写个电量显示的玩意？

这个电量有什么要求呢？

• 充电的时候，会显示动画，除非满血100%
• 插上电源，显示插电状态图标
• 省电模式的时候，显示黄色进度
• 平时显示按电量梯度显示

基本结构

public class BatteryView extends View {

    private int width;
    private int height;
    private int mCurrentLevel;
    private Paint paint;
    private int picWidth;
    private int picHeight;
    private BitmapFactory.Options options;
    private Bitmap chargingPic;
    private BatteryMode mCurrentMode = BatteryMode.NORMAL;

    public BatteryView(Context context) {
        this(context, null);
    }

    public BatteryView(Context context, @Nullable AttributeSet attrs) {
        this(context, attrs, 0);
    }

    public BatteryView(Context context, @Nullable AttributeSet attrs, 
	int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        paint = new Paint();
        paint.setFlags(Paint.ANTI_ALIAS_FLAG);
        options = new BitmapFactory.Options();
        options.inScaled = false;
        Bitmap bitmap = BitmapFactory.decodeResource(getResources(), 
		R.mipmap.battery_level_save_100, options);
        picWidth = bitmap.getWidth();
        picHeight = bitmap.getHeight();
        //加载静态图片列表
        initResource();
        chargingPic = BitmapFactory.decodeResource(getResources(),
		R.mipmap.charge_state, options);
    }

    //充电状态图标变化
    private final int[] chargeBatteryRes = new int[6];
    //普通状态图标
    private final int[] normalBatteryRes = new int[7];
    //省电模式图标
    private final int[] saveModeBatteryRes = new int[7];

    @Override
    protected void onSizeChanged(int w, int h, int oldw, int oldh) {
        super.onSizeChanged(w, h, oldw, oldh);
        width = w;
        height = h;
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        ICLogger.d("picWidth == > " + picWidth + " picHeight == > " + picHeight);
        setMeasuredDimension(picWidth, picHeight);
    }

    private int currentDrawPic = -1;

    public enum BatteryMode {
        SAVE, NORMAL
    }

    public void updateMode(BatteryMode mode) {
        this.mCurrentMode = mode;
    }




    private void initResource() {
        //充电变化的图标
        chargeBatteryRes[0] = R.mipmap.battery_chage_0;
        chargeBatteryRes[1] = R.mipmap.battery_level_20;
        chargeBatteryRes[2] = R.mipmap.battery_level_40;
        chargeBatteryRes[3] = R.mipmap.battery_level_60;
        chargeBatteryRes[4] = R.mipmap.battery_level_80;
        chargeBatteryRes[5] = R.mipmap.battery_level_100;
        //普通状态图标
        normalBatteryRes[0] = R.mipmap.battery_level_0;
        normalBatteryRes[1] = R.mipmap.battery_level_10;
        normalBatteryRes[2] = R.mipmap.battery_level_save_20;
        normalBatteryRes[3] = R.mipmap.battery_level_40;
        normalBatteryRes[4] = R.mipmap.battery_level_60;
        normalBatteryRes[5] = R.mipmap.battery_level_80;
        normalBatteryRes[6] = R.mipmap.battery_level_100;
        //省电模式状态图标
        saveModeBatteryRes[0] = R.mipmap.battery_level_0;
        saveModeBatteryRes[1] = R.mipmap.battery_level_10;
        saveModeBatteryRes[2] = R.mipmap.battery_level_save_20;
        saveModeBatteryRes[3] = R.mipmap.battery_level_save_40;
        saveModeBatteryRes[4] = R.mipmap.battery_level_save_60;
        saveModeBatteryRes[5] = R.mipmap.battery_level_save_80;
        saveModeBatteryRes[6] = R.mipmap.battery_level_save_100;
    }
}

详情请看代码注释了

对外暴露的功能

• charging(boolean isCharging) 修改当前的状态，是否为充电状态--->控制充电状态图标的显示，以及动画播放控制
• updateCurrentLev更新当前电量
• updateMode(BatteryMode mode) 更新当前模式为省电模式还是普通模式，根据模式显示不同的套图

完整代码

public class BatteryView extends View {

    private int width;
    private int height;
    private int mCurrentLevel;
    private Paint paint;
    private int picWidth;
    private int picHeight;
    private BitmapFactory.Options options;
    private Bitmap chargingPic;
    private BatteryMode mCurrentMode = BatteryMode.NORMAL;

    public BatteryView(Context context) {
        this(context, null);
    }

    public BatteryView(Context context, @Nullable AttributeSet attrs) {
        this(context, attrs, 0);
    }

    public BatteryView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        paint = new Paint();
        paint.setFlags(Paint.ANTI_ALIAS_FLAG);
        options = new BitmapFactory.Options();
        options.inScaled = false;
        Bitmap bitmap = BitmapFactory.decodeResource(getResources(), R.mipmap.battery_level_save_100, options);
        picWidth = bitmap.getWidth();
        picHeight = bitmap.getHeight();
        //加载静态图片列表
        initResource();
        chargingPic = BitmapFactory.decodeResource(getResources(), R.mipmap.charge_state, options);
    }

    //充电状态图标变化
    private final int[] chargeBatteryRes = new int[6];
    //普通状态图标
    private final int[] normalBatteryRes = new int[7];
    //省电模式图标
    private final int[] saveModeBatteryRes = new int[7];

    @Override
    protected void onSizeChanged(int w, int h, int oldw, int oldh) {
        super.onSizeChanged(w, h, oldw, oldh);
        width = w;
        height = h;
    }


    private boolean isCharging = false;

    public void charging(boolean isCharging) {
        //充电状态，播放动画，显示充电图标
        this.isCharging = isCharging;
        //充电，并且不是100%的电量
        if (isCharging && mCurrentLevel != 100) {
            post(task);
        } else {
            //显示当前电量图标
            showCurrentLev();
        }
    }

    //更新当前电量图标
    public void updateCurrentLev(int level) {
        if (level > 100 || level < 0) {
            throw new IllegalArgumentException("level range must in [0，100]");
        }
        this.mCurrentLevel = level;
        showCurrentLev();
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        ICLogger.d("picWidth == > " + picWidth + " picHeight == > " + picHeight);
        setMeasuredDimension(picWidth, picHeight);
    }

    private int currentDrawPic = -1;

    public enum BatteryMode {
        SAVE, NORMAL
    }

    public void updateMode(BatteryMode mode) {
        this.mCurrentMode = mode;
    }

    private void showCurrentLev() {
        loopIndex = 0;
        //停掉所有的动画
        removeCallbacks(task);
        //对当前电量进行转换
        int index;
        if (mCurrentLevel < 5) {
            index = 0;
        } else if (mCurrentLevel < 20) {
            index = 1;
        } else if (mCurrentLevel < 40) {
            index = 2;
        } else if (mCurrentLevel < 60) {
            index = 3;
        } else if (mCurrentLevel < 80) {
            index = 4;
        } else if (mCurrentLevel < 99) {
            index = 5;
        } else {
            index = 6;
        }
        ICLogger.d("current index == > " + index);
        //判断是不是省电模式
        if (mCurrentMode == BatteryMode.NORMAL) {
            currentDrawPic = normalBatteryRes[index];
        } else {
            currentDrawPic = saveModeBatteryRes[index];
        }
        invalidate();
    }

    @Override
    public void draw(Canvas canvas) {
        super.draw(canvas);
        if (currentDrawPic == -1) {
            return;
        }
        //绘制内容
        //电量图标
        Bitmap bitmap = BitmapFactory.decodeResource(getResources(), currentDrawPic, options);
        canvas.drawBitmap(bitmap, 0, 0, paint);
        //是否要绘制充电中的图标
        if (isCharging) {
            int left = width / 2 - chargingPic.getWidth() / 2;
            canvas.drawBitmap(chargingPic, left, 0, paint);
        }
    }

    private int loopIndex = 0;

    private final Runnable task = new Runnable() {
        @Override
        public void run() {
            if (loopIndex >= chargeBatteryRes.length) {
                loopIndex = 0;
            }
            //循环读取内容
            currentDrawPic = chargeBatteryRes[loopIndex];
            invalidate();
            loopIndex++;
            postDelayed(this, 1000);
        }
    };


    private void initResource() {
        //充电变化的图标
        chargeBatteryRes[0] = R.mipmap.battery_chage_0;
        chargeBatteryRes[1] = R.mipmap.battery_level_20;
        chargeBatteryRes[2] = R.mipmap.battery_level_40;
        chargeBatteryRes[3] = R.mipmap.battery_level_60;
        chargeBatteryRes[4] = R.mipmap.battery_level_80;
        chargeBatteryRes[5] = R.mipmap.battery_level_100;
        //普通状态图标
        normalBatteryRes[0] = R.mipmap.battery_level_0;
        normalBatteryRes[1] = R.mipmap.battery_level_10;
        normalBatteryRes[2] = R.mipmap.battery_level_save_20;
        normalBatteryRes[3] = R.mipmap.battery_level_40;
        normalBatteryRes[4] = R.mipmap.battery_level_60;
        normalBatteryRes[5] = R.mipmap.battery_level_80;
        normalBatteryRes[6] = R.mipmap.battery_level_100;
        //省电模式状态图标
        saveModeBatteryRes[0] = R.mipmap.battery_level_0;
        saveModeBatteryRes[1] = R.mipmap.battery_level_10;
        saveModeBatteryRes[2] = R.mipmap.battery_level_save_20;
        saveModeBatteryRes[3] = R.mipmap.battery_level_save_40;
        saveModeBatteryRes[4] = R.mipmap.battery_level_save_60;
        saveModeBatteryRes[5] = R.mipmap.battery_level_save_80;
        saveModeBatteryRes[6] = R.mipmap.battery_level_save_100;
    }
}