效果
本文的合集已经编著成书,高级Android开发强化实战,欢迎各位读友的建议和指导。在京东即可购买:https://item.jd.com/12385680.html
AndroidMPAndroidChart是实现图表功能的优秀控件, 可以完成大多数绘制需求. 对于修改第三方库而言, 优秀的架构是继承开发, 而不是把源码拆分出去. MP在显示标记控件(MarkView)时, 会有异常, 导致标志在图表边缘显示不全, 则需要重写控件解决问题.
继承LineChart, 提取高亮位置坐标getHighLightPos
, 重绘标记drawMarkers
.
/**
* 数据中心的图表折线图, 继承MPChart的折线图
* <p>
* Created by wangchenlong on 15/10/13.
*/
public class CYDataLineChart extends LineChart {
@SuppressWarnings("unused")
private static final String TAG = "DEBUG-WCL: " + CYDataLineChart.class.getSimpleName();
// 默认构造器
public CYDataLineChart(Context context) {
super(context);
}
public CYDataLineChart(Context context, AttributeSet attrs) {
super(context, attrs);
}
public CYDataLineChart(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
}
// 获取高亮点坐标
public float[] getHighLightPos(Entry e, Highlight highlight) {
return getMarkerPosition(e, highlight);
}
// 重写这个方法, 修复Bug
@Override
protected void drawMarkers(Canvas canvas) {
// if there is no marker view or drawing marker is disabled
if (mMarkerView == null || !mDrawMarkerViews || !valuesToHighlight())
return;
Rect newRect = canvas.getClipBounds();
newRect.inset(-80, 0); //make the rect larger
canvas.clipRect(newRect, Region.Op.REPLACE);
//noinspection ForLoopReplaceableByForEach
for (int i = 0; i < mIndicesToHighlight.length; i++) {
Highlight highlight = mIndicesToHighlight[i];
int xIndex = highlight.getXIndex();
if (xIndex <= mDeltaX && xIndex <= mDeltaX * mAnimator.getPhaseX()) {
Entry e = mData.getEntryForHighlight(mIndicesToHighlight[i]);
// make sure entry not null
if (e == null || e.getXIndex() != mIndicesToHighlight[i].getXIndex())
continue;
float[] pos = getMarkerPosition(e, highlight);
// Marker偏移
float tmpY = pos[1] - 8 * AppUtils.getPerDp();
Paint paint = new Paint();
paint.setStyle(Paint.Style.FILL);
paint.setAntiAlias(true);
paint.setStrokeWidth(5);
// noinspection deprecation
paint.setColor(getResources().getColor(R.color.chart_circle));
canvas.drawCircle(pos[0], pos[1], 2 * AppUtils.getPerDp(), paint);
// check bounds
if (!mViewPortHandler.isInBounds(pos[0], tmpY))
continue;
mMarkerView.refreshContent(e, highlight);
mMarkerView.measure(MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED),
MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED));
mMarkerView.layout(0, 0, mMarkerView.getMeasuredWidth(),
mMarkerView.getMeasuredHeight());
if (tmpY - mMarkerView.getHeight() <= 0) {
float y = mMarkerView.getHeight() - tmpY;
mMarkerView.draw(canvas, pos[0], tmpY + y);
} else {
mMarkerView.draw(canvas, pos[0], tmpY);
}
}
}
}
}
getMarkerPosition
是LineChart类中的protected方法, 继承类, 使用public方法导出.
float tmpY = pos[1] - 8 * AppUtils.getPerDp();
, 重新计算Y坐标, 偏离原始画布.
但是这样做有一个问题, 在移动MarkView时, 父控件会有残留. 如何解决呢? 办法就是在移动时, 重绘父控件的canvas, 使用invalidate()
函数.
// 设置图表点击事件, 监听高亮位置
mLcChart.setOnChartValueSelectedListener(new OnChartValueSelectedListener() {
@Override
public void onValueSelected(Entry e, int dataSetIndex, Highlight h) {
int index = e.getXIndex();
Log.e(TAG, "index = " + index);
setChartIndex(index);
mCallback.setCurIndex(index);
mIndex = index;
float[] pos = mLcChart.getHighLightPos(e, h);
Log.e(TAG, "x: " + pos[0] + ", y: " + pos[1]);
mLlContainer.invalidate(); // 重绘父控件, 避免残留
}
@Override
public void onNothingSelected() {
// 再次点击时调用这个, 要不非高亮
mLcChart.highlightValue(mIndex, 0);
}
});
// 外部设置图表高亮
private void setChartHighlight(int index) {
if (mLcChart.getData() == null) return;
mMarkerView.setDateText(mMarkers.get(index));
mLcChart.highlightValue(index, 0);
mLlContainer.invalidate(); // 重绘父控件, 避免残留
}
动画在图表控件中, 内部外部都会触发高亮位置.
OK, Enjoy It!
网友评论