Question

我试图在我的应用中制作一个简单的消息系统。用户在屏幕底部的EditText中键入消息。不知何故，屏幕上显示的EditText实际上并不是我使用findViewById()获得的EditText。

我尝试将默认值添加到xml中的editText.getText()并且它可以正常工作。但是，如果我更改默认文本，屏幕上的文本会更改，但editText.setText()仍会返回默认值。 editText.getText()不会更改屏幕上显示的文字，但会更改实际值（<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" xmlns:app="http://schemas.android.com/apk/res-auto" tools:context="com.gloriovin.helpio.Views.MessageFragment" android:id="@+id/message_fragment" android:orientation="vertical"> <ListView android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_above="@+id/sendMessageSection" android:id="@+id/listView" android:clipToPadding="false" android:divider="@color/Transparent" android:stackFromBottom="true" android:transcriptMode="alwaysScroll"></ListView> <RelativeLayout android:layout_width="match_parent" android:layout_height="45dp" android:id="@+id/sendMessageSection" android:layout_alignParentBottom="true" android:background="@color/LightGrey"> <com.mikepenz.iconics.view.IconicsImageView android:layout_width="wrap_content" android:layout_height="match_parent" android:id="@+id/sendButton" android:layout_alignParentRight="true" android:layout_centerVertical="true" android:layout_marginRight="3dp" app:iiv_size="25dp" app:iiv_color="@color/DarkGrey" app:iiv_icon="gmd-send" /> <EditText android:layout_width="match_parent" android:layout_height="match_parent" android:id="@+id/messageField" android:layout_toLeftOf="@id/sendButton" android:singleLine="true" android:text="kuda" android:layout_marginLeft="10dp" android:layout_marginRight="3dp" android:gravity="bottom"/> </RelativeLayout> </RelativeLayout>会返回新文字）。

这是我的代码：

fragment_message.xml

import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;

import com.gloriovin.helpio.R;

public class ChatActivity extends AppCompatActivity {

    private Toolbar toolbar;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_chat);
        toolbar = (Toolbar) findViewById(R.id.toolbar);
        toolbar.setTitle("Message");

        MessageFragment messageFragment = new MessageFragment();
    getSupportFragmentManager().beginTransaction().replace(R.id.fragment, messageFragment).    commit();

    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_message, 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();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }

}

chatActivity.java

import android.app.Activity;
import android.net.Uri;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.design.widget.FloatingActionButton;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.EditText;
import android.widget.ListView;

import com.gloriovin.helpio.Adapters.friendAdapters;
import com.gloriovin.helpio.Adapters.messageAdapters;
import com.gloriovin.helpio.Globals;
import com.gloriovin.helpio.HelpioApp;
import com.gloriovin.helpio.Models.Message;
import com.gloriovin.helpio.Models.MessageRoom;
import com.gloriovin.helpio.R;
import com.mikepenz.iconics.view.IconicsImageView;

import org.json.JSONException;
import org.json.JSONObject;

import java.util.ArrayList;
import java.util.zip.Inflater;

import cz.msebera.android.httpclient.Header;
import io.paperdb.Paper;


public class MessageFragment extends Fragment {
    private Activity activity;
    private int mid;
    public MessageFragment() {
    }

    @Override
    public void onAttach(Activity activity) {
        super.onAttach(activity);
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        return inflater.inflate(R.layout.fragment_message, container, false);

    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        mid = getActivity().getIntent().getIntExtra("mid", -1);
        this.activity  = getActivity();
        Log.e("mid", String.valueOf(mid));
    }

    @Override
    public void onActivityCreated(Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);



        ListView listView = (ListView) getActivity().findViewById(R.id.listView);
        messageAdapters adapter = new messageAdapters(getActivity(), FAKECHAT);
        listView.setDivider(null);
        listView.setAdapter(adapter);


        IconicsImageView sendButton = (IconicsImageView) getActivity().findViewById(R.id.    sendButton);
        sendButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                EditText newMessage = (EditText) getActivity().findViewById(R.id.messageField);
                String msg = newMessage.getText().toString();
                Log.e("message is", "asd"+msg);
            }
        });
    }

    @Override
    public void onDetach() {
        super.onDetach();
    }
}

messageFragment.java

messageFragment.java

TLDR：在EditText中，EditText值（.getText（））与setText()中实际输入的值不同（空字符串＆＃34;＆＃34;）。 EditText并未更改getText()的外观，但会更改<?php final class crud { private $connexionName, $sql = ''; public function __construct($connexionName) { $this->connexionName = $connexionName; } public final function insert($tableName, $fields=array()){ $this->tableName = $tableName; $this->fields = $fields; foreach ($this->fields as $vf) { $inKeys[] = $vf; $inKeysDotted[] = ':' . $vf; $insImKeys = implode(', ', $inKeys); $insImKeysDotted = implode(', ', $inKeysDotted); $this->insImKeys = $insImKeys; $this->insImKeysDotted = $insImKeysDotted; } $this->insertedKeys = $inKeys; $this->insertedKeysDotted = $inKeysDotted; $sql = "INSERT INTO `$this->tableName` ($this->insImKeys) VALUES ($this->insImKeysDotted);"; //echo $sql.'<br />'; $insertItems = $this->connexionName->prepare($sql); $this->insertItems = $insertItems; echo '<pre>'; print_r($insertItems).'<br />'; echo '</pre>'; } // end prepareStm() public final function checkValType($valToCheck){ $this->valToCheck = $valToCheck; // http://php.net/manual/en/function.gettype.php $valType = gettype($this->valToCheck); $this->valType = $valType; switch ($this->valType) { case 'boolean': $PDOType = PDO::PARAM_BOOL; break; case 'integer': $PDOType = PDO::PARAM_INT; break; case 'NULL': $PDOType = PDO::PARAM_NULL; break; default: // string $PDOType = PDO::PARAM_STR; break; } //echo $PDOType.'<br />'; $this->PDOType = $PDOType; //return $this->valType; return $this->PDOType; } // end checkValType() public final function bindParams($setValues=array()){ $combine = array_combine($this->insertedKeys, $setValues); foreach ($combine as $getKey => $getVal) { $setType = $this->checkValType($getVal); echo "this->insertItems->bindValue($getKey, $getVal, $setType)<br />"; $this->insertItems->bindValue($getKey, $getVal, $setType); } } // end bindParams() public final function executeQuery(){ return $this->insertItems->execute(); } } require_once '../Included_Files/Connect.php'; $con = new crud($connexion); echo '<br />'; $con->insert('test', array('field1', 'field2', 'field3')); //$con->checkValType(19); $con->bindParams(array('<script>alert(\'hello\');</script>', 'pour field2', 'pour field3')); $con->executeQuery();的结果

Answer 1

下面：

EditText newMessage = (EditText) getActivity().findViewById(R.id.messageField);

可能获得NPE Exception，因为newMessage是null。

带有EditText的

messageField位于fragment_message布局内，这是Fragment的布局。所以使用getView方法初始化newMessage对象而不是getActivity()，它返回片段当前可用的活动上下文。

覆盖onViewCreated并使用v.findViewById初始化所有观看次数：

ListView listView;
IconicsImageView sendButton;
EditText newMessage;
public void onViewCreated(View v, Bundle savedInstanceState) {
    super.onViewCreated(v, savedInstanceState);
    listView = (ListView) v.findViewById(R.id.listView);
    sendButton = (IconicsImageView) v.findViewById(R.id.    sendButton);
    newMessage = (EditText) v.findViewById(R.id.messageField);
}

Answer 2

在点击侦听器之外写下此行

EditText newMessage = (EditText) getActivity().findViewById(R.id.messageField);

Answer 3

您没有正确获取EditText。

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    mView = inflater.inflate(R.layout.fragment_message, container, false);
    newMessage = (EditText) mView.findViewById(R.id.messageField);

    String msg = newMessage.getText().toString();
    return mView;
}

EditText可编辑但getText（）返回空字符串

3 个答案: