Question

我创建了一个Android应用，通过使用 MySQL数据库和 PHP 输入他的详细信息来检索学生的百分比。

activity_main.xml包含两个Buttons“登录 - 获取”和“登录帖子”，单击它们将获得结果值使用Get和Post方法从数据库中获取。

我已经从上面的教程中下载了整个代码，并对MySQL URL进行了一些更改。该应用程序完美无缺。但是当我尝试删除activity_main.xml中的“Login-Post”按钮和“Login Method”文本视图时，应用程序会显示"Unfortunately PHPMYSQL stopped working"之类的错误。

这是我的完整代码：

MainActivity.java

package com.mycompany.nec;

import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.view.View;
import android.widget.EditText;
import android.widget.TextView;

public class MainActivity extends Activity {

    private EditText usernameField,passwordField;
    private TextView status,role,method;

    @Override 
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        usernameField = (EditText)findViewById(R.id.editText1);
        passwordField = (EditText)findViewById(R.id.editText2);
        status = (TextView)findViewById(R.id.textView6);
        role = (TextView)findViewById(R.id.textView7);
        method = (TextView)findViewById(R.id.textView9);
    }

    public void login(View view) {
        String username = usernameField.getText().toString();
        String password = passwordField.getText().toString();
        method.setText("Get Method");
        new SigninActivity(this,status,role,0).execute(username,password);       
    }

    public void loginPost(View view) {
        String username = usernameField.getText().toString();
        String password = passwordField.getText().toString();
        method.setText("Post Method");
        new SigninActivity(this,status,role,1).execute(username,password);
    }
}

SigninActivity.java

package com.mycompany.nec;

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.net.URI;
import java.net.URL;
import java.net.URLConnection;
import java.net.URLEncoder;

import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;

import android.content.Context;
import android.os.AsyncTask;
import android.widget.TextView;

public class SigninActivity  extends AsyncTask<String,Void,String> {

    private TextView statusField,roleField;
    private Context context;
    private int byGetOrPost = 0; 
    //flag 0 means get and 1 means post.(By default it is get.)
    public SigninActivity(Context context,TextView statusField,
    TextView roleField,int flag) {
        this.context = context;
        this.statusField = statusField;
        this.roleField = roleField;
        byGetOrPost = flag;
    }

    protected void onPreExecute() {

    }
    @Override
    protected String doInBackground(String... arg0) {
        if(byGetOrPost == 0){ //means by Get Method
            try {
                String username = (String)arg0[0];
                String password = (String)arg0[1];
                String link = "http://necrecords.webatu.com/login.php?username="+username+"&password="+password;
                URL url = new URL(link);
                HttpClient client = new DefaultHttpClient();
                HttpGet request = new HttpGet();
                request.setURI(new URI(link));
                HttpResponse response = client.execute(request);
                BufferedReader in = new BufferedReader (new InputStreamReader(response.getEntity().getContent()));

                StringBuffer sb = new StringBuffer("");
                String line="";
                while ((line = in.readLine()) != null) {
                    sb.append(line);
                    break;
                }
                in.close();
                return sb.toString();
            } catch(Exception e) {
                return new String("Exception: " + e.getMessage());
            }
        }
        else {
            try {
                String username = (String)arg0[0];
                String password = (String)arg0[1];
                String link="http://necrecords.webatu.com/loginpost.php";
                String data  = URLEncoder.encode("username", "UTF-8") + "=" + URLEncoder.encode(username, "UTF-8");
                data += "&" + URLEncoder.encode("password", "UTF-8") + "=" + URLEncoder.encode(password, "UTF-8");
                URL url = new URL(link);
                URLConnection conn = url.openConnection(); 
                conn.setDoOutput(true); 
                OutputStreamWriter wr = new OutputStreamWriter(conn.getOutputStream()); 
                wr.write( data ); 
                wr.flush(); 
                BufferedReader reader = new BufferedReader(new InputStreamReader(conn.getInputStream()));
                StringBuilder sb = new StringBuilder();
                String line = null;
                // Read Server Response
                while((line = reader.readLine()) != null)
                {
                    sb.append(line);
                    break;
                }
                return sb.toString();
            } catch(Exception e) {
                return new String("Exception: " + e.getMessage());
            }
        }
    }

    @Override
    protected void onPostExecute(String result) {
        this.statusField.setText("Login Successful");
        this.roleField.setText(result);
    }
}

activiy_main.xml

<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"
   tools:context=".MainActivity" >

   <EditText
      android:id="@+id/editText2"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_alignRight="@+id/editText1"
      android:layout_below="@+id/editText1"
      android:layout_marginTop="25dp"
      android:ems="10"
      android:inputType="textPassword" >
   </EditText>

   <EditText
      android:id="@+id/editText1"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_alignParentRight="true"
      android:layout_alignParentTop="true"
      android:layout_marginTop="44dp"
      android:ems="10" >

   <requestFocus android:layout_width="wrap_content" />

   </EditText>

   <TextView
      android:id="@+id/textView1"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_alignBottom="@+id/editText1"
      android:layout_alignParentLeft="true"
      android:text="@string/Username" />

   <TextView
      android:id="@+id/textView3"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_alignParentTop="true"
      android:layout_centerHorizontal="true"
      android:text="@string/App"
      android:textAppearance="?android:attr/textAppearanceLarge" />

   <TextView
      android:id="@+id/textView7"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_alignBottom="@+id/textView5"
      android:layout_alignLeft="@+id/textView6"
      android:text="@string/Role"
      android:textAppearance="?android:attr/textAppearanceMedium"
      android:textSize="10sp" />

   <TextView
      android:id="@+id/textView5"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_below="@+id/textView6"
      android:layout_marginTop="27dp"
      android:layout_toLeftOf="@+id/editText1"
      android:text="@string/LoginRole" />
   <TextView
      android:id="@+id/textView8"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_above="@+id/textView6"
      android:layout_alignLeft="@+id/textView5"
      android:layout_marginBottom="27dp"
      android:text="@string/method" />

   <TextView
      android:id="@+id/textView4"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_alignLeft="@+id/textView8"
      android:layout_below="@+id/button1"
      android:layout_marginTop="86dp"
      android:text="@string/LoginStatus" />


   <TextView
      android:id="@+id/textView6"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_alignTop="@+id/textView4"
      android:layout_centerHorizontal="true"
      android:text="@string/Status"
      android:textAppearance="?android:attr/textAppearanceMedium"
      android:textSize="10sp" />

   <TextView
      android:id="@+id/textView9"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_alignBottom="@+id/textView8"
      android:layout_alignLeft="@+id/textView6"
      android:text="@string/Choose"
      android:textAppearance="?android:attr/textAppearanceMedium"
      android:textSize="10sp" />

   <Button
      android:id="@+id/button2"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_centerVertical="true"
      android:layout_toRightOf="@+id/textView6"
      android:onClick="loginPost"
      android:text="@string/LoginPost" />

   <Button
      android:id="@+id/button1"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_alignBaseline="@+id/button2"
      android:layout_alignBottom="@+id/button2"
      android:layout_alignLeft="@+id/textView2"
      android:onClick="login"
      android:text="@string/LoginGet" />

   <TextView
      android:id="@+id/textView2"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_alignBaseline="@+id/editText2"
      android:layout_alignBottom="@+id/editText2"
      android:layout_alignParentLeft="true"
      android:text="@string/Password" />

</RelativeLayout>

的AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
   package="com.mycompany.nec"
   android:versionCode="1"
   android:versionName="1.0" >

   <uses-sdk
      android:minSdkVersion="8"
      android:targetSdkVersion="17" />
   <uses-permission android:name="android.permission.INTERNET"/>
   <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
   <application
      android:allowBackup="true"
      android:icon="@drawable/ic_launcher"
      android:label="@string/app_name">
      <activity
         android:name="com.mycompany.nec.MainActivity"
         android:label="@string/app_name" >
         <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />
         </intent-filter>
      </activity>
   </application>
</manifest>

对此有任何帮助将不胜感激。

无法将Android应用程序连接到mysql数据库

0 个答案: