java - 使用 Intent 和 ListActivity 单击 ListItem 后如何更改 android 中的屏幕

Question

以下是我正在使用的代码。单击列表项后出现运行时错误。我应该转到下一个屏幕，但出现错误:应用程序意外停止。你能告诉我哪里出了问题吗？

package com.pxr.tutorial.xmltest;

import java.util.ArrayList;
import java.util.HashMap;

import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.NodeList;

import android.app.ListActivity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import android.widget.Toast;

public class Main extends ListActivity {
    /** Called when the activity is first created. */

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

        myrequest();
    }
    void myrequest() 
    {

        setContentView(R.layout.myrequest);

        ArrayList<HashMap<String, String>> mylist = new ArrayList<HashMap<String, String>>();


        String xml = XMLfunctions.getXML("http://10.0.2.2/ss.htm");
        Document doc = XMLfunctions.XMLfromString(xml);

        int numResults = XMLfunctions.numResults(doc);

        if((numResults <= 0)){
            Toast.makeText(Main.this, "Error", Toast.LENGTH_LONG).show();  
            finish();
        }

        NodeList nodes = doc.getElementsByTagName("result");

        for (int i = 0; i < nodes.getLength(); i++) {                           
            HashMap<String, String> map = new HashMap<String, String>();    

            Element e = (Element)nodes.item(i);
            map.put("id", XMLfunctions.getValue(e, "id"));
            map.put("name", XMLfunctions.getValue(e, "id") + "-" + XMLfunctions.getValue(e, "name") + " :");
            mylist.add(map);            
        }       


        ListAdapter adapter = new SimpleAdapter(this, mylist , R.layout.main, 
                        new String[] { "name"}, 
                        new int[] { R.id.item_title });

        setListAdapter(adapter);

        final ListView lv = getListView();
        lv.setTextFilterEnabled(true);  
        lv.setOnItemClickListener(new OnItemClickListener() {
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {              
                @SuppressWarnings("unchecked")
                HashMap<String, String> o = (HashMap<String, String>) lv.getItemAtPosition(position);                   
                Toast.makeText(Main.this, "ID '" + o.get("id") + "' was clicked.", Toast.LENGTH_LONG).show(); 

                Main.this.finish();
                Intent i = new Intent(Main.this, Details.class);
                startActivity(i);

//              details(o.get("id"));

            }
        });

    }

    void details(String id)
    {
        Details dt=new Details();
        dt.det(id);
//      setContentView(R.layout.details);       
    }

}

Details.java 文件是:

package com.pxr.tutorial.xmltest;

import android.app.Activity;
import android.os.Bundle;


    public class Details extends Activity 
    {

        public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.simple);
        }
}

Answer 1

由于您的代码看起来一切正常，我猜您没有权限在 AndroidManifest.xml 中运行 Details Activity 。

添加行

 <activity android:name=".Details"></activity>

您的文件 AndroidManifest.xml 应该可以解决问题!

编辑:此外，行 Main.this.finish(); 也可能导致问题。如果您已经完成了前面的操作，请尝试删除该行。