Android自定义View之电池电量显示

package com.kimascend.thermometer.customview;

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

public class DrawView extends View {
private float percent = 1.0f;

public DrawView(Context context, AttributeSet set) {
super(context, set);
}

@Override
// 重写该方法,进行绘图
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
// 电池电量外面的大白框
Paint paint = new Paint();
// 电池电量里面的绿色
Paint paint1 = new Paint();
// 电池头部
Paint paint2 = new Paint();
// 去锯齿
paint.setAntiAlias(true);
paint.setStyle(Paint.Style.FILL);
// 大于百分之30时绿色，否则为红色
if (percent > 0.3f) {
paint.setColor(Color.GREEN);
} else {
paint.setColor(Color.RED);
}

paint1.setAntiAlias(true);
paint1.setStyle(Paint.Style.STROKE);
paint1.setStrokeWidth(4);
paint1.setColor(Color.WHITE);
paint2.setAntiAlias(true);
paint2.setStyle(Paint.Style.FILL);
paint2.setColor(Color.WHITE);
int a = getWidth() - 4;
int b = getHeight() - 4;
// 根据电量百分比画图
float d = a * percent;
RectF re1 = new RectF(4, 4, d - 10, b);
RectF re2 = new RectF(0, 0, a - 6, b + 4);
RectF re3 = new RectF(a - 8, b / 2 - 8, a, b - 6);
// 绘制圆角矩形
canvas.drawRect(re1, paint);
canvas.drawRect(re2, paint1);
canvas.drawRect(re3, paint2);
}

// 每次检测电量都重绘，在检测电量的地方调用
public synchronized void setProgress(int percent) {
this.percent = (float) (percent / 100.0);
postInvalidate();
}
}