从Android向php传递参数

在我的Android中：

    String cat_id = getIntent().getExtras().getString("category_id");

    ArrayList<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>();
    nameValuePairs.add(new BasicNameValuePair("cat_id", cat_id));

    try {
        HttpClient httpclient = new DefaultHttpClient();
        HttpPost httppost = new HttpPost(
                "http://www.---.com/items.php");
        httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
        HttpResponse response = httpclient.execute(httppost);
        HttpEntity entity = response.getEntity();
        is = entity.getContent();
    } catch (Exception e) {
        Log.e("log_tag", "Error in http connection" + e.toString());
    }

String cat_id=getIntent（）.getExtras（）.getString（“category_id”）；
ArrayList nameValuePairs=新的ArrayList（）；
添加（新的BasicNameValuePair（“cat_id”，cat_id））；
试一试{
HttpClient HttpClient=新的DefaultHttpClient（）；
HttpPost HttpPost=新的HttpPost(
"http://www.---.com/items.php");
setEntity（新的UrlEncodedFormEntity（nameValuePairs））；
HttpResponse response=httpclient.execute（httppost）；
HttpEntity=response.getEntity（）；
is=entity.getContent（）；
}捕获（例外e）{
e（“Log_标记”，“http连接错误”+e.toString（））；
}

在我的PHP中：

// editing out DB connections which have been verified to work


 <?php
$sql=mysql_query("SELECT * FROM items WHERE cat_id = '".$_REQUEST['cat_id']."'");
while($row=mysql_fetch_assoc($sql))
    $output[]=$row;
print(json_encode($output));
mysql_close();
 ?>

//编辑出已验证有效的DB连接
这条线不应该吗

$sql=mysql_query("SELECT * FROM items WHERE cat_id = '".$_REQUEST['cat_id']."'");

是

i、 e.$\请求$\发送邮件

我建议使用Firefox的Firebug插件，并跟踪post发送到服务器的确切形式。
我知道是什么，没有回答是谁的错

这个问题是在Java传给PHP之前开始的。这是一个传递到相关Java活动中的包。我犯了一个简单的错误，使用了一个不正确的原语，这反过来导致通过bundle传入null

空值沿着路径继续，并到达PHP部分。所以上面显示的代码实际上是正确的
 CustomList.java:->

import android.app.Activity;
import android.content.Context;
import android.graphics.Typeface;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ImageView;
import android.widget.TextView;

public class CustomList extends ArrayAdapter<String>{

private final Activity context;
private final String[] web;
private final String[] imageId;
Context ct;
public CustomList(Activity context,
String[] web, String[] imageId) {
super(context, R.layout.list_single, web);
this.context = context;
this.web = web;
this.imageId = imageId;
ct=context;

}
@Override
public View getView(int position, View view, ViewGroup parent) {
LayoutInflater inflater = context.getLayoutInflater();
View rowView= inflater.inflate(R.layout.list_single, null, true);
TextView txtTitle = (TextView) rowView.findViewById(R.id.txt);
TextView txtval=(TextView)rowView.findViewById(R.id.val);

//Typeface tf=Typeface.createFromAsset(ct.getAssets(), "saral.ttf");
//Typeface tf=Typeface.createFromAsset(ct.getAssets(), "shrutib.ttf");
//txtTitle.setTypeface(tf);
//txtTitle.setText(web[position]);
//txtval.setTypeface(tf);
txtval.setText(imageId[position]);
//ImageView imageView = (ImageView) rowView.findViewById(R.id.img);

//imageView.setImageResource(imageId[position]);
return rowView;
}
}

导入android.app.Activity；
导入android.content.Context；
导入android.graphics.Typeface；
导入android.view.LayoutInflater；
导入android.view.view；
导入android.view.ViewGroup；
导入android.widget.ArrayAdapter；
导入android.widget.ImageView；
导入android.widget.TextView；
公共类CustomList扩展了ArrayAdapter{
私人最终活动背景；
私有最终字符串[]web；
私有最终字符串[]imageId；
背景ct；
公共自定义列表（活动上下文，
字符串[]web，字符串[]imageId）{
super（上下文、R.layout.list_single、web）；
this.context=上下文；
this.web=web；
this.imageId=imageId；
ct=上下文；
}
@凌驾
公共视图getView（内部位置、视图视图、视图组父视图）{
LayoutInflater充气器=上下文。getLayoutInflater（）；
视图行视图=充气机。充气（R.layout.list_single，null，true）；
TextView txtTitle=（TextView）rowView.findViewById（R.id.txt）；
TextView txtval=（TextView）rowView.findViewById（R.id.val）；
//Typeface tf=Typeface.createFromAsset（ct.getAssets（），“saral.ttf”）；
//Typeface tf=Typeface.createFromAsset（ct.getAssets（），“shrutib.ttf”）；
//txtTitle.setTypeface（tf）；
//setxt（web[位置]）；
//txtval.setTypeface（tf）；
txtval.setText（imageId[位置]）；
//ImageView ImageView=（ImageView）rowView.findViewById（R.id.img）；
//setImageResource（imageId[位置]）；
返回行视图；
}
}

MainActivity.java:->

package learn2crack.customlistview;

import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import android.net.ParseException;
import android.os.Bundle;
import android.os.StrictMode;
import android.util.Log;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.Toast;
import android.app.Activity;
import android.content.Intent;


public class MainActivity extends Activity {
    ListView list;

    String result = null;
    InputStream is = null;
    StringBuilder sb = null;

    String[] web=null;
    String[] imageId = null;

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


        StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
        StrictMode.setThreadPolicy(policy); 

        // http post
try {
HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost("link of php page");
// httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
HttpResponse response = httpclient.execute(httppost);
HttpEntity entity = response.getEntity();
is = entity.getContent();
} catch (Exception e) {
Log.e("log_tag", "Error in http connection" + e.toString());
                }

                // convert response to string
try {
BufferedReader reader = new BufferedReader(new InputStreamReader(is, "iso-8859-1"), 8);
sb = new StringBuilder();
sb.append(reader.readLine() + "\n");
String line = "0";
while ((line = reader.readLine()) != null) {
    sb.append(line + "\n");
    }
is.close();
result = sb.toString();
} catch (Exception e) {
    Log.e("log_tag", "Error converting result " + e.toString());
}   

// paring data
//JSONObject jArray;
JSONArray jArray;
    try {
    jArray = new JSONArray(result);
    JSONObject json_data = null;
    web = new String[jArray.length()];
    imageId=new String[jArray.length()];
    for (int i = 0; i < jArray.length(); i++) {
json_data = jArray.getJSONObject(i);
web[i] = json_data.getString("category_id");
imageId[i] = json_data.getString("category_name");
}
} catch (JSONException e1) {
Toast.makeText(getBaseContext(), "No City Found", Toast.LENGTH_LONG).show();
} catch (ParseException e1) {
e1.printStackTrace();
}
CustomList adapter = new CustomList(MainActivity.this, web, imageId);
list=(ListView)findViewById(R.id.list);
list.setAdapter(adapter);
list.setOnItemClickListener(new AdapterView.OnItemClickListener() {

                    @Override
     public void onItemClick(AdapterView<?> parent, View view,int position, long id) {
Intent newint=new Intent(getApplicationContext(), subcatcls.class);
newint.putExtra("cat_id",web[+ position]);
                        startActivity(newint);
                    }
                });
    }
}

package learn2crack.customlistview；
导入java.io.BufferedReader；
导入java.io.InputStream；
导入java.io.InputStreamReader；
导入org.apache.http.HttpEntity；
导入org.apache.http.HttpResponse；
导入org.apache.http.client.HttpClient；
导入org.apache.http.client.methods.HttpPost；
导入org.apache.http.impl.client.DefaultHttpClient；
导入org.json.JSONArray；
导入org.json.JSONException；
导入org.json.JSONObject；
导入android.net.ParseException；
导入android.os.Bundle；
导入android.os.StrictMode；
导入android.util.Log；
导入android.view.view；
导入android.widget.AdapterView；
导入android.widget.ArrayAdapter；
导入android.widget.ListView；
导入android.widget.Toast；
导入android.app.Activity；
导入android.content.Intent；
公共类MainActivity扩展了活动{
列表视图列表；
字符串结果=null；
InputStream=null；
StringBuilder sb=null；
字符串[]web=null；
字符串[]imageId=null；
@凌驾
创建时受保护的void（Bundle savedInstanceState）{
super.onCreate（savedInstanceState）；
setContentView（R.layout.activity_main）；
StrictMode.ThreadPolicy policy=新建StrictMode.ThreadPolicy.Builder（）.permitAll（）.build（）；
StrictMode.setThreadPolicy（策略）；
//http post
试一试{
HttpClient HttpClient=新的DefaultHttpClient（）；
HttpPost HttpPost=新的HttpPost（“php页面链接”）；
//setEntity（新的UrlEncodedFormEntity（nameValuePairs））；
HttpResponse response=httpclient.execute（httppost）；
HttpEntity=response.getEntity（）；
is=entity.getContent（）；
}捕获（例外e）{
e（“Log_标记”，“http连接错误”+e.toString（））；
}
//将响应转换为字符串
试一试{
BufferedReader reader=新的BufferedReader（新的InputStreamReader（is，“iso-8859-1”），8；
sb=新的StringBuilder（）；
sb.append（reader.readLine（）+“\n”）；
字符串行=“0”；
而（（line=reader.readLine（））！=null）{
sb.追加（第+行“\n”）；
}
is.close（）；
结果=sb.toString（）；
}捕获（例外e）{
Log.e（“Log_标记”，“错误转换结果”+e.toString（））；
}   
//配对数据
//JSONObject jArray；
杰索纳雷·贾雷；
试一试{
jArray=新的JSONArray（结果）；
JSONObject json_data=null；
web=新字符串[jArray.length（）]；
imageId=新字符串[jArray.length（）]；
for（int i=0；ipackage learn2crack.customlistview;

import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import android.net.ParseException;
import android.os.Bundle;
import android.os.StrictMode;
import android.util.Log;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.Toast;
import android.app.Activity;
import android.content.Intent;


public class MainActivity extends Activity {
    ListView list;

    String result = null;
    InputStream is = null;
    StringBuilder sb = null;

    String[] web=null;
    String[] imageId = null;

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


        StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
        StrictMode.setThreadPolicy(policy); 

        // http post
try {
HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost("link of php page");
// httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
HttpResponse response = httpclient.execute(httppost);
HttpEntity entity = response.getEntity();
is = entity.getContent();
} catch (Exception e) {
Log.e("log_tag", "Error in http connection" + e.toString());
                }

                // convert response to string
try {
BufferedReader reader = new BufferedReader(new InputStreamReader(is, "iso-8859-1"), 8);
sb = new StringBuilder();
sb.append(reader.readLine() + "\n");
String line = "0";
while ((line = reader.readLine()) != null) {
    sb.append(line + "\n");
    }
is.close();
result = sb.toString();
} catch (Exception e) {
    Log.e("log_tag", "Error converting result " + e.toString());
}   

// paring data
//JSONObject jArray;
JSONArray jArray;
    try {
    jArray = new JSONArray(result);
    JSONObject json_data = null;
    web = new String[jArray.length()];
    imageId=new String[jArray.length()];
    for (int i = 0; i < jArray.length(); i++) {
json_data = jArray.getJSONObject(i);
web[i] = json_data.getString("category_id");
imageId[i] = json_data.getString("category_name");
}
} catch (JSONException e1) {
Toast.makeText(getBaseContext(), "No City Found", Toast.LENGTH_LONG).show();
} catch (ParseException e1) {
e1.printStackTrace();
}
CustomList adapter = new CustomList(MainActivity.this, web, imageId);
list=(ListView)findViewById(R.id.list);
list.setAdapter(adapter);
list.setOnItemClickListener(new AdapterView.OnItemClickListener() {

                    @Override
     public void onItemClick(AdapterView<?> parent, View view,int position, long id) {
Intent newint=new Intent(getApplicationContext(), subcatcls.class);
newint.putExtra("cat_id",web[+ position]);
                        startActivity(newint);
                    }
                });
    }
}