最近在開發(fā)時遇到這樣一種需求两残，為一些特殊點(diǎn)顯示標(biāo)簽忌栅，類似默認(rèn)顯示多個markview。如下圖（demo）：

image

在網(wǎng)上并沒有相關(guān)資料，在此做下記錄分享

下面上代碼:

首先創(chuàng)建一個類繼承LineChart,重寫init()方法：

@Override
protected void init() {
    super.init();
    //獲取屏幕寬度,上圖最邊上標(biāo)簽跳仿，會根據(jù)屏幕寬度適配
    WindowManager wm = (WindowManager) getContext().getSystemService(Context.WINDOW_SERVICE);
    DisplayMetrics metrics = new DisplayMetrics();
    wm.getDefaultDisplay().getMetrics(metrics);
    mRenderer = new HbFundLineChartRenderer(this, mAnimator, mViewPortHandler, metrics.widthPixels);
}

接下來是主要內(nèi)容,也就是自己實(shí)現(xiàn)的LineChartRenderer即渲染器,用來畫點(diǎn)捐晶、線等.
首先是一些變量,分別是標(biāo)記控件的寬高邊距等,這里寫的是一些根據(jù)我們需求來的默認(rèn)值：

private int mWidth;//屏幕寬度,在構(gòu)造方法中傳進(jìn)來賦值
private float hViewLength = Utils.convertDpToPixel(30f);//vie寬30dp
private float vViewLength = Utils.convertDpToPixel(20f);//view高20dp
private float viewRect= Utils.convertDpToPixel(4f);//矩形高低差

然后,在LineChartRenderer中有一個drawValues,它是主要負(fù)責(zé)根據(jù)值來畫點(diǎn)的,我們要做的就是在super()之后加上我們自己的東西：

@Override
public void drawValues(Canvas c) {
    super.drawValues(c);
    if (isShowLabel) {
        LineDataSet dataSetByIndex = (LineDataSet) mChart.getLineData().getDataSetByIndex(0);
        Transformer trans = mChart.getTransformer(dataSetByIndex.getAxisDependency());
        Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG);//抗鋸齒畫筆
        paint.setTextSize(Utils.convertDpToPixel(textSixe));//設(shè)置字體大小

        //畫首中尾三個label
        float[] firstFloat = getFloat(dataSetByIndex.getValues(), 0);//根據(jù)數(shù)據(jù)集獲取點(diǎn)
        drawPointLabel(trans, paint, c, firstFloat);
        float[] middleFloat = getFloat(dataSetByIndex.getValues(), (dataSetByIndex.getValues().size() - 1) / 2);
        drawPointLabel(trans, paint, c, middleFloat);
        float[] endFloat = getFloat(dataSetByIndex.getValues(), dataSetByIndex.getValues().size() - 1);
        drawPointLabel(trans, paint, c, endFloat);
    }
}

首先獲取點(diǎn)的數(shù)據(jù)集,然后得到Transformer,它可以根據(jù)點(diǎn)數(shù)據(jù)集里的某一點(diǎn)來得到這個點(diǎn)在屏幕中的位置
然后分別傳入transformer惑灵、畫筆、畫布對象佩憾、點(diǎn),進(jìn)行繪制：

private void drawPointLabel(Transformer trans, Paint paint, Canvas c, float[] floatPosition) {
    MPPointD maxPoint = trans.getPixelForValues(floatPosition[0], floatPosition[1]);
    float highX = (float) maxPoint.x;
    float highY = (float) maxPoint.y;
    TextView view = (TextView) LayoutInflater.from(mContext).inflate(R.layout.mark_view, null, false);
    if (highX > mWidth - mWidth / 4) {//標(biāo)識朝左
        view.setBackgroundResource(R.mipmap.sm_lable_bg_buy_r);
        Bitmap bitmap = createBitmap(view, (int) hViewLength, (int) vViewLength);
        c.drawBitmap(bitmap, (int) (highX - hViewLength), (int) (highY - vViewLength - viewRect), paint);
    } else if (highX < mWidth / 4) {//標(biāo)識朝右
        view.setBackgroundResource(R.mipmap.sm_lable_bg_buy_l);
        Bitmap bitmap = createBitmap(view, (int) hViewLength, (int) vViewLength);
        c.drawBitmap(bitmap, (int) (highX), (int) (highY - vViewLength - viewRect), paint);
    } else {//標(biāo)識居中
        view.setBackgroundResource(R.mipmap.sm_lable_bg_buy_c);
        Bitmap bitmap = createBitmap(view, (int) hViewLength, (int) vViewLength);
        c.drawBitmap(bitmap, (int) (highX - hViewLength / 2), (int) (highY - vViewLength - viewRect), paint);
    }
}

此處鸯屿，我們隨意定義幾個點(diǎn)，可以根據(jù)實(shí)際需求進(jìn)行設(shè)置：

private float[] getFloat(List<Entry> lists, int index) {
    float[] maxEntry = new float[2];
    maxEntry[0] = lists.get(index).getX();
    maxEntry[1] = lists.get(index).getY();
    return maxEntry;
}

view轉(zhuǎn)bitmap方法如下：

private Bitmap createBitmap(View v, int width, int height) {
    //測量使得view指定大小
    int measuredWidth = View.MeasureSpec.makeMeasureSpec(width, View.MeasureSpec.EXACTLY);
    int measuredHeight = View.MeasureSpec.makeMeasureSpec(height, View.MeasureSpec.EXACTLY);
    v.measure(measuredWidth, measuredHeight);
    //調(diào)用layout方法布局后谅辣，可以得到view的尺寸大小
    v.layout(0, 0, v.getMeasuredWidth(), v.getMeasuredHeight());
    Bitmap bmp = Bitmap.createBitmap(v.getWidth(), v.getHeight(), Bitmap.Config.ARGB_8888);
    Canvas c = new Canvas(bmp);
    v.draw(c);
    return bmp;
}

最后附上原文鏈接及代碼