Android自定义控件绘制基本图形基础入门

package com.example.viewdemo1.view;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Paint.Style;
import android.util.AttributeSet;
import android.view.View;

public class PointView extends View {

 public PointView(Context context, AttributeSet attrs, int defStyleAttr) {
  super(context, attrs, defStyleAttr);
 }

 public PointView(Context context, AttributeSet attrs) {
  super(context, attrs);
 }

 public PointView(Context context) {
  super(context);
 }

 @Override
 protected void onDraw(Canvas canvas) {
  super.onDraw(canvas);
  // 对于画笔
  Paint paint = new Paint();
  // 设置抗锯齿
  paint.setAntiAlias(true);
  // 设置画笔颜色
  paint.setColor(Color.RED);
  // 三种样式
  paint.setStyle(Style.FILL_AND_STROKE);
  paint.setStrokeWidth(5);
  // 阴影
  paint.setShadowLayer(10, 0, 0, Color.CYAN);
  // 点的坐标 x0,y0,x1,y1......
  float[] pts = { 50, 50, 100, 100, 200, 200, 300, 300, 0, 100, 100, 0 };
  canvas.drawPoints(pts, paint);
  // 绘制点的时候，隔着几个点绘制几个，最多不到多少点
  canvas.drawPoints(pts, 1, 6, paint);
 }

}

@Override
 protected void onDraw(Canvas canvas) {
  super.onDraw(canvas);
  // 对于画笔
  Paint paint = new Paint();
  // 设置抗锯齿
  paint.setAntiAlias(true);
  // 设置画笔颜色
  paint.setColor(Color.RED);
  // 三种样式
  paint.setStyle(Style.FILL);
  paint.setStrokeWidth(0.5f);
  // 阴影
  // paint.setShadowLayer(10, 0, 0, Color.CYAN);
  // x0,y0,x1,y1
  float[] pts = { 100, 100, 200, 200, 200, 200, 300, 200, 300, 200, 300,
    400 };
  // 以上是6个点的x,y坐标，两两连成线段
  canvas.drawLines(pts, paint);
  // 画一条线
  canvas.drawLine(0, 0, 100, 100, paint);

  }

//指定圆心坐标，半径就OK
canvas.drawCircle(100, 100, 100, paint);

//设置文字大小
paint.setTextSize(40);
//指定坐标，最好指定文字大小
canvas.drawText("哈", 100, 500, paint);
//将文字设置到指定路径上
Path path = new Path();
paint.setTextSize(50);
path.addCircle(200, 200, 150, Direction.CCW);
canvas.drawTextOnPath("我爱你我的祖国，我爱你我亲爱的姑娘", path, 0, 0, paint);

// 阴影
paint.setShadowLayer(10, 0, 0, Color.CYAN);
// x y 坐标 及半径值
// canvas.drawCircle(100, 100, 50, paint);
canvas.drawRect(50, 50, 300, 300, paint);

 //指定放置圆弧的矩形
 RectF oval=new RectF(10,10,210,210);
 //绘制圆弧-0是指开始度数，270是指结束度数 false是指不连接圆心，paint是画笔
 canvas.drawArc(oval, 0, 270, false, paint);

//指定矩形，指定画笔
canvas.drawOval(oval, paint);