Question

我在点击登录（按钮）后尝试阅读w_number_edit_text（文本框）的内容。但是在OnClick方法上，我似乎无法访问w_number_edit_text的内容。文本框和按钮都位于片段xml而不是main.xml上。谁能告诉我如何解决这个问题。简而言之，如何在点击EditText后访问Button的内容？谢谢你我的代码如下：

 package com.example.medrec;
    import android.support.v7.app.ActionBarActivity;
    import android.support.v7.app.ActionBar;
    import android.support.v4.app.Fragment;
    import android.app.AlertDialog;
    import android.os.Bundle;
    import android.view.LayoutInflater;
    import android.view.Menu;
    import android.view.MenuItem;
    import android.view.View;
    import android.view.View.OnClickListener;
    import android.view.ViewGroup;
    import android.view.Window;
    import android.view.WindowManager;
    import android.webkit.WebView.FindListener;
    import android.widget.Button;
    import android.widget.EditText;
    import android.widget.Toast;
    import android.os.Build;

    public class MainActivity extends ActionBarActivity {

    Button login;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

        if (savedInstanceState == null) {
            getSupportFragmentManager().beginTransaction()
                    .add(R.id.container, new PlaceholderFragment())
                    .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.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);
    }

    /**
     * A placeholder fragment containing a simple view.
     */
    public static class PlaceholderFragment extends Fragment implements OnClickListener{

        public PlaceholderFragment() {
        }

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

            Button login = (Button)rootView.findViewById(R.id.w_login);
            login.setOnClickListener(this);
            return rootView;
        }

        @Override
        public void onClick(View v) {
            //////////////////////////// Problem is here
            EditText wNumbers =(EditText)findViewById(R.id.w_number_edit_text);
            String wNumber = wNumbers.getText().toString();
            Toast.makeText(getActivity(), wNumber, Toast.LENGTH_LONG).show();

        }
    }

    }

我的activity_main.xml

  <FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/container"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.example.medrec.MainActivity"
    tools:ignore="MergeRootFrame" />

我的fragment_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"
    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.medrec.MainActivity$PlaceholderFragment" >

    <EditText
        android:id="@+id/w_number_edit_text"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/textView1"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="21dp"
        android:ems="10"
        android:inputType="number" >

        <requestFocus />
    </EditText>

    <TextView
        android:id="@+id/textView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentTop="true"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="118dp"
        android:text="@string/w_number" />

    <Button
        android:id="@+id/w_login"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/w_number_edit_text"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="15dp"
        android:text="@string/w_login_text" />
 </RelativeLayout>

Answer 1

你应该改变这个

 EditText wNumbers =(EditText)findViewById(R.id.w_number_edit_text);

使用

EditText wNumbers =(EditText)rootview.findViewById(R.id.w_number_edit_text);

和onCreateView(......)如下所示：

 EditText wNumbers
 @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        View rootView = inflater.inflate(R.layout.fragment_main, container, false);

        Button login = (Button)rootView.findViewById(R.id.w_login);
        wNumbers =(EditText)rootView.findViewById(R.id.w_number_edit_text);
        login.setOnClickListener(new OnClickListener(){

    @Override
    public void onClick(View arg0) {
        // TODO Auto-generated method stub

    String wNumber = wNumbers.getText().toString();
    Toast.makeText(getActivity(), wNumber, Toast.LENGTH_LONG).show();
       }

    });
        return rootView;
    }

Answer 2

在EditText上初始化onCreateView： -

public static class PlaceholderFragment extends Fragment implements OnClickListener{

        public PlaceholderFragment() 
        {
        }

        EditText wNumbers 
        @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container,
                Bundle savedInstanceState) {
            View rootView = inflater.inflate(R.layout.fragment_main, container, false);

            wNumbers =(EditText)rootView.findViewById(R.id.w_number_edit_text);
            Button login = (Button)rootView.findViewById(R.id.w_login);
            login.setOnClickListener(new OnClickListener()
            {
                 @Override
                 public void onClick(View v)
                 {
                        // TODO Auto-generated method stub

                         String wNumber = wNumbers.getText().toString();
                         Toast.makeText(getActivity(), wNumber, Toast.LENGTH_LONG).show();
                 }
           });
            return rootView;
        }


 }

Answer 3

试试这个..

您无法在this Fragment内使用getActivity()

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

        Button login = (Button)rootView.findViewById(R.id.w_login);
        login.setOnClickListener(new OnClickListener(){

        @Override
        public void onClick(View arg0) {
            // TODO Auto-generated method stub

        EditText wNumbers =(EditText)rootView.findViewById(R.id.w_number_edit_text);
        String wNumber = wNumbers.getText().toString();
        Toast.makeText(getActivity(), wNumber, Toast.LENGTH_LONG).show();
        }

        });

        return rootView;
    }

Answer 4

在班级中定义rootview。并使用下面的EditText检测您的rootView.findviewbyid，

EditText wNumbers =(EditText)rootView.findViewById(R.id.w_number_edit_text);

onCreateView()代码如下，

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

                Button login = (Button)rootView.findViewById(R.id.w_login);
                login.setOnClickListener(this);
                return rootView;
            }

            @Override
            public void onClick(View v) {
                //////////////////////////// Problem is here
                EditText wNumbers =(EditText)rootView.findViewById(R.id.w_number_edit_text);
                String wNumber = wNumbers.getText().toString();
                Toast.makeText(getActivity(), wNumber, Toast.LENGTH_LONG).show();

            }

Android EditText在onclick方法上给出错误

4 个答案: