Android自定义View实现自动转圈效果

本文实例为大家分享了Android实现自动转圈效果展示的具体代码，供大家参考，具体内容如下

在values文件夹下创建attrs.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
<declare-styleable name="MyPb">
 <attr name="circle_color" format="color" />
 <attr name="circle_radius" format="dimension" /><!-- 尺寸 -->
 <attr name="circle_x" format="dimension" />
 <attr name="circle_y" format="dimension" />
</declare-styleable>
</resources>

写一个类继承view

package widget;

import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.RectF;
import android.support.annotation.Nullable;
import android.util.AttributeSet;
import android.view.View;

import com.bwie.zdycircle.R;

import java.util.Timer;
import java.util.TimerTask;

/**
* Created by Administrator on 2017/12/7.
*/

public class MyPb extends View {

private float radius, cx, cy;
private Paint paint;
private float sweepAngle;// 旋转角度

public MyPb(Context context) {
 super(context, null);
}

public MyPb(Context context, @Nullable AttributeSet attrs) {
 super(context, attrs);
 // 获取自定义的属性
 TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.MyPb);

// 获取颜色
 int color = a.getColor(R.styleable.MyPb_circle_color, Color.BLACK);// 获取不到给默认值
 radius = a.getDimension(R.styleable.MyPb_circle_radius, 20);
 cx = a.getDimension(R.styleable.MyPb_circle_x, 100);
 cy = a.getDimension(R.styleable.MyPb_circle_y, 100);

// 需要回收
 a.recycle();

paint = new Paint();
 paint.setAntiAlias(true);// 抗锯齿
 paint.setColor(color);
 paint.setStyle(Paint.Style.STROKE);// 空心

Timer timer = new Timer();
 timer.schedule(new TimerTask() {
  @Override
  public void run() {
   if (sweepAngle > 360) {
    return;
   }
   sweepAngle += 1;
   postInvalidate();
  }
 }, 1000, 20);// 每隔20毫秒执行一次

}

@Override
protected void onDraw(Canvas canvas) {
 paint.setColor(Color.BLUE);
 paint.setStrokeWidth(10);
 canvas.drawCircle(cx, cy, radius, paint);// 画圆
 paint.setStrokeWidth(20);// 粗细
 // 画运动的轨迹
 paint.setColor(Color.RED);
 // 上下左右与圆重合，左边为圆心的横坐标减去半径，上边为纵坐标减去半径,以此类推
 RectF rectF = new RectF(cx - radius, cy - radius, cx + radius, cy + radius);
 // 起始角度，旋转角度，第三个属性为是否填充，画笔
 canvas.drawArc(rectF, -90, sweepAngle, false, paint);

// 绘制文字
 int progress = (int) (sweepAngle / 360f * 100);
 paint.setTextSize(50);
 paint.setStrokeWidth(0);
 paint.setColor(Color.BLACK);
 canvas.drawText(progress + "％", cx - 20, cy, paint);
}
}

在主页面布局中引入自定义view类

<?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"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.bwie.zdycircle.MainActivity">

<widget.MyPb
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 app:circle_color="#0000ff"
 app:circle_radius="70dp"
 app:circle_x="200dp"
 app:circle_y="200dp" />

</LinearLayout>

来源：https://blog.csdn.net/cyq_0927/article/details/78748111