MPAndroidChart自定义MarkerView

效果图

代码

自定义MarkerView

public class CustomMPLineChartMarkerView extends MarkerView {
    private final int DEFAULT_INDICATOR_COLOR = 0xffFD9138;//指示器默认的颜色
    private final int ARROW_HEIGHT = dp2px(5); // 箭头的高度
    private final int ARROW_WIDTH = dp2px(10); // 箭头的宽度
    private final float ARROW_OFFSET = dp2px(2);//箭头偏移量
    private final float BG_CORNER = dp2px(2);//背景圆角
    private final TextView tvContent;//文本
    private Bitmap bitmapForDot;//选中点图片
    private int bitmapWidth;//点宽
    private int bitmapHeight;//点高

    public CustomMPLineChartMarkerView(Context context) {
        super(context, R.layout.layout_for_custom_marker_view);
        tvContent = findViewById(R.id.tvContent);
        //图片自行替换
        bitmapForDot = BitmapFactory.decodeResource(getResources(), R.drawable.icon_linechart_dot_check);
        bitmapWidth = bitmapForDot.getWidth();
        bitmapHeight = bitmapForDot.getHeight();
    }

    @Override
    public void refreshContent(Entry e, Highlight highlight) {
        if (e instanceof CandleEntry) {
            CandleEntry ce = (CandleEntry) e;
            tvContent.setText(Utils.formatNumber(ce.getHigh(), 0, true));
        } else {
            tvContent.setText(Utils.formatNumber(e.getY(), 0, true));
        }

        super.refreshContent(e, highlight);
    }

    @Override
    public void draw(Canvas canvas, float posX, float posY) {
        Chart chart = getChartView();
        if (chart == null) {
            super.draw(canvas, posX, posY);
            return;
        }

        //指示器背景画笔
        Paint bgPaint = new Paint();
        bgPaint.setStyle(Paint.Style.FILL);
        bgPaint.setAntiAlias(true);
        bgPaint.setColor(DEFAULT_INDICATOR_COLOR);
        //剪头画笔
        Paint arrowPaint = new Paint();
        arrowPaint.setStyle(Paint.Style.FILL);
        arrowPaint.setAntiAlias(true);
        arrowPaint.setColor(DEFAULT_INDICATOR_COLOR);

        float width = getWidth();
        float height = getHeight();

        int saveId = canvas.save();
        //移动画布到点并绘制点
        canvas.translate(posX, posY);
        canvas.drawBitmap(bitmapForDot, -bitmapWidth / 2f , -bitmapHeight / 2f ,null);

        //画指示器
        Path path = new Path();
        RectF bRectF;
        if (posY < height + ARROW_HEIGHT + ARROW_OFFSET + bitmapHeight / 2f) {//处理超过上边界
            //移动画布并绘制三角形和背景
            canvas.translate(0, height + ARROW_HEIGHT + ARROW_OFFSET + bitmapHeight / 2f);
            path.moveTo(0, -(height + ARROW_HEIGHT));
            path.lineTo(ARROW_WIDTH / 2f, -(height - BG_CORNER));
            path.lineTo(- ARROW_WIDTH / 2f, -(height - BG_CORNER));
            path.lineTo(0, -(height + ARROW_HEIGHT));

            bRectF=new RectF(-width / 2, -height, width / 2, 0);

            canvas.drawPath(path, arrowPaint);
            canvas.drawRoundRect(bRectF, BG_CORNER, BG_CORNER, bgPaint);
            canvas.translate(-width / 2f, -height);
        } else {//没有超过上边界
            //移动画布并绘制三角形和背景
            canvas.translate(0, -height - ARROW_HEIGHT - ARROW_OFFSET - bitmapHeight / 2f);
            path.moveTo(0, height + ARROW_HEIGHT);
            path.lineTo(ARROW_WIDTH / 2f, height - BG_CORNER);
            path.lineTo(- ARROW_WIDTH / 2f, height - BG_CORNER);
            path.lineTo(0, height + ARROW_HEIGHT);

            bRectF=new RectF(-width / 2, 0, width / 2, height);

            canvas.drawPath(path, arrowPaint);
            canvas.drawRoundRect(bRectF, BG_CORNER, BG_CORNER, bgPaint);
            canvas.translate(-width / 2f, 0);
        }
        draw(canvas);
        canvas.restoreToCount(saveId);
    }

    private int dp2px(int dpValues) {
        return (int) TypedValue.applyDimension(
                TypedValue.COMPLEX_UNIT_DIP, dpValues,
                getResources().getDisplayMetrics());
    }
}

layout_for_custom_marker_view.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content">

    <TextView
        android:id="@+id/tvContent"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textColor="@android:color/white"/>
</RelativeLayout>

设置MarkerView

CustomMPLineChartMarkerView mv = new CustomMPLineChartMarkerView(this);
mv.setChartView(lineChart);
chart.setMarker(mv);