将RelativeLayout用作自定义InfoWindow时的NullPointerException

本文介绍了将RelativeLayout用作自定义InfoWindow时的NullPointerException的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！

问题描述

我试图为我的标记使用 RelativeLayout 作为自定义 InfoWindow ，但是我得到 NullPointerException 每次调用 showInfoWindow （通过点击 Marker 或以编程方式）。我使用的是Google Maps Android API v2。

例外情况：

  FATAL EXCEPTION：main 
 android.widget.RelativeLayout.onMeasure（RelativeLayout.java:465）$ b $ java.lang.NullPointerException 
 $ b在android.view.View.measure（View.java:15172）
在maps.ayi（未知源）
在maps.aya（未知源）
在maps.awa（未知源）
在maps.a.bd.a（未知源）
在maps.y.bw.b（未知源）
在maps.y.bw.a（未知源） 
 at maps.a.dh.a（未知来源）
 at maps.anc（未知来源）
 at maps.a.dw.a（未知来源）
 at地图.a.bd.c（未知来源）
 at maps.a.dq.onSingleTapConfirmed（未知来源）
 at maps.evonSingleTapConfirmed（未知来源）
 at maps.ejhandleMessage（未知来源）
 ...

我的代码

* cus tom_infowindow.xml *

 <？xml version =1.0encoding =utf-8 >？; 
< RelativeLayout xmlns：android =http://schemas.android.com/apk/res/android
 android：layout_width =wrap_content
 android：layout_height =wrap_content 
 android：padding =10dip> 
 
< ImageView 
 android：id =@ + id / icon
 android：layout_width =wrap_content
 android：layout_height =wrap_content
 android：layout_alignParentRight =true
 android：paddingLeft =10dip
 android：paddingRight =10dip
 android：paddingTop =5dip
 android：src = @ drawable / icon/> 
 
 TextView 
 android：id =@ + id / title
 android：layout_width =match_parent
 android：layout_height =wrap_content
 android：layout_toLeftOf =@ id / icon
 android：ellipsize =end
 android：paddingLeft =10dip
 android：paddingRight =10dip
 android ：singleLine =true/> 
 
 TextView 
 android：id =@ + id / snippet
 android：layout_width =match_parent
 android：layout_height =wrap_content
 android：layout_below =@ id / title
 android：layout_toLeftOf =@ id / icon
 android：ellipsize =end
 android：paddingBottom =10dip
 android：paddingLeft =10dip
 android：paddingRight =10dip
 android：singleLine =true/> 
 
< / RelativeLayout>

CustomInfoWindowAdapter.java

  public class CustomInfoWindowAdapter implements InfoWindowAdapter {
 $ b $ private view View layout; 
私人LayoutInflater inflater; 
 
 public CustomInfoWindowAdapter（Context context）{
 inflater = LayoutInflater.from（context）; 
} 
 
 @Override 
 public View getInfoContents（Marker marker）{
 return null; 
} 
 
 @Override 
 public View getInfoWindow（Marker marker）{
 ViewHolder持有者; 
 
 if（layout == null）{
 layout = inflater.inflate（R.layout.custom_infowindow，null）; 
 
 holder = new ViewHolder（）; 
 holder.title =（TextView）layout.findViewById（R.id.title）; 
 holder.snippet =（TextView）layout.findViewById（R.id.snippet）; 
 
 layout.setTag（持有人）; 
} else {
 holder =（ViewHolder）layout.getTag（）; 
} 
 
 holder.title.setText（marker.getTitle（））; 
 holder.snippet.setText（marker.getSnippet（））; 
 
返回布局; 
} 
 
 static class ViewHolder {
 TextView title; 
 TextView snippet; 
} 
 
}

有趣的是，如果我使用 LinearLayout 相反，它可以正常工作，但如果可能的话，我宁愿只使用一个 ViewGroup 。当然，我想知道 onMeasure 抛出一个 NullPointerException 。

编辑：另外，在 FrameLayout 或<$ c $内包装 RelativeLayout c> LinearLayout 可以工作。将它包装在另一个 RelativeLayout 当然不会。

解决方案

我有这个问题，并能够通过添加

  view.setLayoutParams（new ViewGroup.LayoutParams（desiredWidth，desiredHeight）） ;

到InfoWindowAdapter.getInfoWindow返回之前的视图

I'm trying to use a RelativeLayout as custom InfoWindow for my markers, but a I get a NullPointerException every time showInfoWindow is called (via tapping on a Marker or programmatically). I'm using Google Maps Android API v2.

Exception:

FATAL EXCEPTION: main
java.lang.NullPointerException
    at android.widget.RelativeLayout.onMeasure(RelativeLayout.java:465)
    at android.view.View.measure(View.java:15172)
    at maps.a.y.i(Unknown Source)
    at maps.a.y.a(Unknown Source)
    at maps.a.w.a(Unknown Source)
    at maps.a.bd.a(Unknown Source)
    at maps.y.bw.b(Unknown Source)
    at maps.y.bw.a(Unknown Source)
    at maps.a.dh.a(Unknown Source)
    at maps.a.n.c(Unknown Source)
    at maps.a.dw.a(Unknown Source)
    at maps.a.bd.c(Unknown Source)
    at maps.a.dq.onSingleTapConfirmed(Unknown Source)
    at maps.e.v.onSingleTapConfirmed(Unknown Source)
    at maps.e.j.handleMessage(Unknown Source)
    ...

My code:

*custom_infowindow.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"
    android:padding="10dip" >

    <ImageView
        android:id="@+id/icon"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentRight="true"
        android:paddingLeft="10dip"
        android:paddingRight="10dip"
        android:paddingTop="5dip"
        android:src="@drawable/icon" />

    <TextView
        android:id="@+id/title"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_toLeftOf="@id/icon"
        android:ellipsize="end"
        android:paddingLeft="10dip"
        android:paddingRight="10dip"
        android:singleLine="true" />

    <TextView
        android:id="@+id/snippet"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_below="@id/title"
        android:layout_toLeftOf="@id/icon"
        android:ellipsize="end"
        android:paddingBottom="10dip"
        android:paddingLeft="10dip"
        android:paddingRight="10dip"
        android:singleLine="true" />

</RelativeLayout>

CustomInfoWindowAdapter.java

public class CustomInfoWindowAdapter implements InfoWindowAdapter {

    private View layout;
    private LayoutInflater inflater;

    public CustomInfoWindowAdapter(Context context) {
        inflater = LayoutInflater.from(context);
    }

    @Override
    public View getInfoContents(Marker marker) {
        return null;
    }

    @Override
    public View getInfoWindow(Marker marker) {
        ViewHolder holder;

        if (layout == null) {
            layout = inflater.inflate(R.layout.custom_infowindow, null);

            holder = new ViewHolder();
            holder.title = (TextView) layout.findViewById(R.id.title);
            holder.snippet = (TextView) layout.findViewById(R.id.snippet);

            layout.setTag(holder);
        } else {
            holder = (ViewHolder) layout.getTag();
        }

        holder.title.setText(marker.getTitle());
        holder.snippet.setText(marker.getSnippet());

        return layout;
    }

    static class ViewHolder {
        TextView title;
        TextView snippet;
    }

}

Funny thing is that if I use LinearLayout instead it works just fine, but I'd rather use only one ViewGroup if possible. And of course I would like to know what happens with that onMeasure throwing a NullPointerException.

EDIT: Also, wrapping the RelativeLayout inside a FrameLayout or a LinearLayout will work. Wrapping it inside another RelativeLayout won't, of course.

解决方案

I had this problem and was able to fix it by adding

view.setLayoutParams(new ViewGroup.LayoutParams(desiredWidth,desiredHeight));

to the view before returning it from InfoWindowAdapter.getInfoWindow

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