,5915;D340,5880;D349,5848;D362,5817;D377,5787;D396,5759;D418,5732;D443,5707;D470,5684;D499,5664;D528,5647;D559,5634;D591,5624;D624,5618;D659,5614;D695,5614;D730,5617;D764,5623;D797,5632;D828,5645;D857,5661;D886,5680;D912,5701;D938,5726;D961,5754;D981,5782;D997,5812;D1010,5843;D1020,5875;D1027,5908;D1030,5942;D1031,5978;D1028,6014;D1021,6048;D1012,6080;D1000,6111;D984,6141;D965,6169;D943,6196;D918,6221;D891,6245;D863,6264;D833,6281;D802,6294;D770,6304;D737,6310;D702,6314;D667,6314;D631,6311;D597,6305;D564,6296;D533,6283;D504,6267;D475,6249;D449,6227;D423,6202;D400,6174;D380,6146;D364,6116;D351,6085;D341,6053;D334,6020;D331,5986;D330,5950;D332,5932;D334,5915;D337,5893;U1237,6092;D1240,6077;D1251,6048;D1268,6022;D1291,5999;D1317,5981;D1346,5969;D1376,5963;D1408,5962;D1440,5968;D1468,5979;D1494,5997;D1517,6019;D1536,6045;D1548,6074;D1554,6104;D1554,6136;D1549,6168;D1537,6197;D1520,6222;D1497,6245;D1471,6264;D1443,6276;D1412,6282;D1380,6282;D1348,6277;D1320,6265;D1294,6248;D1271,6226;D1253,6199;D1240,6171;D1234,6140;D1234,6108;D1237,6092;D1240,6077;D1249,6055;U1050,5548;D1046,5547;D1047,5530;D1053,5496;D1063,5463;D1075,5432;D1091,5402;D1110,5374;D1132,5347;D1157,5322;D1184,5299;D1212,5279;D1242,5263;D1273,5250;D1305,5240;D1338,5233;D1372,5230;D1408,5229;D1444,5232;D1478,5238;D1510,5248;D1541,5260;D1571,5276;D1599,5295;D1626,5317;D1652,5342;D1675,5369;D1694,5397;D1711,5427;D1724,5458;D1734,5490;D1740,5523;D1744,5558;D1744,5593;D1741,5629;D1735,5663;D1726,5695;D1713,5727;D1697,5756;D1679,5784;D1657,5811;D1632,5837;D1605,5860;D1576,5879;D1546,5896;D1516,5909;D1483,5919;D1450,5925;D1416,5929;D1380,5929;D1345,5926;D1311,5920;D1278,5911;D1247,5898;D1217,5883;D1189,5864;D1162,5842;D1137,5817;D1114,5790;D1094,5761;D1078,5732;D1064,5701;D1055,5669;D1048,5635;D1044,5601;D1044,5565;D1046,5547;D1047,5530;D1051,5509;U1686,5151;D1681,5151;D1675,5140;D1658,5124;D1636,5115;D1612,5116;D1590,5126;D1573,5143;D1565,5166;D1566,5190;D1575,5212;D1593,5228;D1616,5237;D1640,5236;D1662,5226;D1678,5209;D1687,5186;D1687,5162;D1681,5151;D1675,5140;D1658,5124;D1654,5122;U1225,5011;D1230,5007;D1237,5006;D1240,4991;D1251,4962;D1268,4936;D1291,4913;D1317,4895;D1346,4883;D1376,4877;D1408,4876;D1440,4882;D1469,4893;D1494,4911;D1517,4933;D1536,4959;D1548,4988;D1554,5018;D1554,5050;D1549,5082;D1537,5111;D1520,5136;D1497,5159;D1471,5178;D1443,5190;D1412,5196;D1380,5196;D1349,5191;D1320,5179;D1294,5162;D1271,5140;D1253,5113;D1241,5085;D1234,5054;D1234,5022;D1237,5006;D1240,4991;D1249,4969;U205,5926;D200,5925;D200,5185;D204,5137;D212,5090;D224,5045;D241,5002;D262,4961;D287,4922;D317,4885;D351,4850;D388,4818;D426,4790;D467,4767;D509,4749;D553,4735;D598,4725;D645,4720;D694,4719;D1404,4719;D1453,4723;D1500,4731;D1545,4743;D1587,4760;D1628,4781;D1667,4806;D1704,4836;D1739,4870;D1771,4907;D1799,4945;D1822,4986;D1840,5028;D1854,5072;D1864,5117;D1869,5164;D1870,5213;D1870,5973;D1867,6022;D1859,6069;D1846,6114;D1830,6156;D1809,6197;D1783,6236;D1754,6273;D1720,6309;D1683,6341;D1644,6368;D1604,6391;D1562,6409;D1518,6423;D1472,6433;D1425,6438;D1376,6439;D666,6439;D617,6436;D571,6428;D526,6415;D483,6399;D442,6378;D403,6352;D366,6323;D331,6289;D299,6252;D271,6213;D248,6173;D230,6131;D216,6087;D206,6041;D201,5994;D200,5945;D200,5925;D200,5886;U120,5925;D120,5185;D124,5128;D133,5074;D147,5021;D167,4971;D191,4924;D220,4878;D255,4835;D294,4793;D337,4756;D382,4724;D429,4697;D478,4675;D529,4658;D582,4647;D637,4641;D694,4639;D1404,4639;D1461,4643;D1516,4652;D1568,4666;D1618,4686;D1666,4710;D1711,4739;D1755,4774;D1796,4813;D1834,4856;D1866,4901;D1893,4948;D1915,4997;D1931,5048;D1943,5101;D1949,5156;D1950,5213;D1950,5973;D1946,6030;D1937,6085;D1923,6137;D1904,6187;D1879,6235;D1850,6281;D1816,6324;D1776,6365;D1733,6403;D1688,6435;D1641,6462;D1592,6484;D1541,6500;D1488,6512;D1433,6518;D1376,6519;D666,6519;D609,6515;D555,6506;D502,6492;D452,6473;D404,6449;D359,6419;D315,6385;D274,6345;D237,6302;D205,6257;D178,6210;D156,6161;D139,6110;D128,6057;D121,6002;D120,5945;D120,5925;D120,5886;U81,6027;D81,567;D85,516;D93,467;D106,421;D123,376;D145,333;D171,293;D202,254;D237,218;D276,184;D316,156;D358,132;D402,112;D448,98;D495,88;D544,82;D595,81;D2755,81;D2806,85;D2855,93;D2901,106;D2946,123;D2989,145;D3029,171;D3068,202;D3104,237;D3138,276;D3167,316;D3190,358;D3210,402;D3224,448;D3234,495;D3240,544;D3241,595;D3241,6075;D3237,6126;D3229,6175;D3216,6221;D3199,6266;D3177,6309;D3151,6349;D3120,6388;D3085,6424;D3046,6458;D3006,6487;D2964,6510;D2920,6530;D2874,6544;D2827,6554;D2778,6560;D2727,6561;D567,6561;D516,6557;D467,6549;D421,6536;D376,6519;D333,6497;D293,6471;D254,6440;D218,6405;D184,6366;D156,6326;D132,6284;D112,6240;D98,6194;D88,6147;D82,6098;D81,6047;D81,6027;D81,5987;U3240,0;@;@

6.2 绘制坐标路径

/*** ;:H A L0 ECN U U0,0;U4000,4000;D0,4000;D0,0;D4000,0;D4000,4000;D4000,4000;U4000,0;@;* 上面数据是一个100*100mm的方框，数据分解如下* ;:H A L0 ECN U U0,0;  是整个数据的开头命令* U4000,4000;   ‘U’ 代表抬刀，后面数字是点的绝对坐标，‘;’是命令结束符* D0,4000;   ‘D’ 代表落刀，后面数字是点的绝对坐标，‘;’是命令结束符** @; '@'是整个数据的结束命令，‘;’是命令结束符* <p>* 分辨率是1016/inch,   值4000代表100mm  ,1 inch=25.4 mm*/
public class DrawPLTEditView extends View {private static final String TAG = "DrawPLTView";private Context context;public List<PLTPointGroup> pltPointGroupList = new ArrayList<>();private float offerX, offerY;private int minX, minY;int maxXLength, maxYLength;private float ratioHeight = 1;private Paint paint = new Paint();public DrawPLTEditView(Context context) {this(context, null);this.context = context;}public DrawPLTEditView(Context context, @Nullable AttributeSet attrs) {super(context, attrs);this.context = context;paint.setColor(Color.RED);paint.setAntiAlias(true);paint.setStyle(Paint.Style.FILL);}public void setPltPointGroupList(List<PLTPointGroup> pltPointGroupList) {this.pltPointGroupList = pltPointGroupList;requestLayout();handler.sendEmptyMessageDelayed(1, 1000);}@Overrideprotected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {super.onMeasure(widthMeasureSpec, heightMeasureSpec);int viewWidth = 0, viewHeight = 0;float pltWidth = 0, pltHeight = 0;//图纸坐标宽高if (pltPointGroupList.size() > 0) {maxXLength = pltPointGroupList.get(0).maxXLength;maxYLength = pltPointGroupList.get(0).maxYLength;minX = pltPointGroupList.get(0).minX;minY = pltPointGroupList.get(0).minY;//图纸像素最大宽高 (maxXLength/40f 毫米)pltWidth = getApplyDimension((int) (maxXLength / 40f));pltHeight = getApplyDimension((int) (maxYLength / 40f));if (maxXLength > maxYLength) {//宽大于高viewWidth = ScreenUtils.getScreenWidth(context) - ScreenUtils.dip2px(context, 26) * 2 - ScreenUtils.dip2px(context, 32) * 2;//比例ratioHeight = decimalFloatDouble(viewWidth * 1f / pltWidth);viewHeight = (int) (pltHeight * ratioHeight);ratioHeight = ratioHeight - 0.01f;} else {viewHeight = ScreenUtils.getScreenHeight(context) -ScreenUtils.getStatusBarHeight(context)- ScreenUtils.dip2px(context, 50) * 2 - ScreenUtils.dip2px(context, 32) * 2;//比例ratioHeight = decimalFloatDouble(viewHeight * 1f / pltHeight);viewWidth = (int) (pltWidth * ratioHeight);ratioHeight = ratioHeight - 0.02f;}//解决移动超边缘不可见问题viewWidth = ScreenUtils.getScreenWidth(context);viewHeight = ScreenUtils.getScreenHeight(context)-ScreenUtils.getStatusBarHeight(context);//偏移offerX = (viewWidth - pltWidth * ratioHeight) / 2f;offerY = (viewHeight - pltHeight * ratioHeight) / 2f;Log.e(TAG, "onMeasure: " + ScreenUtils.px2dip(context, viewWidth) + "--" + ScreenUtils.px2dip(context, viewHeight));Log.e(TAG, "onMeasure2: " + ScreenUtils.px2dip(context, pltWidth) + "--" + ScreenUtils.px2dip(context, pltHeight));setMeasuredDimension((int) viewWidth, (int) viewHeight);}}public float decimalFloatDouble(double number) {BigDecimal bigDecimal = BigDecimal.valueOf(number).setScale(2, RoundingMode.DOWN);return bigDecimal.floatValue();}@Overrideprotected void onDraw(Canvas canvas) {super.onDraw(canvas);if (pltPointGroupList.size() > 0) {if(groupIndex>0) {List<PLTPointGroup> pltPointHaveGroupList = pltPointGroupList.subList(0, groupIndex);for (int position = 0; position < pltPointHaveGroupList.size(); position++) {PLTPointGroup pltPointGroup = pltPointHaveGroupList.get(position);for (int i = 0; i < pltPointGroup.pltPointList.size() - 1; i++) {PLTPoint startPltPoint = pltPointGroup.pltPointList.get(i);int startX = startPltPoint.x;int startY = startPltPoint.y;PLTPoint stopPltPoint = pltPointGroup.pltPointList.get(i + 1);int stopX = stopPltPoint.x;int stopY = stopPltPoint.y;float startXX = getApplyDimension((startX - minX) / 40f * ratioHeight);float startYY = getApplyDimension((startY - minY) / 40f * ratioHeight);float stopXX = getApplyDimension((stopX - minX) / 40f * ratioHeight);float stopYY = getApplyDimension((stopY - minY) / 40f * ratioHeight);canvas.drawLine(startXX + offerX,startYY + offerY,stopXX + offerX,stopYY + offerY,paint);}}}PLTPointGroup pltPointGroup = pltPointGroupList.get(groupIndex);for (int i = 0; i < pltPointGroup.pltPointList.size() - 1; i++) {if (i <= childIndex) {PLTPoint startPltPoint = pltPointGroup.pltPointList.get(i);int startX = startPltPoint.x;int startY = startPltPoint.y;PLTPoint stopPltPoint = pltPointGroup.pltPointList.get(i + 1);int stopX = stopPltPoint.x;int stopY = stopPltPoint.y;float startXX = getApplyDimension((startX - minX) / 40f * ratioHeight);float startYY = getApplyDimension((startY - minY) / 40f * ratioHeight);float stopXX = getApplyDimension((stopX - minX) / 40f * ratioHeight);float stopYY = getApplyDimension((stopY - minY) / 40f * ratioHeight);canvas.drawLine(startXX + offerX,startYY + offerY,stopXX + offerX,stopYY + offerY,paint);}}}}int groupIndex = 0;int childIndex = 0;Handler handler = new Handler() {@Overridepublic void handleMessage(@NonNull Message msg) {super.handleMessage(msg);if (msg.what == 1) {childIndex++;if (childIndex >= pltPointGroupList.get(groupIndex).pltPointList.size()) {groupIndex++;childIndex = 0;}if (groupIndex < pltPointGroupList.size()) {invalidate();handler.sendEmptyMessageDelayed(1, 50);}}}};/*** 一次性画完** @param canvas*/private void drawAllPoint(Canvas canvas) {for (int position = 0; position < pltPointGroupList.size(); position++) {PLTPointGroup pltPointGroup = pltPointGroupList.get(position);for (int i = 0; i < pltPointGroup.pltPointList.size() - 1; i++) {PLTPoint startPltPoint = pltPointGroup.pltPointList.get(i);int startX = startPltPoint.x;int startY = startPltPoint.y;PLTPoint stopPltPoint = pltPointGroup.pltPointList.get(i + 1);int stopX = stopPltPoint.x;int stopY = stopPltPoint.y;float startXX = getApplyDimension((startX - minX) / 40f * ratioHeight);float startYY = getApplyDimension((startY - minY) / 40f * ratioHeight);float stopXX = getApplyDimension((stopX - minX) / 40f * ratioHeight);float stopYY = getApplyDimension((stopY - minY) / 40f * ratioHeight);canvas.drawLine(startXX + offerX,startYY + offerY,stopXX + offerX,stopYY + offerY,paint);}}}/*** 像素=毫米x分辨率* dip，像素/英寸单位，1英寸=2.54厘米=25.4毫米* metrics.xdpi * (1.0f/25.4f)  代表分辨率x1.0fx1英寸  就是所需的dip(25.4f毫米级表示1英寸)* (300f / 25.4f) 一英寸上有300像素，一毫米上有 (300f / 25.4f)像素* value 毫米值*/private float getApplyDimension(float value) {return TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_MM, value, context.getResources().getDisplayMetrics());}
}

6.3 效果