Android使用Kotlin自定义View的方法教程

package top.greendami.mykotlinapp
import android.content.Context
import android.graphics.*
import android.util.AttributeSet
import android.view.View
/**
 * Created by GreendaMi on 2017/4/10.
 */
class PPCircle : View {
 var mDatas = ArrayList()
 var mColors = ArrayList(4)
 var mPaint: Paint = Paint()
 constructor(mContext: Context) : super(mContext) {
 val cOntext= mContext
 }
 constructor(mContext: Context, mAttributeSet: AttributeSet) : super(mContext, mAttributeSet) {
 initPaint()
 val cOntext= mContext
 }
 fun initPaint() {
 mPaint.isAntiAlias = true
 mPaint.style = Paint.Style.FILL_AND_STROKE
 mPaint.color = 0xff44b391.toInt()
 }
 //长宽一致
 override fun onMeasure(widthMeasureSpec: Int, heightMeasureSpec: Int) {
 super.onMeasure(widthMeasureSpec, heightMeasureSpec)
 val widthSpecSize = View.MeasureSpec.getSize(widthMeasureSpec)
 val heightSpecSize = View.MeasureSpec.getSize(heightMeasureSpec)
 val mLayoutSize = Math.min(widthSpecSize, heightSpecSize)
 setMeasuredDimension(mLayoutSize, mLayoutSize)
 }
 /**
 * 设置数据
 */
 fun setData(data: ArrayList, colors: ArrayList) {
 mDatas = data
 mColors = colors
 invalidate()
 }
 override fun onDraw(canvas: Canvas&＃63;) {
 super.onDraw(canvas)
 if (mDatas.size == 0) {
  return
 }
 //切掉圆心
 var mPath = Path()
 mPath.addCircle(width / 2f, height / 2f, width / 2f * 0.4f,Path.Direction.CW)
 mPath.close()
 canvas&＃63;.clipPath(mPath, Region.Op.XOR)
 var total = 0f
 //此处亮点
 mDatas.forEach { total += it }
 var rf = RectF(0f, 0f, width.toFloat(), height.toFloat())
 var startAngle = -90f//起点
 var i = 0
 mDatas.forEach {
  mPaint.color = mColors[i]
  var sweepAngle = it * 360 / total
  canvas&＃63;.drawArc(rf, startAngle, sweepAngle, true, mPaint)
  startAngle += sweepAngle
  i++
 }
 }
}

package top.greendami.mykotlinapp
import android.os.Bundle
import android.support.v7.app.AppCompatActivity
import kotlinx.android.synthetic.main.activity_main2.*
class Main2Activity : AppCompatActivity() {
 override fun onCreate(savedInstanceState: Bundle&＃63;) {
  super.onCreate(savedInstanceState)
  setContentView(R.layout.activity_main2)
  var mDatas = ArrayList()
  mDatas.add(1f)
  mDatas.add(2f)
  mDatas.add(4f)
  mDatas.add(2f)
  var mColors = ArrayList()
  mColors.add(0xff83ccd2.toInt())
  mColors.add(0xffc0e1ce.toInt())
  mColors.add(0xfffac55e.toInt())
  mColors.add(0xffef805f.toInt())
  ppCircle.setData(mDatas,mColors)
 }
}

<&＃63;xml version="1.0" encoding="utf-8"&＃63;>

 

package com.allrun.arsmartelevatorformanager.widget;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.Path;
import android.graphics.RectF;
import android.graphics.Region;
import android.support.annotation.Nullable;
import android.util.AttributeSet;
import android.view.View;
import java.util.ArrayList;
import java.util.List;
/**
 * Created by GreendaMi on 2017/4/11.
 */
public class PPCircle extends View {
 Context mContext;
 List mData = new ArrayList();//数据
 List mColors = new ArrayList();//数据对应的颜色
 Paint mPaint = new Paint();
 public PPCircle(Context context) {
  super(context);
 }
 public PPCircle(Context context, @Nullable AttributeSet attrs) {
  super(context, attrs);
  mCOntext= context;
  initPaint();
 }
 private void initPaint() {
  mPaint.setAntiAlias(true);
  mPaint.setStyle(Paint.Style.FILL_AND_STROKE);
 }
 @Override
 protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
  super.onMeasure(widthMeasureSpec, heightMeasureSpec);
  int widthSpecSize = View.MeasureSpec.getSize(widthMeasureSpec);
  int heightSpecSize = View.MeasureSpec.getSize(heightMeasureSpec);
  int mLayoutSize = Math.min(widthSpecSize, heightSpecSize);
  setMeasuredDimension(mLayoutSize, mLayoutSize);
 }
 public void setData(List mData, List mColors) {
  this.mData = mData;
  this.mColors = mColors;
 }
 @Override
 protected void onDraw(Canvas canvas) {
  super.onDraw(canvas);
  if (mData.size() == 0) {
   return;
  }
  //切掉圆心
  Path mPath =new Path();
  mPath.addCircle(getWidth()/2,getWidth()/2,getWidth()/2* 0.4f ,Path.Direction.CW);
  canvas.clipPath(mPath, Region.Op.XOR);

  float total = 0;
  for(float temp : mData){
   total = total + temp;
  }
  RectF rf = new RectF(0f, 0f, getWidth(), getHeight());
  float startAngle = -90f;//起点
  int i = 0;
  for(float temp : mData){
   mPaint.setColor(mColors.get(i));
   float sweepAngle = temp * 360 / total;
   canvas.drawArc(rf, startAngle, sweepAngle, true, mPaint);
   startAngle += sweepAngle;
   i++;
  }
 }
}