Java RelativeLayout应用程序中的Android片段崩溃

我正在将一个应用程序转换到android上，在碎片方面遇到了一些问题

当我没有

RelativeLayout

而只是

Fragment

时，它工作得很好，但是随着布局（rel或线性）的引入，它崩溃了。我正试图在地图的顶部添加一些按钮，最好是重叠的，而不是在它自己的空间中

event_layout.xml：

<RelativeLayout android:layout_width="fill_parent"
            android:layout_height="fill_parent"
            xmlns:android="http://schemas.android.com/apk/res/android"
            android:id="@+id/relativeLayout">
    <fragment
       android:id="@+id/the_map"
       android:layout_width="match_parent"
       android:layout_height="match_parent"
       class="com.google.android.gms.maps.SupportMapFragment"/>
    <Button android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:layout_alignParentBottom="true"
            android:text="Start service"/>
</RelativeLayout>

EventFragment.java：

public class EventFragment extends FragmentActivity {

    private int userIcon, foodIcon, drinkIcon, shopIcon, otherIcon;
    private GoogleMap theMap;
    private LocationManager locMan;
    private Marker userMarker;

    public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {

        View V = inflater.inflate(R.layout.event_layout, container, false);

        // now run code below the inflate

        if(theMap==null){
            //map not instantiated yet
            theMap = ((SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.the_map)).getMap();

        }

        //theMap.setMapType(GoogleMap.MAP_TYPE_HYBRID);

        //updatePlaces();

        theMap.setMyLocationEnabled(true);

        theMap.moveCamera( CameraUpdateFactory.newLatLngZoom(new LatLng(54.328337, -2.743149) ,14) );

        JSONArray arrayResultFromURL;

        // store the result of the data into the variable
        arrayResultFromURL = getJSONfromURL("http://www.websitewebsitestr.org/json.php?f=all&type=dateAndTime");
        try{
            //Log.d("array_len", String.format("%d", arrayResultFromURL.length()));

            for(int i=0;i<arrayResultFromURL.length();i++){
                JSONObject json_data = arrayResultFromURL.getJSONObject(i);

                // assign attributes from the JSON string to local variables
                String id =json_data.getString("id");
                String title =json_data.getString("title");
                String strap; // define this for the try catch

                // this try catch is in case the client does not 
                // put a strap in, title is mandatory
                try{
                    strap =json_data.getString("strap");
                }catch(Exception e){
                    strap = "";
                }

                Double lat = (double) 0;
                Double lon = (double) 0;

                // if the lat and long have not been entered then set them to 0
                // otherwise an exception is thrown, and if it is lat and long will
                // become 0, putting them down south.
                try{
                    lat = (double) json_data.getDouble("lat");
                }catch(Exception e){
                    lat = (double) 0;
                }

                try{
                    lon = (double) json_data.getDouble("long");
                }catch(Exception e){
                    lon = (double) 0;
                }

                theMap.addMarker(new MarkerOptions()
                .position(new LatLng(lat, lon))
                .title(title)
                .snippet(strap));
            }
        }catch (Exception e){
            Log.e("log_tag", "error in array: " + e.toString());
        }


        //Log.d("log_tag", "result: " + res);
        //Log.d("log_tag", "point debug!");

        //Log.d("myApp", res.toString());

        userIcon = R.drawable.common_signin_btn_icon_dark;
        /*foodIcon = R.drawable.red_point;
        drinkIcon = R.drawable.blue_point;
        shopIcon = R.drawable.green_point;
        otherIcon = R.drawable.purple_point;*/

        //return V;
        return inflater.inflate(R.layout.event_layout, container, false);
    }

    public static JSONArray getJSONfromURL(String url){

        //initialize
        InputStream is = null;   
        String result = "";   
        JSONArray jArray = null;

        //http post
        try {

            HttpClient httpclient = new DefaultHttpClient();   
            HttpPost httppost = new HttpPost(url);    
            HttpResponse response = httpclient.execute(httppost);
            HttpEntity entity = response.getEntity();

            is = entity.getContent();    

        } catch (Exception e) {
            Log.e("log_tag", "Error in http connection "+e.toString());   
        }
        //convert response to string

        try {

            BufferedReader reader = new BufferedReader(new InputStreamReader(is,"iso-8859-1"),8);  
            StringBuilder sb = new StringBuilder();   
            String line = null;

            while ((line = reader.readLine()) != null) {   
                sb.append(line);
            }

            is.close();
            result=sb.toString();

        } catch (Exception e) {    
            Log.e("log_tag", "Error converting result "+e.toString());
        }
        //try parse the string to a JSON object

        try {
            //Log.d("log_tag", "jresult: " + result + "finish");
            jArray = new JSONArray(result);

            //Log.e("log_tag", "result: " + jArray.toString());

        } catch (JSONException e) {
            Log.e("log_tag", "Error parsing data "+e.toString());
        }

        return jArray;
    }


     public boolean onMarkerClick(Marker marker) {
         Log.d("Debug_log", "clicked!!");
         return true;
     }

}

我曾尝试使用其他stackoverflow帖子中建议的框架，但应用程序要么崩溃，要么被窃听，我无法解决它。在过去的一周里，我在安卓系统中学到了很多东西，我很兴奋将来能学到更多

试试这段代码

map = ((SupportMapFragment) getSupportFragmentManager()
        .findFragmentById(R.id.map)).getMap();

还有进口

import android.support.v4.app.FragmentActivity;

在你这么做之前 右键单击项目->属性->构建路径->java构建路径->库。。然后单击addexternaljars

去

\android SDK\extras\android\support\v4

---

然后选择android-support-v4.jar

嘿，谢谢你的评论，我已经添加了v4-support jar并按照步骤操作，我在

getSupportFragmentManager

上收到一个错误，说它对于类型EventFragmentextends FragmentActivity是未定义的。。扩展此功能并查看谢谢，这已解决了错误。应用程序仍在崩溃，但会显示

ClassCastException

作为错误，您可以发布日志吗？您的概念是错误的…创建选项卡主机活动并将所有活动放在其中

map = ((SupportMapFragment) getSupportFragmentManager()
        .findFragmentById(R.id.map)).getMap();

import android.support.v4.app.FragmentActivity;