Question

 main xml file
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent" 
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:paddingBottom="@dimen/activity_vertical_margin"
    app:layout_behavior="@string/appbar_scrolling_view_behavior"
    tools:showIn="@layout/activity_main" tools:context=".MainActivity">

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="ADD CONTACT"
        android:id="@+id/btnadd"
        android:layout_alignParentTop="true"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="97dp"
        android:onClick="addContact"/>

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="VIEW CONTACT"
        android:id="@+id/btnview"
        android:layout_centerVertical="true"
        android:layout_centerHorizontal="true"
        android:onClick="viewContact"/>

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="No Network Found"
        android:id="@+id/textview"
        android:layout_below="@+id/btnview"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="55dp" />
</RelativeLayout>





 main java file
    package com.example.dota.databasephp;

    import android.app.Activity;
    import android.content.Context;
    import android.content.Intent;
    import android.net.ConnectivityManager;
    import android.net.NetworkInfo;
    import android.os.Bundle;
    import android.view.View;
    import android.widget.Button;
    import android.widget.TextView;

    public class MainActivity extends Activity implements View.OnClickListener {


        Button btnadd,btnview;
        TextView textView;


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

            btnadd = (Button) findViewById(R.id.btnadd);
            btnview = (Button) findViewById(R.id.btnview);
            textView = (TextView) findViewById(R.id.textview);
            btnadd.setOnClickListener(this);
            ConnectivityManager connectivityManager = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
            NetworkInfo networkInfo = connectivityManager.getActiveNetworkInfo();

            if (networkInfo != null && networkInfo.isConnected())
            {
                textView.setVisibility(View.INVISIBLE);

            }
            else {
                btnadd.setEnabled(false);
                btnview.setEnabled(false);
            }
        }


        @Override
        public void onClick(View v) {
            Intent i=new Intent(MainActivity.this,Addinfo.class);
            startActivity(i);
        }


    }



addinfo xml file

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    xmlns:app="http://schemas.android.com/apk/res-auto" 
    android:layout_width="match_parent"
    android:layout_height="match_parent" 
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:paddingBottom="@dimen/activity_vertical_margin"
    app:layout_behavior="@string/appbar_scrolling_view_behavior"
    tools:showIn="@layout/activity_addinfo" 
    tools:context="com.example.dota.databasephp.Addinfo">
    <EditText
        android:layout_width="250dp"
        android:layout_height="wrap_content"
        android:id="@+id/et_name"
        android:layout_alignParentTop="true"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="59dp"
        android:text="Enter Name" />

    <EditText
        android:layout_width="250dp"
        android:layout_height="wrap_content"
        android:id="@+id/et_email"
        android:text="Enter Email"
        android:layout_below="@+id/et_name"
        android:layout_alignLeft="@+id/et_name"
        android:layout_alignStart="@+id/et_name"
        android:layout_marginTop="34dp"
        android:inputType="textEmailAddress"/>

    <EditText
        android:layout_width="250dp"
        android:layout_height="wrap_content"
        android:id="@+id/et_mobile"
        android:text="Enter Mobile"
        android:layout_below="@+id/et_email"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="37dp"
        android:inputType="phone"/>

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="SAVE DATA"
        android:id="@+id/button"
        android:layout_below="@+id/et_mobile"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="78dp"
        android:onClick="saveInfo"/>

</RelativeLayout>


addinfo java file
package com.example.dota.databasephp;

import android.app.Activity;
import android.os.AsyncTask;
import android.os.Bundle;
import android.view.View;
import android.widget.EditText;
import android.widget.Toast;

import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLEncoder;

public class Addinfo extends Activity {
    EditText Name,Email,Mobile;
    String name,email,mobile;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_addinfo);
        Name=(EditText)findViewById(R.id.et_name);
        Email=(EditText)findViewById(R.id.et_email);
        Mobile=(EditText)findViewById(R.id.et_mobile);

        BackgroundTask backgroundTask=new BackgroundTask();
        backgroundTask.execute(name,email,mobile);
        finish();
    }
    public void saveInfo(View view)
    {
        name= Name.getText().toString();
        email=Email.getText().toString();
        mobile=Mobile.getText().toString();
    }

    class BackgroundTask extends AsyncTask<String, String, String>
    {
        String add_info_url;

        @Override
        protected void onPreExecute() {
            add_info_url="Domain_name/add_info.php";
        }

        @Override
        protected String doInBackground(String... params) {
            String name,email,mobile;
            name=params[0];
            email=params[1];
            mobile=params[2];
            try {
                URL url=new URL(add_info_url);
                HttpURLConnection httpURLConnection= (HttpURLConnection)url.openConnection();
                httpURLConnection.setRequestMethod("POST");
                httpURLConnection.setDoOutput(true);
                OutputStream outputStream=httpURLConnection.getOutputStream();
                BufferedWriter bufferedWriter= new BufferedWriter(new OutputStreamWriter(outputStream,"UTF-8"));
                String data_string= URLEncoder.encode("name", "UTF-8")+"="+URLEncoder.encode(name,"UTF-8")+"="+
                        URLEncoder.encode("email","UTF-8")+"="+URLEncoder.encode(email,"UTF-8")+"="+
                        URLEncoder.encode("mobile","UTF-8")+"="+URLEncoder.encode(mobile,"UTF-8");
                bufferedWriter.write(data_string);
                bufferedWriter.flush();
                bufferedWriter.close();
                outputStream.close();
                InputStream inputStream=httpURLConnection.getInputStream();
                inputStream.close();
                httpURLConnection.disconnect();

                return "One row of data inserted";


            } catch (MalformedURLException e) {
                e.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            }

            return null;
        }

        @Override
        protected void onPostExecute(String result) {
            Toast.makeText(getApplicationContext(), result, Toast.LENGTH_LONG).show();
        }

        @Override
        protected void onProgressUpdate(String... values) {
            super.onProgressUpdate(values);
        }
    }

}

当我点击添加联系人按钮执行此代码后，会出现一个非常小的框。那个小盒子是什么？我没理解为什么这个盒子出现在执行中。请运行代码，您将了解问题所在。

screenshot

Answer 1

您正在Addinfo中拨打finish()来销毁onCreate()个活动。

尝试删除此行：

finish();

来自您onCreate()活动的Addinfo。

点击小窗口后打开instaed of opning full activity

1 个答案: