使用安卓 JSON 检查数据库中是否存在数据 - check if data exist in database using android json

我正在使用Eclipse开发一个应用程序。我正在尝试使用 json 检查数据库中是否存在 IC。我进行编码，当我运行它时出现错误。数据库配置是正确的，因为我已经尝试了使用其他文件的配置并且工作正常。计划是：

编辑文本中的输入 IC ： icno_manual
单击按钮签入并在数据库中搜索 IC。
如果找到，则返回成功
如果TAG_SUCCESS为 1，则将文本视图msgResult_manual设置为"签入成功"

请帮助我。这是我的XML，Java和PHP。提前谢谢。表详细信息：骑手 [ID（PK）- 整数，名称-瓦尔查尔， IC（唯一）-瓦尔查尔]

XML 文件

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context="com.example.trialonlistview.MainActivity" >
<TextView
    android:id="@+id/msgResult_manual"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_centerHorizontal="true"
    android:layout_centerVertical="true"
    android:text="@string/msgResult_manual"
    android:textAppearance="?android:attr/textAppearanceMedium" />
<EditText
    android:id="@+id/icno_manual"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentLeft="true"
    android:layout_alignParentRight="true"
    android:layout_below="@+id/NRIC_manual"
    android:layout_marginTop="22dp"
    android:ems="10"
    android:inputType="textCapCharacters" >
    <requestFocus />
</EditText>
<Button
    android:id="@+id/btnSearch_manual"
    style="?android:attr/buttonStyleSmall"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignRight="@+id/icno_manual"
    android:layout_below="@+id/icno_manual"
    android:layout_marginRight="16dp"
    android:text="@string/btnScan_manual" />
<TextView
    android:id="@+id/NRIC_manual"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentLeft="true"
    android:layout_alignParentTop="true"
    android:text="@string/NRIC_manual"
    android:textAppearance="?android:attr/textAppearanceMedium" />

爪哇编辑 1

package com.example.trialonlistview;
import java.util.ArrayList;
import java.util.List;
import org.apache.http.NameValuePair;
import org.apache.http.message.BasicNameValuePair;
import org.json.JSONException;
import org.json.JSONObject;
import android.app.Activity;
import android.app.ProgressDialog;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
public class MainActivity extends Activity {
Button checkIn;
EditText icnotxt;
TextView result;
JSONParser jsonParser = new JSONParser();
private ProgressDialog pDialog;
private static String icno;
// url to check-in manual
private static String url_manual = "http://192.168.0.25/check/check.php";
// JSON Node names
private static final String TAG_SUCCESS = "success";
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    icnotxt = (EditText)findViewById(R.id.icno_manual);
    checkIn = (Button)findViewById(R.id.btnSearch_manual);
    result = (TextView)findViewById(R.id.msgResult_manual); 
    // check-in button click event
    checkIn.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View arg0) {
            // creating new product in background thread
            new CheckIn().execute();
        }
    });     
}
//manual check-in
//Background Async Task to check-in manually
class CheckIn extends AsyncTask<String, String, String> {
    @Override
    protected void onPreExecute() {
        super.onPreExecute();
        pDialog = new ProgressDialog(MainActivity.this);
        pDialog.setMessage("Check-in...");
        pDialog.setIndeterminate(false);
        pDialog.setCancelable(true);
        pDialog.show();
        //add in
        icno = icnotxt.getText().toString();
    }
    //check-in
    protected String doInBackground(String... args) {
        // Building Parameters
        List<NameValuePair> params = new ArrayList<NameValuePair>();
        params.add(new BasicNameValuePair("icno", icno));
        JSONObject json = jsonParser.makeHttpRequest(url_manual,
                "POST", params);
        // check log cat from response
        Log.d("Check-in response", json.toString());
        // check for success tag
        int success;
        try {
            success = json.getInt(TAG_SUCCESS);
            if (success == 1) {
                // successfully check-in
                result.setText("Check-in success");
            } else {
                // failed to check-in
                result.setText("Failed");
            }
        } catch (JSONException e) {
            e.printStackTrace();
        }
        return null;
    }
    protected void onPostExecute(String file_url) {
        // dismiss the dialog once done
        pDialog.dismiss();
    }
}
//manual check-in end
@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.main, menu);
    return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int id = item.getItemId();
    if (id == R.id.action_settings) {
        return true;
    }
    return super.onOptionsItemSelected(item);
}
}

.PHP

<?php
// array for JSON response
$response = array();
// check for required fields
if (isset($_POST['icno'])) {
$icno = $_POST['icno'];
// include db connect class
//require_once __DIR__ . '/db_connect.php'; 
require_once '/db_connect.php';
// connecting to db
$db = new DB_CONNECT();
$result = mysql_query("SELECT ID FROM rider WHERE IC = $icno");
// check if found
if (mysql_num_rows($result) > 0) {
    // found
    $response["success"] = 1;
    $response["message"] = "found";
    // echoing JSON response
    echo json_encode($response);
} else {
    // not found
    $response["success"] = 0;
    $response["message"] = "Not found";
    // echoing JSON response
    echo json_encode($response);
}
} else {
    // required field is missing
    $response["success"] = 0;
    $response["message"] = "Required field(s) is missing";
    // echoing JSON response
    echo json_encode($response);
}
?>

错误已编辑 1

11-28 10:55:26.802: E/AndroidRuntime(31123): FATAL EXCEPTION: AsyncTask #1
11-28 10:55:26.802: E/AndroidRuntime(31123): java.lang.RuntimeException: An error occured while executing doInBackground()
11-28 10:55:26.802: E/AndroidRuntime(31123):    at android.os.AsyncTask$3.done(AsyncTask.java:299)
11-28 10:55:26.802: E/AndroidRuntime(31123):    at java.util.concurrent.FutureTask$Sync.innerSetException(FutureTask.java:273)
11-28 10:55:26.802: E/AndroidRuntime(31123):    at java.util.concurrent.FutureTask.setException(FutureTask.java:124)
11-28 10:55:26.802: E/AndroidRuntime(31123):    at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:307)
11-28 10:55:26.802: E/AndroidRuntime(31123):    at java.util.concurrent.FutureTask.run(FutureTask.java:137)
11-28 10:55:26.802: E/AndroidRuntime(31123):    at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:230)
11-28 10:55:26.802: E/AndroidRuntime(31123):    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1076)
11-28 10:55:26.802: E/AndroidRuntime(31123):    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:569)
11-28 10:55:26.802: E/AndroidRuntime(31123):    at java.lang.Thread.run(Thread.java:856)
11-28 10:55:26.802: E/AndroidRuntime(31123): Caused by: android.view.ViewRootImpl$CalledFromWrongThreadException: Only the original thread that created a view hierarchy can touch its views.
11-28 10:55:26.802: E/AndroidRuntime(31123):    at android.view.ViewRootImpl.checkThread(ViewRootImpl.java:4618)
11-28 10:55:26.802: E/AndroidRuntime(31123):    at android.view.ViewRootImpl.requestLayout(ViewRootImpl.java:839)
11-28 10:55:26.802: E/AndroidRuntime(31123):    at android.view.View.requestLayout(View.java:15323)
11-28 10:55:26.802: E/AndroidRuntime(31123):    at android.view.View.requestLayout(View.java:15323)
11-28 10:55:26.802: E/AndroidRuntime(31123):    at android.view.View.requestLayout(View.java:15323)
11-28 10:55:26.802: E/AndroidRuntime(31123):    at android.view.View.requestLayout(View.java:15323)
11-28 10:55:26.802: E/AndroidRuntime(31123):    at android.widget.RelativeLayout.requestLayout(RelativeLayout.java:297)
11-28 10:55:26.802: E/AndroidRuntime(31123):    at android.view.View.requestLayout(View.java:15323)
11-28 10:55:26.802: E/AndroidRuntime(31123):    at android.widget.TextView.checkForRelayout(TextView.java:6377)
11-28 10:55:26.802: E/AndroidRuntime(31123):    at android.widget.TextView.setText(TextView.java:3577)
11-28 10:55:26.802: E/AndroidRuntime(31123):    at android.widget.TextView.setText(TextView.java:3435)
11-28 10:55:26.802: E/AndroidRuntime(31123):    at android.widget.TextView.setText(TextView.java:3410)
11-28 10:55:26.802: E/AndroidRuntime(31123):    at com.example.trialonlistview.MainActivity$CheckIn.doInBackground(MainActivity.java:95)
11-28 10:55:26.802: E/AndroidRuntime(31123):    at com.example.trialonlistview.MainActivity$CheckIn.doInBackground(MainActivity.java:1)
11-28 10:55:26.802: E/AndroidRuntime(31123):    at android.os.AsyncTask$2.call(AsyncTask.java:287)
11-28 10:55:26.802: E/AndroidRuntime(31123):    at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:305)

您正在访问 doInBackground（）中的 UI 元素。您只能在主线程上使用 UI 元素

因此，在 CheckIn 类中String icno全局，然后将以下行移动到 onPreExecute()

icno = icnotxt.getText().toString();

编辑

将字符串返回到 onPostExecute()以便onPostExecute()处理将结果文本添加到 result textView。因此，在'doInBackground（）中更改以下行：

// check for success tag
    int success;
    try {
        success = json.getInt(TAG_SUCCESS);
        if (success == 1) {
            // successfully check-in
            return "Check-in success";
        } else {
            // failed to check-in
            return "Failed";
        }
    } catch (JSONException e) {
        e.printStackTrace();
    }

并在onPostExecute()中更改以下内容

protected void onPostExecute(String file_url) {
    // dismiss the dialog once done
    pDialog.dismiss();
    result.setText(file_url); //file_url will have the following values either Check-in success or failed
}

给我反馈，无论这是否对你有帮助。