Question

我已成功创建了登录页面...我已成功检查了我的数据库的用户名和密码。然后我设置了条件if(result!=null)表示启动第二个活动。我现在得到的是什么，即使用户名或密码也不正确，它也会启动第二页。我需要做些什么来制作正确的登录界面... Suggesstion plz，提前致谢

AsynTask onpostexecute函数

 protected void onPostExecute(String result) {
        //View your result here.
           if(result!= null) 
           {
               val=result;
               Intent intent=new Intent(Login.this,Child_Profile.class);
               intent.putExtra("child_name", result);
               startActivity(intent);

           }

    }

我的login.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:weightSum="6"
    android:background="#1E8EB6" >
<RelativeLayout
    android:layout_width="match_parent"
    android:layout_height="0dp"

    android:background="#1E8EB6"
    android:layout_weight="1.5">

    <TextView
        android:id="@+id/textView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/imageView1"
        android:layout_centerHorizontal="true"
        android:gravity="center_vertical"
        android:text="@string/title"
        android:textColor="#FFFFFF"
        android:textSize="30sp" />

    <ImageView
        android:id="@+id/imageView1"
        android:layout_width="50dp"
        android:layout_height="50dp"
        android:layout_alignLeft="@+id/textView1"
        android:layout_alignParentTop="true"
        android:layout_marginLeft="94dp"
        android:layout_marginTop="21dp"
        android:contentDescription="@string/title_img"
        android:src="@drawable/camera" />

  </RelativeLayout>




<RelativeLayout
    android:layout_width="match_parent"
    android:layout_height="0dp"
    android:background="#00677F"
    android:layout_weight="3.5"
    android:paddingLeft="10dp"
    android:paddingRight="10dp"
    android:layout_marginLeft="10dp"
    android:layout_marginRight="10dp"

    >

    <EditText
        android:id="@+id/username"
        android:layout_width="match_parent"
        android:layout_height="40dp"
        android:layout_alignParentTop="true"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="30dp"
        android:layout_marginBottom="10dp"
        android:paddingLeft="5dp"
        android:ems="10" 
        android:background="#FFFFFF"
        android:drawableLeft="@android:drawable/stat_notify_more"
        android:inputType="text"
        android:gravity="center_vertical"
        android:hint="@string/username">

        <requestFocus />
    </EditText>

    <EditText
        android:id="@+id/password"
        android:layout_width="match_parent"
        android:layout_height="40dp"
        android:layout_below="@+id/username"
        android:layout_centerHorizontal="true"
        android:ems="10" 
        android:background="#FFFFFF"
        android:drawableStart="@android:drawable/ic_secure"
        android:inputType="textPassword"
        android:paddingLeft="5dp"
        android:gravity="center_vertical"
         android:hint="@string/password"/>

    <Button
        android:id="@+id/login"
        android:layout_width="100dp"
        android:layout_height="40dp"
        android:layout_alignRight="@+id/password"
        android:layout_below="@+id/password"
        android:layout_marginTop="19dp"
        android:text="@string/login" 
        android:background="#054579"
        android:textColor="#FFFFFF" />

    <CheckBox
        android:id="@+id/remember"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignBaseline="@+id/login"
        android:layout_alignBottom="@+id/login"
        android:layout_alignLeft="@+id/password"
        android:text="@string/remember" 
        android:textColor="#FFFFFF"/>

    <Button
        android:id="@+id/forget"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:layout_centerHorizontal="true"
        android:layout_marginBottom="18dp"
        android:text="@string/forget"
        android:textColor="#FFFFFF" 
        style="?android:attr/borderlessButtonStyle"
        android:textSize="20sp" />

  </RelativeLayout>


<RelativeLayout
    android:layout_width="match_parent"
    android:layout_height="0dp"
    android:layout_weight="1"


    android:paddingRight="10dp"
    android:layout_marginLeft="10dp"
    android:layout_marginRight="10dp">

    <Button
        android:id="@+id/signup"
        android:layout_width="150dp"
        android:layout_height="40dp"
        android:layout_alignParentRight="true"
        android:layout_centerVertical="true"
        android:background="#054579"
        android:text="@string/signup"
        android:textColor="#FFFFFF" />

  </RelativeLayout>




</LinearLayout>

我的Login.java，最终工作代码

   package com.example.certify.schoolapp;

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

import android.app.Activity;
import android.content.Intent;
import android.os.AsyncTask;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;

public class Login extends Activity {
    private TextView head;
    private EditText username,password;
    private Button login,signup,forget;
    private static String user,pass,val,result="";

@Override
protected void onCreate(Bundle savedInstanceState) {
    // TODO Auto-generated method stub
    super.onCreate(savedInstanceState);
    setContentView(R.layout.login);
    head=(TextView) findViewById(R.id.textView1);
    username=(EditText) findViewById(R.id.username);
    password=(EditText) findViewById(R.id.password);
    login=(Button) findViewById(R.id.login);
    signup=(Button) findViewById(R.id.signup);
    forget=(Button) findViewById(R.id.forget);
    login.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub
            new sendPostData().execute();

        }
    });
}

private class sendPostData extends AsyncTask<String, Void, String>
{
        @Override
    protected String doInBackground(String... params) {  

 try{

             user = username.getText().toString(); 
             pass = password.getText().toString();
             String link="http://192.168.1.5:81/arun/loginpost.php?";
                String data  = URLEncoder.encode("username", "UTF-8") 
                + "=" + URLEncoder.encode(user, "UTF-8");
                data += "&" + URLEncoder.encode("password", "UTF-8") 
                + "=" + URLEncoder.encode(pass, "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) {
        //View your result here.
           if(result.equals("wrong"))
           {
               Toast toast=Toast.makeText(Login.this,"incorrect password", Toast.LENGTH_LONG);
               toast.show(); 
           }
           else
           {
               Intent intent=new Intent(Login.this,Child_Profile.class);
               intent.putExtra("child_name", result);
               startActivity(intent);
           }




        }
 }
}

我的loginpost.php

<?php
$con=mysql_connect("localhost","arun","sachin11");

$db_select = mysql_select_db('my_db', $con);
$username = $_POST['username'];
$password = $_POST['password'];
$result = mysql_query("SELECT Role FROM table1 where Username='$username' and Password='$password'",$con);
$row = mysql_fetch_array($result);
$data = $row[0];
if($data){
echo $data;
}
else 
{
    echo "wrong";
}
mysql_close($con);
?>

Answer 1

无论您从doInBackground传出什么，因为字符串值是Result中的onPostExecute。

查看您的doInBackground似乎没有返回字符串永远不会是null的路径。

此外，检查是否设置或不设置为用户成功验证的指示是不好的。我会使用用户详细信息传回一个布尔或更好的用户对象。

我会改变：

 if(result!= null)

到

 if(result.eques("OK"))

其中OK是成功登录时服务器的预期响应。 [不是真的推荐，我怀疑你的PHP脚本会返回它。]

Android登录界面用php mysql

1 个答案: