Question

我正在尝试在地图上使用数据lat和web服务创建一个标记，但它返回错误空指针。我确实创建了日志数据，并且在日志中成功检索了lat和long数据。请帮忙。提前谢谢。

这是我的KDetail.java

 private PData data;

private static final String TAG = "KDActivity";
private Call<APIBaseResponse> call;
private RestClient.GitApiInterface service;

private Toolbar toolbar;

private SessionManager sessions;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_k_d);
    toolbar = (Toolbar) findViewById(R.id.toolbar);
    this.setSupportActionBar(toolbar);

    sessions = new SessionManager(this);
    Intent i = getIntent();
    data = (PData) i.getSerializableExtra("PDItem");

    txtIdP = (TextView) findViewById(R.id.txtIdP); 
    txtCdt = (EditText) findViewById(R.id.txtCreatedDtm);  

    txtIdP.setText(data.getId_P()); 
    txtCdt.setText(data.getCreatedDtm());      

    final MapFragment mapFragment = (MapFragment) getFragmentManager().findFragmentById(R.id.map);
    mapFragment.getMapAsync(new OnMapReadyCallback() {
        @Override
        public void onMapReady(GoogleMap googleMap) {
            Log.d(TAG, "onMapReady: "); 
            double lata = Double.parseDouble(data.getLatP());
            double lana = Double.parseDouble(data.getLangP());

            googleMap.addMarker(new MarkerOptions()
                    .position(new LatLng(lata, lana))
                    .title("Start") );
        }
    });

}

这是错误：

Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void com.google.android.gms.maps.MapFragment.getMapAsync(com.google.android.gms.maps.OnMapReadyCallback)' on a null object reference
                                                                            at com.kd.kddupe.Activity.KDetail.onCreate(KDetail.java:115)

第115行是：

mapFragment.getMapAsync（new OnMapReadyCallback（）{

这是我的acitivity_k_d.xml：

    <?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:fitsSystemWindows="true"
    android:background="@color/feed_bg">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/view">
        <android.support.design.widget.AppBarLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:theme="@style/AppTheme.AppBarOverlay" >
            <android.support.v7.widget.Toolbar
                android:id="@+id/toolbar"
                android:layout_width="match_parent"
                android:layout_height="?attr/actionBarSize"
                android:background="?attr/colorPrimary"
                app:popupTheme="@style/AppTheme.PopupOverlay"/>
        </android.support.design.widget.AppBarLayout>
    </LinearLayout>


    <ScrollView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_below="@+id/view" >
        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:orientation="vertical"
            android:background="@drawable/bg_parent_rounded_corner"
            android:elevation="6pt"
            android:layout_marginBottom="20dp"
            android:layout_marginLeft="@dimen/feed_item_margin"
            android:layout_marginRight="@dimen/feed_item_margin"
            android:layout_marginTop="@dimen/feed_item_margin"
            android:paddingBottom="@dimen/feed_item_padding_top_bottom"
            android:paddingTop="@dimen/feed_item_padding_top_bottom" >

            <TextView
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:textAppearance="?android:attr/textAppearanceMedium"
                android:text="@string/id_p"
                android:id="@+id/txtIdP"
                android:textColor="@color/colorPrimaryDark"
                android:textStyle="bold"
                android:textSize="18sp"
                android:layout_marginLeft="20dp"
                android:layout_marginRight="20dp"
                android:layout_marginTop="5dp"
                android:layout_marginBottom="20dp"
                android:textAlignment="center"/>

            <View
                android:layout_width="fill_parent"
                android:layout_height="2dp"
                android:background="@color/colorPrimaryDark"
                android:id="@+id/line1" />

            <LinearLayout
                android:layout_width="match_parent"
                android:layout_height="250dp">
                <fragment android:id="@+id/map"
                   android:name="com.google.android.gms.maps.SupportMapFragment"
                    android:layout_width="match_parent"
                    android:layout_height="match_parent"/>
            </LinearLayout>


            <View
                android:layout_width="fill_parent"
                android:layout_height="2dp"
                android:background="@color/colorPrimaryDark"
                android:id="@+id/line2" />

            <LinearLayout
                android:orientation="horizontal"
                android:layout_height="fill_parent"
                android:layout_width="fill_parent"
                android:layout_marginTop="20dp" >
                <LinearLayout
                    android:layout_weight="2"
                    android:layout_height="fill_parent"
                    android:layout_width="0dp"
                    android:orientation="vertical"
                    android:paddingLeft="10dp">
                    <TextView
                        android:layout_width="match_parent"
                        android:layout_height="match_parent"
                        android:text="@string/created"
                        android:textSize="15sp"
                        android:gravity="center_vertical" />
                </LinearLayout>
                <LinearLayout
                    android:layout_weight="4"
                    android:layout_height="fill_parent"
                    android:layout_width="0dp"
                    android:orientation="vertical"
                    android:paddingRight="10dp"
                    android:paddingLeft="5dp">
                    <EditText
                        android:layout_width="match_parent"
                        android:layout_height="wrap_content"
                        android:id="@+id/txtCreatedDtm"
                        android:background="@drawable/bg_parent_rounded_corner"
                        android:hint="@string/yyyy_mm_dd"
                        android:inputType="textMultiLine"
                        android:minHeight="35dp"
                        android:textSize="15sp"
                        android:singleLine="false"
                        android:focusable="false"/>
                </LinearLayout>
            </LinearLayout>

        </LinearLayout>
    </ScrollView>
</RelativeLayout>

Answer 1

检查可能是getSupportFragmentManager()或检查id是map肯定吗？试一试，而不是getFragmentManager

Answer 2

在这里，您可以在XML文件中使用地图片段的支持版本和搜索正常代码的代码。所以要修复它你有两个解决方案

从两个中选择一个

1-将xml处的片段名称更改为

    android:name="com.google.android.gms.maps.MapFragment"

2-将您的java代码{/ 1}更改为MapFragment

MapFragment

2 个答案: