java 点击时显示值 [MPAndroidChart]
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Show value when tapped [MPAndroidChart]
提问by Rod_Algonquin
I`ve been looking for a way to enable the MPAndroidChart to only display the value(label) of data point when clicked. But It seems that I could not find it online even in the documentation.
我一直在寻找一种方法，使 MPAndroidChart 仅在单击时显示数据点的值（标签）。但似乎即使在文档中我也无法在网上找到它。
I used the line chartand what I want is to only display the label of the certain point when clicked.
我使用了line chart，我想要的是仅在单击时显示特定点的标签。
回答by rafaelasguerra
1- Enable touchin the chart
1-在图表中启用触摸
chart.setTouchEnabled(true);
2 - Create MarkerView
2 -创建 MarkerView
public class CustomMarkerView extends MarkerView {
private TextView tvContent;
public CustomMarkerView (Context context, int layoutResource) {
super(context, layoutResource);
// this markerview only displays a textview
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) {
tvContent.setText("" + e.getVal()); // set the entry-value as the display text
}
@Override
public int getXOffset() {
// this will center the marker-view horizontally
return -(getWidth() / 2);
}
@Override
public int getYOffset() {
// this will cause the marker-view to be above the selected value
return -getHeight();
}
}
3 - Create the tvContent view
3 - 创建tvContent 视图
<?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="40dp"
android:background="@drawable/markerImage" >
<TextView
android:id="@+id/tvContent"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:layout_marginTop="7dp"
android:layout_marginLeft="5dp"
android:layout_marginRight="5dp"
android:text=""
android:textSize="12dp"
android:textColor="@android:color/white"
android:ellipsize="end"
android:singleLine="true"
android:textAppearance="?android:attr/textAppearanceSmall" />
</RelativeLayout>
4.Set the view Marker in the chart
4.在图表中设置view Marker
CustomMarkerView mv = new CustomMarkerView (Context, R.layout.custom_marker_view_layout);
chart.setMarkerView(mv);
回答by Andrea Scalabrini
Use IMarker Interface(MarkerView has been deprecated since release 3.0.0)
使用IMarker 接口（MarkerView 自 3.0.0 版以来已被弃用）
1. Create a new class that implements the IMarker interface
1.新建一个实现IMarker接口的类
public class YourMarkerView extends MarkerView {
private TextView tvContent;
public MyMarkerView(Context context, int layoutResource) {
super(context, layoutResource);
// find your layout components
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) {
tvContent.setText("" + e.getY());
// this will perform necessary layouting
super.refreshContent(e, highlight);
}
private MPPointF mOffset;
@Override
public MPPointF getOffset() {
if(mOffset == null) {
// center the marker horizontally and vertically
mOffset = new MPPointF(-(getWidth() / 2), -getHeight());
}
return mOffset;
}}
2. set your marker to the chart
2. 将标记设置为图表
IMarker marker = new YourMarkerView();
chart.setMarker(marker);
Reference: https://github.com/PhilJay/MPAndroidChart/wiki/IMarker-Interface
参考：https: //github.com/PhilJay/MPAndroidChart/wiki/IMarker-Interface
