更改片段大小?

对于android开发而言，这是相当新的东西，我需要知道如何才能实用地更改片段中ListView的大小以覆盖整个屏幕吗? match_parent，fill_parent无法正常工作.

Pretty new to android development, I need to know how I can change the size of my ListView in my fragment pragmatically to cover the entire screen? match_parent, fill_parent didn't work.

我的硬编码值为500dp

I have hard coded values of 500dp

这是我的片段

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <ListView
        android: 
        android:layout_width="500dp"
        android:layout_height="500dp"
        android:divider="@null"
        android:dividerHeight="0dp"
        android:layout_marginTop="0dp">
    </ListView>

</RelativeLayout>

这是JAVA我的片段代码:

and here is JAVA my fragment code:

import android.app.ListFragment;
import android.os.Bundle;
import android.util.DisplayMetrics;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.FrameLayout;
import android.widget.LinearLayout;
import android.widget.ListView;
import android.view.ViewGroup.LayoutParams;
import android.widget.LinearLayout;
import java.util.List;



public class MyFragment extends ListFragment {

    List<data> flowers = new datadata().getdatas();


    public MyFragment() {
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);


       dataArrayAdapter adapter = new dataArrayAdapter(getActivity(),
               R.layout.data_listitem,
               flowers);
       setListAdapter(adapter);


    }

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

        View rootView = inflater.inflate(R.layout.my_fragment, container, false);

        return rootView;
    }

}

这是我的主要活动课

<ScrollView  xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android: 
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:scrollbarStyle="insideOverlay"
    android:scrollbars="none"
    android:fadeScrollbars="true"
    android:fitsSystemWindows="true"
    android:layout_gravity="top"
    >
</ScrollView >

这是我的主要活动Java代码:

and this is my main activity java code:

package mshirvan.example.com.netplex;

import android.app.Activity;
import android.app.AlertDialog;
import android.app.Fragment;
import android.content.Intent;
import android.media.Image;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.AdapterView;
import android.widget.FrameLayout;
import android.widget.ImageView;
import android.widget.ListView;
import android.widget.RelativeLayout;
import android.widget.Toast;
import android.view.View.OnClickListener;

import data.row1;


public class MainActivity extends Activity {

    public static float screenx = 0;
    public static float screeny = 0;
    public static int screenpixelx = 0;
    public static int screenpixely = 0;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        ScreenUtility utility = new ScreenUtility(this);
        screenx = utility.getWidth();
        screeny = utility.getHeight();
        screenpixelx = utility.getPixelWidth();
        screenpixely = utility.getPixelHeight();

        MyFragment frag = new MyFragment();

        getFragmentManager().beginTransaction()
                .add(R.id.myContainer, frag)
                .commit();

    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        if (id == R.id.action_settings) {
            ScreenUtility utility = new ScreenUtility(this);
            String output = "Width: "   utility.getWidth()   ", "  
                    "Height: "   utility.getHeight();

            return true;
        }
        return super.onOptionsItemSelected(item);
    }
}