ArcsDemo

package com.example.xfermodesdemo;

import android.app.Activity;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.RectF;
import android.os.Bundle;
import android.view.View;

public class ArcsActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(new SampleView(this));
}

private static class SampleView extends View {
private Paint[] mPaints;
private Paint mFramePaint;// 大图形画笔
private boolean[] mUseCenters;
private RectF[] mOvals;
private RectF mBigOval;
private float mStart;
private float mSweep;
private int mBigIndex;

private static final float SWEEP_INC = 2;
private static final float START_INC = 15;

public SampleView(Context context) {
super(context);

mPaints = new Paint[4];
mUseCenters = new boolean[4];
mOvals = new RectF[4];

//圆1 Paint.Style.FILL
//center false
mPaints[0] = new Paint();
mPaints[0].setAntiAlias(true);// 抗锯齿
mPaints[0].setStyle(Paint.Style.FILL);
mPaints[0].setColor(0x88FF0000);
mUseCenters[0] = false;

//圆2 Paint.Style.FILL
//center true
mPaints[1] = new Paint(mPaints[0]);
mPaints[1].setColor(0x8800FF00);
mUseCenters[1] = true;

//圆3 Paint.Style.STROKE
//center false
mPaints[2] = new Paint(mPaints[0]);
mPaints[2].setStyle(Paint.Style.STROKE);
mPaints[2].setStrokeWidth(4);
mPaints[2].setColor(0x880000FF);
mUseCenters[2] = false;

//圆4 Paint.Style.STROKE
//center true
mPaints[3] = new Paint(mPaints[2]);
mPaints[3].setColor(0x88888888);
mUseCenters[3] = true;

mBigOval = new RectF(40, 10, 280, 250);

mOvals[0] = new RectF(10, 270, 70, 330);
mOvals[1] = new RectF(90, 270, 150, 330);
mOvals[2] = new RectF(170, 270, 230, 330);
mOvals[3] = new RectF(250, 270, 310, 330);

mFramePaint = new Paint();
mFramePaint.setAntiAlias(true);
mFramePaint.setStyle(Paint.Style.STROKE);
mFramePaint.setStrokeWidth(0);
}

private void drawArcs(Canvas canvas, RectF oval, boolean useCenter,
Paint paint) {
canvas.drawRect(oval, mFramePaint);
canvas.drawArc(oval, mStart, mSweep, useCenter, paint);//绘制椭圆的函数
}

@Override
protected void onDraw(Canvas canvas) {
canvas.drawColor(Color.WHITE);

drawArcs(canvas, mBigOval, mUseCenters[mBigIndex],
mPaints[mBigIndex]);

for (int i = 0; i < 4; i++) {
drawArcs(canvas, mOvals[i], mUseCenters[i], mPaints[i]);
}

mSweep += SWEEP_INC;
if (mSweep > 360) {
mSweep -= 360;
mStart += START_INC;
if (mStart >= 360) {
mStart -= 360;
}
mBigIndex = (mBigIndex + 1) % mOvals.length;
}
invalidate();
}
}
}

粉色 Style: Paint.Style.FILL useCenters:false

绿色:Style: Paint.Style.FILL useCenters:true

紫色:Style: Paint.Style.STROKE useCenters:false

灰色:Style: Paint.Style.STROKE useCenters:true