package com.yiqiexample.cc;
import java.util.ArrayList;
import java.util.HashMap;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import android.app.Activity;
import android.app.ListActivity;
import android.app.ProgressDialog;
import android.content.Intent;
import android.os.AsyncTask;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.AdapterView;
import android.widget.Button;
import android.widget.CheckBox;
import android.widget.EditText;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.SimpleAdapter;
//import android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toast;
import android.widget.AdapterView.OnItemClickListener;
public class Food extends ListActivity
implements OnClickListener {
// Progress Dialog
private ProgressDialog pDialog;
//testing on Emulator:
private static final String READ_COMMENTS_URL = "http://10.0.2.2/pbda2/foodordered.php";
// my ip add 192.168.43.176
//private CheckBox chkFood, chkDrinks, chkServices;
//private Button btnDisplay, chkClear, deliever, chkClearFood, fooddeliever, drinksdeliever, servicesdeliever, chkClearDrinks, chkClearServices;
//private TextView clearThis,orderdisplay, clearThisFood, foodorderdisplay, drinksorderdisplay, servicesorderdisplay, clearThisDrinks, clearThisServices;
private static final String TAG_SUCCESS = "success";
private static final String TAG_POSTS = "posts";
private static final String TAG_SEATNUMBER = "seatnumber";
private static final String TAG_FOODORDERED = "foodordered";
//it's important to note that the message is both in the parent branch of
//our JSON tree that displays a "Post Available" or a "No Post Available" message,
//and there is also a message for each individual post, listed under the "posts"
//category, that displays what the user typed as their message.
//An array of all of our comments
private JSONArray mComments = null;
//manages all of our comments in a list.
private ArrayList<HashMap<String, String>> mCommentList;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
this.setContentView(R.layout.food);
View v = findViewById(R.id.backmain);
//set event listener
v.setOnClickListener(this);
View z = findViewById(R.id.drinksbtn);
//set event listener
z.setOnClickListener(this);
View x = findViewById(R.id.servicebtn);
//set event listener
x.setOnClickListener(this);
}
@Override
protected void onResume() {
// TODO Auto-generated method stub
super.onResume();
//loading the comments via AsyncTask
new LoadComments().execute();
}
/**
* Retrieves recent post data from the server.
*/
public void updateJSONdata() {
// Instantiate the arraylist to contain all the JSON data.
// we are going to use a bunch of key-value pairs, referring
// to the json element name, and the content, for example,
// message it the tag, and "I'm awesome" as the content..
mCommentList = new ArrayList<HashMap<String, String>>();
// Bro, it's time to power up the J parser
JSONParser jParser = new JSONParser();
// Feed the beast our comments url, and it spits us
//back a JSON object. Boo-yeah Jerome.
JSONObject json = jParser.getJSONFromUrl(READ_COMMENTS_URL);
//when parsing JSON stuff, we should probably
//try to catch any exceptions:
try {
//I know I said we would check if "Posts were Avail." (success==1)
//before we tried to read the individual posts, but I lied...
//mComments will tell us how many "posts" or comments are
//available
mComments = json.getJSONArray(TAG_POSTS);
// looping through all posts according to the json object returned
for (int i = 0; i < mComments.length(); i++) {
JSONObject c = mComments.getJSONObject(i);
//gets the content of each tag
String seatnumber = c.getString(TAG_SEATNUMBER);
String foodordered = c.getString(TAG_FOODORDERED);
// creating new HashMap
HashMap<String, String> map = new HashMap<String, String>();
map.put(TAG_SEATNUMBER, seatnumber);
map.put(TAG_FOODORDERED, foodordered);
// adding HashList to ArrayList
mCommentList.add(map);
//annndddd, our JSON data is up to date same with our array list
}
} catch (JSONException e) {
e.printStackTrace();
}
}
@Override
public void onClick(View arg0) {
if(arg0.getId() == R.id.backmain){
//define a new Intent for the second Activity
Intent intent = new Intent(this,MainActivity.class);
//start the second Activity
this.startActivity(intent);
}
if(arg0.getId() == R.id.drinksbtn){
//define a new Intent for the second Activity
Intent intent = new Intent(this,Drinks.class);
//start the second Activity
this.startActivity(intent);
}
if(arg0.getId() == R.id.servicebtn){
//define a new Intent for the second Activity
Intent intent = new Intent(this,Services.class);
//start the second Activity
this.startActivity(intent);
}
}
/**
* Inserts the parsed data into the listview.
*/
private void updateList() {
// For a ListActivity we need to set the List Adapter, and in order to do
//that, we need to create a ListAdapter. This SimpleAdapter,
//will utilize our updated Hashmapped ArrayList,
//use our single_post xml template for each item in our list,
//and place the appropriate info from the list to the
//correct GUI id. Order is important here.
ListAdapter adapter = new SimpleAdapter(this, mCommentList,
R.layout.single_comment, new String[] { TAG_SEATNUMBER, TAG_FOODORDERED
//TAG_DRINKSORDERED, TAG_SERVICES
}, new int[] { R.id.seatnumber, R.id.orders
//R.id.drinkstv, R.id.servicestv,
});
// I shouldn't have to comment on this one:
setListAdapter(adapter);
// Optional: when the user clicks a list item we
//could do something. However, we will choose
//to do nothing...
ListView lv = getListView();
lv.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
// This method is triggered if an item is click within our
// list. For our example we won't be using this, but
// it is useful to know in real life applications.
//new!
// selected item
String product = ((TextView) view).getText().toString();
// Launching new Activity on selecting single List Item
Intent i = new Intent(getApplicationContext(), SingleListItem.class);
// sending data to new activity
i.putExtra("product", product);
startActivity(i);
//end new lines!!
}
});
}
public class LoadComments extends AsyncTask<Void, Void, Boolean> {
@Override
protected void onPreExecute() {
super.onPreExecute();
pDialog = new ProgressDialog(Food.this);
pDialog.setMessage("Loading orders...");
pDialog.setIndeterminate(false);
pDialog.setCancelable(true);
pDialog.show();
}
@Override
protected Boolean doInBackground(Void... arg0) {
//we will develop this method in version 2
updateJSONdata();
return null;
}
@Override
protected void onPostExecute(Boolean result) {
super.onPostExecute(result);
pDialog.dismiss();
//we will develop this method in version 2
updateList();
}
}
}
single_item.java
package com.yiqiexample.cc;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.widget.TextView;
public class SingleListItem extends Activity{
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
this.setContentView(R.layout.single_list_item_view);
TextView txtProduct = (TextView) findViewById(R.id.product_label);
Intent i = getIntent();
// getting attached intent data
String product = i.getStringExtra("product");
// displaying selected product name
txtProduct.setText(product);
}
}
single_list_item_view.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView android:id="@+id/product_label"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:textSize="25dip"
android:textStyle="bold"
android:padding="10dip"
android:textColor="#ffffff"/>
</LinearLayout>
food.xml
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
xmlns:android1="http://schemas.android.com/apk/res/android"
android1:id="@+id/bg2"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android1:background="#E0FFFF" >
<Button
android1:id="@+id/btnDelete"
android1:layout_width="wrap_content"
android1:layout_height="wrap_content"
android1:layout_alignParentBottom="true"
android1:layout_alignParentRight="true"
android1:text="@string/delete" />
<Button
android:id="@+id/servicebtn"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_marginLeft="358dp"
android:layout_toRightOf="@+id/foodbutton"
android:text="SERVICES" />
<Button
android1:id="@+id/drinksbtn"
android1:layout_width="wrap_content"
android1:layout_height="wrap_content"
android1:layout_alignParentBottom="true"
android1:layout_marginBottom="23dp"
android1:layout_marginRight="24dp"
android1:text="DRINKS ORDERS" />
<LinearLayout
android:id="@+id/top_layover"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true"
android:orientation="horizontal" >
<TextView
android1:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:gravity="center"
android:text="@string/foodtitle"
android:textAppearance="?android:attr/textAppearanceLarge" />
</LinearLayout>
<ListView
android:id="@android:id/list"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_below="@+id/top_layover"
android1:layout_alignBottom="@+id/servicesdelivered"
android:background="#fff"
android:divider="@android:color/transparent"
android:scrollbars="none"
android1:clickable="true" />
<LinearLayout
android:id="@+id/bottom_layover"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignParentLeft="true"
android:orientation="horizontal"
android:weightSum="2" >
<LinearLayout
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:orientation="vertical" >
</LinearLayout>
<LinearLayout
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:orientation="vertical" >
<Button
android1:id="@+id/backmain"
android1:layout_width="wrap_content"
android1:layout_height="wrap_content"
android1:text="@string/backtomain" />
</LinearLayout>
</LinearLayout>
<Button
android1:id="@+id/servicesdelivered"
android1:layout_width="wrap_content"
android1:layout_height="wrap_content"
android1:layout_above="@+id/drinksbtn"
android1:layout_alignParentLeft="true"
android1:layout_marginLeft="111dp"
android1:text="@string/servicesdelivered"
android1:visibility="invisible" />
</RelativeLayout>
当我尝试点击列表视图时， 它似乎是一个错误 -
错误打开跟踪文件：没有这样的文件或目录（2）
我需要帮助才能使listview可以点击，它会打算进入我可以删除特定数据的页面。
答案 0 :(得分：3)
define Listview and Myadapter,DatabaseConnection class globaly
adapter
private ListView listview;
private Myadapter adapter;
private DatabaseConnection databaseconnection;
and in oncreate
listview = (ListView) findViewById(R.id.list);
databaseconnection=new DatabaseConnection(this);
adapter=new Myadapter(this,list); // list means pass record as list and create
custom adapter thats best way
listview.setAdapter(adapter);
listview.setOnItemClickListener(new OnItemClickListener()
{
@Override
public void onItemClick(AdapterView<?> arg0, View arg1,int position, long arg3)
{
//do something here like-
here get the id of record from list using listview position and
detete record from database using dis id
databaseconnection.open(); //create the database object first
deleteRecord(int id); //pass id for delete that record
databaseconnection.close();
}
});
答案 1 :(得分：0)
在您的代码中，您仍然不使用列表视图。首先将其全局定义为
private ListView mList;
然后在onCreate（）内部初始化，如：
mList = (ListView) findViewById(R.id.list);
mList.setAdapter(your_adapter) //this adapter contains the mCommentList arraylist
mList.setOnItemClickListener(new OnItemClickListener()
{
@Override
public void onItemClick(AdapterView<?> arg0, View arg1,int position, long arg3)
{
//do something here
}
});
如果使用适配器类在自定义布局中设置值，那么它很好。 Check this example
谢谢