MPAndroidChart项目实战——MarkerView显示问题解决

Demo补充中（UpDating）：https://github.com/JinBoy23520/MPAndroidChartDemoByJin

本文出自：http://blog.csdn.net/dt235201314/article/details/56841839

一丶慨述

在运用三方开源库时常会遇到不满足需求的情况，比喻MPAndroidChart的MarkerView显示问题。

二丶解决后效果图展示

说明，未修改前MarkerView会出现显示不全问题（弹框位置在图表外不显示）

三丶关键代码

思路：当弹框显示位置大于布局位置，做判断重写MarkerView类

重写MarkerView类：

public class NewMarkerView extends MarkerView {

    private TextView tvContent;
    private CallBack mCallBack;

    public NewMarkerView(Context context, int layoutResource) {
        super(context, layoutResource);

        tvContent = (TextView) findViewById(R.id.tvContent);
    }

    // callbacks everytime the MarkerView is redrawn, can be used to update the
    // content (user-interface)
    @Override
    public void refreshContent(Entry e, Highlight highlight) {

        String values;
        if (e instanceof CandleEntry) {
            CandleEntry ce = (CandleEntry) e;
            values = "" + Utils.formatNumber(ce.getHigh(), 0, true);
        } else {
            values = "" + Utils.formatNumber(e.getY(), 0, true);
        }

        if (mCallBack != null) {
            mCallBack.onCallBack(e.getX(), values);
        }
        super.refreshContent(e, highlight);
    }

    @Override
    public MPPointF getOffset() {
        tvContent.setBackgroundResource(R.drawable.chart_popu);
        return new MPPointF(0, -getHeight());
    }

    @Override
    public MPPointF getOffsetRight() {
        tvContent.setBackgroundResource(R.drawable.chart_popu_right);
        return new MPPointF(-getWidth(), -getHeight());
    }

    public void setCallBack (CallBack callBack) {
        this.mCallBack = callBack;
    }
    public interface CallBack {
        void onCallBack(float x, String value);
    }

    public TextView getTvContent() {
        return tvContent;
    }
}

这里方法NewMarkerView（）用来绑定布局

方法refreshContent（）用来获取最点击坐标点的值

下面的方法则是设置弹框布局显示位置

MarkerView类添加判断回调markview的方法，直接上修改后代码

public class MarkerView extends RelativeLayout implements IMarker {

    private MPPointF mOffset = new MPPointF();
    private MPPointF mOffset2 = new MPPointF();
    private WeakReference mWeakChart;

    /**
     * Constructor. Sets up the MarkerView with a custom layout resource.
     *
     * @param context
     * @param layoutResource the layout resource to use for the MarkerView
     */
    public MarkerView(Context context, int layoutResource) {
        super(context);
        setupLayoutResource(layoutResource);
    }

    /**
     * Sets the layout resource for a custom MarkerView.
     *
     * @param layoutResource
     */
    private void setupLayoutResource(int layoutResource) {

        View inflated = LayoutInflater.from(getContext()).inflate(layoutResource, this);

        inflated.setLayoutParams(new LayoutParams(RelativeLayout.LayoutParams.WRAP_CONTENT, RelativeLayout.LayoutParams.WRAP_CONTENT));
        inflated.measure(MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED));

        // measure(getWidth(), getHeight());
        inflated.layout(0, 0, inflated.getMeasuredWidth(), inflated.getMeasuredHeight());
    }

    public void setOffset(MPPointF offset) {
        mOffset = offset;

        if (mOffset == null) {
            mOffset = new MPPointF();
        }
    }

    public void setOffset(float offsetX, float offsetY) {
        mOffset.x = offsetX;
        mOffset.y = offsetY;
    }

    @Override
    public MPPointF getOffset() {
        return mOffset;
    }

    public MPPointF getOffsetRight() {
        return mOffset;
    }

    public void setChartView(Chart chart) {
        mWeakChart = new WeakReference<>(chart);
    }

    public Chart getChartView() {
        return mWeakChart == null ? null : mWeakChart.get();
    }

    @Override
    public MPPointF getOffsetForDrawingAtPoint(float posX, float posY) {

        Chart chart = getChartView();
        MPPointF offset = getOffset();
        float width = getWidth();
        float height = getHeight();

        mOffset2.x = offset.x;

        if (chart != null && posX + width + mOffset2.x > chart.getWidth()) {
            offset = getOffsetRight();
            mOffset2.x = offset.x;
        }

        mOffset2.y = offset.y;

        if (posX + mOffset2.x < 0) {
            mOffset2.x = - posX;
        } /*else if (chart != null && posX + width + mOffset2.x > chart.getWidth()) {
            mOffset2.x = chart.getWidth() - posX - width;
        }*/

        if (posY + mOffset2.y < 0) {
            mOffset2.y = - posY;
        } else if (chart != null && posY + height + mOffset2.y > chart.getHeight()) {
            mOffset2.y = chart.getHeight() - posY - height;
        }

        return mOffset2;
    }

    @Override
    public void refreshContent(Entry e, Highlight highlight) {

        measure(MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED),
                MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED));
        layout(0, 0, getMeasuredWidth(), getMeasuredHeight());

    }

    @Override
    public void draw(Canvas canvas, float posX, float posY) {

        MPPointF offset = getOffsetForDrawingAtPoint(posX, posY);

        int saveId = canvas.save();
        // translate to the correct position and draw
        canvas.translate(posX + offset.x, posY + offset.y);
        draw(canvas);
        canvas.restoreToCount(saveId);
    }
}

主要修改位置：

详细用法参照博客：

 MPAndroidChart项目实战（二）——双平滑曲线（双折线图）和MarkView实现