从Android将参数传递给php

Question

在我的安卓系统中：

    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());
    }

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();
 ?>

所以我的问题是它什么都不返回（在 JSON 结果部分——Toast 说“未找到任何项目”）。我的代码是否正确，我将参数从 Android 传递到 PHP 的方式？

Answer 1

这行不应该

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

成为

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

即$_REQUEST 到 $_POST？

我建议使用 Firefox 的 Firebug 插件，并跟踪发送到服务器的确切表单。

Answer 2

我知道是什么，不回答不是任何人的错。

问题开始于之前 Java 传递给 PHP。这是一个传递到相关 Java Activity 的包。我有一个简单的错误，涉及使用不正确的原语，这反过来导致通过捆绑传递空值。

null 继续沿着路径向下并落在 PHP 部分。所以上面显示的代码实际上是正确的。

Answer 3

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;
}
}

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);
                    }
                });
    }
}

在 PHP 代码中 使用 print_r 代替打印