如何在Android中将动态数据从一个活动发送到另一个活动 [英] How to send dynamic data from one activity to another in android
问题描述
我正在开发一个android应用程序，我从mysql数据库中获取数据并将其显示在Listview中.我有数据类别"，例如电信，银行，社交网站等.从MySQL获得的此Category完美地显示在ListView中.现在，当我单击其中任何一个时，它应该移至下一个活动并根据该类别显示数据.假设我单击社交网站"，然后在下一个活动中，数据应该是Google Plus，Instagram，Twitter等，并且此列表将来自数据库并显示在列表视图中.我对此一无所知.. !!!请帮助我...这是我所做的代码.
I am developing an android application where I am getting data from mysql database and displaying that in Listview. I have data "Categories" like Telecom, Banking, Social Sites and so on. This Category getting from mysql, is displaying in ListView perfectly. Now when I click on any one of them, then this should move to next activity and display data according to that category. Suppose I click on Social Sites, then on next activity, the data should be Google Plus, Instagram, Twitter etc and this list will come from Database and display in listview. I am not getting any idea about this how to do that..!!! Please help me...This is my code what I've done.
Welcome.java
Welcome.java
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.util.EntityUtils;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.os.StrictMode;
import android.util.Log;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.ListView;
import android.widget.TextView;
public class Welcome extends Activity
{
TextView text;
//Button b1,b2,b3;
String CompName,CompID;
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_welcome);
StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
StrictMode.setThreadPolicy(policy);
// b1=(Button)findViewById(R.id.dashboard_tab1);
// b1.setOnClickListener(this);
connect();
}
public void connect()
{
String data;
List<String> r = new ArrayList<String>();
ArrayAdapter<String>adapter=new ArrayAdapter<String>(getApplicationContext(), android.R.layout.simple_list_item_1,r);
ListView list=(ListView)findViewById(R.id.list);
try
{
DefaultHttpClient client = new DefaultHttpClient();
HttpGet request = new HttpGet("http://10.0.2.2/database/Retrive.php");
HttpResponse response = client.execute(request);
HttpEntity entity=response.getEntity();
data=EntityUtils.toString(entity);
Log.e("STRING", data);
try
{
JSONArray json=new JSONArray(data);
for(int i=0;i<json.length(); i++)
{
JSONObject obj=json.getJSONObject(i);
CompName=obj.getString("fldCompName");
CompID=obj.getString("fldCompID");
Log.e("STRING", CompName);
Log.e("STRING",CompID);
r.add(CompName);
//r.add(CompID);
list.setAdapter(adapter);
list.setOnItemClickListener(new android.widget.AdapterView.OnItemClickListener()
{
@Override
public void onItemClick(AdapterView<?> parent,View view, int position, long id)
{
Intent i1=new Intent(Welcome.this,Category1.class);
i1.putExtra("CompName", CompName);
startActivity(i1);
}
});
}
}
catch (JSONException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
} catch (ClientProtocolException e) {
Log.d("HTTPCLIENT", e.getLocalizedMessage());
} catch (IOException e) {
Log.d("HTTPCLIENT", e.getLocalizedMessage());
}
}
@Override
public boolean onCreateOptionsMenu(Menu menu)
{
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.welcome, menu);
return true;
}
}
这是我的布局文件... !!!
This is my layout file...!!!
activity_welcome.xml
activity_welcome.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
xmlns:android="http://schemas.android.com/apk/res/android">
<ListView
android:id="@+id/list"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:background="@drawable/bg" >
</ListView>
</LinearLayout>
Retrive.php
Retrive.php
<?php
$host='localhost';
$uname='root';
$pwd='';
$db='database';
$con=mysqli_connect($host,$uname,$pwd) or die("Connection Failed");
mysqli_select_db($con,$db) or die("database selection failed");
$sql=mysqli_query($con,"select fldCompName,fldCompID from tblCompanies where fldStatus='1'");
while($row=mysqli_fetch_assoc($sql))
$output[]=$row;
$a=json_encode($output);
print($a);
mysqli_close();
?>
推荐答案
替换
i1.putExtra("CompName", CompName);
作者
i1.putExtra("CompName", r[position]);
然后在下一个活动中获取此数据，并根据传递的值从DB中获取数据.
Then get this data in the next activity and fetch the data from DB depending on the passed value.
您必须传递用户选择的值.因此，所有值都在适配器r中，您将了解按项目选定位置(onItemClick的第三个参数)选择了哪个用户.因此它应该是r[position].最好在将适配器设置为ListView之前完全填充适配器.因此，从JSON中获取所有数据，将其添加到适配器，然后将该适配器设置为ListView.
You have to pass the value which user has selected. So all your values are in your adapter r and you will get to know which one user has selected by item selected position, which is third parameter of onItemClick. So it should be r[position]. It's better to completely fill the adapter before setting it to ListView. So fetch all the data from JSON, add it to adapter and then set that adapter to ListView.
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