单击按钮时显示ListView

Question

我是android的新手，我的按钮是“myButton”，当我点击此按钮时，我想显示一个从MySQL服务器读取的ListView。我已经完成了如何从MySQL读取并在列表视图中显示的教程，但区别在于我想要一个按钮来激活并在我单击它时显示此列表视图。当我单击myButton时如何打开此列表视图？ / p>

我还有一个Courses课，它只是我的设置和吸气剂。这是我尝试过的代码，并向我展示了一个ListView of Courses：

package usp.ac.fj;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.URL;
import java.net.URLConnection;
import java.util.ArrayList;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import android.os.Bundle;
import android.app.ListActivity;
import android.view.Menu;
import android.widget.ArrayAdapter;

public class AndroidHttpActivity extends ListActivity {

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_android_http);

    String strJsonData = getJsonByHTTP();

 // Convert String JSON data to Java class
    ArrayList<Courses> arrayCourse= parseJsonData(strJsonData);

    //Create an ArrayAdapter which shows the ArrayList data
    this.setListAdapter(new ArrayAdapter<Courses>(this,android.R.layout.simple_list_item_1,arrayCourse));   





}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    getMenuInflater().inflate(R.menu.activity_android_http, menu);
    return true;
}


private String getJsonByHTTP() {

    InputStream is = null;
    try {
        URL url = new URL("http://10.0.2.2/sqlWebService.php");
        URLConnection con = url.openConnection();
        con.setConnectTimeout(10000);
        con.setReadTimeout(10000);
        is = con.getInputStream();

        BufferedReader br = new BufferedReader(
                new InputStreamReader(is));
        StringBuffer sb = new StringBuffer();
        String str;
        while ((str = br.readLine()) != null) {
            sb.append(str);
        }
        return sb.toString();

    } catch (IOException e) {
        e.printStackTrace();
        return "";

    } finally {
        try {
            if (is != null)
                is.close();
        } catch (IOException e2) {
            e2.printStackTrace();
        }
    }
}




private ArrayList<Courses> parseJsonData(String strJson) {
    ArrayList<Courses> Courses = new ArrayList<Courses>();

    try {
        // Generate JSONArray object by JSON String data
        JSONArray arr = new JSONArray(strJson);

        //from the JSONArray, get one element (row) of JSONData
        for (int i = 0; i < arr.length(); i++) {

            //Get JSON Object which is one element of the array
            JSONObject ob = arr.getJSONObject(i);

            Courses course = new Courses();
            //get the value by key, and set to cour class
            course.setCode(ob.optString("code"));

            //save courses class to course array list
            Courses.add(course);
        }
    } catch (JSONException e) {
        e.printStackTrace();
    }
    return Courses;
}

}