android - 如何访问android中 fragment 内的 Activity View 组件

Question

我的 Activity 中有一个编辑文本，我想检查该编辑文本是否为空 fragment 。谁能告诉我如何从 android 中的 fragment 访问 Activity 中存在的编辑 TextView 组件。我已经这样做了，但没有用。这是我的 Activity :

   package com.developer.mainandroid;


import android.widget.EditText;
import com.milan.tabs.pagerslidingstrip.PagerSlidingTabStrip;
import com.milan.validation.lib.RegExpressionValueValidator;
import com.milan.validation.lib.ValidationManager;

import android.app.ActionBar;
import android.app.SearchManager;
import android.content.Context;
import android.content.Intent;
import android.graphics.Color;
import android.graphics.drawable.ColorDrawable;
import android.os.Bundle;
import android.os.Handler;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
import android.support.v4.view.ViewPager;
import android.support.v4.view.ViewPager.OnPageChangeListener;
import android.support.v7.widget.SearchView;
import android.text.InputType;
import android.util.TypedValue;
import android.view.Gravity;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.View;
import android.widget.TextView;



public class Manual extends FragmentActivity  {
    private final Handler handler = new Handler();
    private PagerSlidingTabStrip tabs_sliding_strip;
    private ViewPager pager;
    private Tests adapter_tests;
    TextView welcome_headder;
    String welcome_headder_string;
    public EditText search_edit_text;

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

        ActionBar actionbar;
        actionbar = getActionBar();
        ColorDrawable color_action_bar = new ColorDrawable();
        color_action_bar.setColor(Color.parseColor("#673AB7"));
        actionbar.setBackgroundDrawable(color_action_bar);  
        search_edit_text = (EditText)findViewById(R.id.edt_number);
        search_edit_text.setInputType(InputType.TYPE_CLASS_NUMBER);
        search_edit_text.setGravity(Gravity.CENTER);
        search_edit_text.setCursorVisible(false);
        search_edit_text.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {
                search_edit_text.setCursorVisible(true);

            }
        });

        tabs_sliding_strip = (PagerSlidingTabStrip)findViewById(R.id.pager_sliding_tab_strip);
        pager = (ViewPager)findViewById(R.id.pager);
        adapter_tests = new Tests(getSupportFragmentManager());
        pager.setAdapter(adapter_tests);
        final int page_margin = (int)TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, 4, getResources().getDisplayMetrics());
        pager.setPageMargin(page_margin);
        tabs_sliding_strip.setTextColor(Color.parseColor("#FFFFFF"));
        tabs_sliding_strip.setTabActiveTextColor(Color.parseColor("#673AB7"), Color.parseColor("#FFFFFF"));
        tabs_sliding_strip.setViewPager(pager);
       // tabs_sliding_strip.setTextColor(Color.parseColor("#FF00FF"));


    }



    public class Tests extends FragmentPagerAdapter{

        private final String[] tests_types = {"BEFORE CONNECTING FUSE","AFTER CONNECTING FUSE","PISTON","FINAL AMMUNITATION"};

        public Tests(FragmentManager fm) {
            super(fm);
            // TODO Auto-generated constructor stub
        }
        @Override
        public CharSequence getPageTitle(int position) {
            return tests_types[position];
        }

        @Override
        public int getCount() {
            // TODO Auto-generated method stub
            return tests_types.length;
        }
        @Override
        public Fragment getItem(int position) {
            switch (position) {
            case 0:
                return new ManualMode_BC_Fuse_ckt();
            case 1:
                return new Manual_AC_Fuse_ckt();
            case 2:
                return new piston();
            case 3:
                return new Manualmode_final();
            }
            return new ManualMode_BC_Fuse_ckt();
        }

    }

这是我的 fragment Activity :

包 com.developer.mainandroid;

import com.milan.material.widget.FloatingEditText;
import com.milan.validation.lib.RegExpressionValueValidator;
import com.milan.validation.lib.ValidationManager;
import android.app.Activity;
import android.app.AlertDialog;
import android.app.Dialog;
import android.app.ProgressDialog;
import android.app.AlertDialog.Builder;
import android.graphics.Color;
import android.support.v4.app.DialogFragment;
import android.support.v4.app.Fragment;
import android.view.ContextMenu;
import android.view.ContextMenu.ContextMenuInfo;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.view.Window;
import android.widget.TextView;
import android.widget.Toast;
public class Manual_AC_Fuse_ckt extends Fragment {

    Manual manual_child;
    static FloatingEditText number_edit_text;
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        Root_view = inflater.inflate(R.layout.manualmode_ac_fuse_ckt, null);
         manual_child = new Manual();
        number_edit_text = (FloatingEditText)getActivity().findViewById(R.id.edt_number);

        registerForContextMenu(table_fuse_afer_cnc);
        return Root_view;
    }
    @Override
    public void onCreateContextMenu(ContextMenu menu, View v,
            ContextMenuInfo menuInfo) {
        menu.setHeaderTitle("MANUAL MODE : AFTER FUSE CONNECTION");
        menu.add(1, v.getId(), 0, "TEST  ");
        menu.add(1, v.getId(), 0, "SELECT ALL  ");
        menu.add(1, v.getId(), 0, "DESELECT ALL  ");
        super.onCreateContextMenu(menu, v, menuInfo);
    }
    @Override
    public boolean onContextItemSelected(MenuItem item) {
        if(item.getTitle()=="TEST  ")
        {
            if(manual_child.search_edit_text.equals(""))
            {
                Toast.makeText(getActivity(), "Please enter number", Toast.LENGTH_LONG).show();

            }
            else{

            //Do some operations

            }
        else if(item.getTitle()=="SELECT ALL  ")
        {

        }
        else if(item.getTitle()=="DESELECT ALL  ")
        {

        }

        return super.onContextItemSelected(item);
    }
    @Override
    public void onAttach(Activity activity) {
        super.onAttach(activity);
        if(activity.getClass()==Manual.class){
            manual_child = (Manual)activity;
        }
    }
    }

这是我的 Logcat:

01-02 03:07:43.170: E/AndroidRuntime(13424): FATAL EXCEPTION: main
01-02 03:07:43.170: E/AndroidRuntime(13424): java.lang.NullPointerException
01-02 03:07:43.170: E/AndroidRuntime(13424):    at android.app.Activity.findViewById(Activity.java:1853)
01-02 03:07:43.170: E/AndroidRuntime(13424):    at com.developer.mainandroid.Manual_AC_Fuse_ckt.onCreateView(Manual_AC_Fuse_ckt.java:74)
01-02 03:07:43.170: E/AndroidRuntime(13424):    at android.support.v4.app.Fragment.performCreateView(Fragment.java:1786)
01-02 03:07:43.170: E/AndroidRuntime(13424):    at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:953)
01-02 03:07:43.170: E/AndroidRuntime(13424):    at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1136)
01-02 03:07:43.170: E/AndroidRuntime(13424):    at android.support.v4.app.BackStackRecord.run(BackStackRecord.java:739)
01-02 03:07:43.170: E/AndroidRuntime(13424):    at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1499)
01-02 03:07:43.170: E/AndroidRuntime(13424):    at android.support.v4.app.FragmentManagerImpl.executePendingTransactions(FragmentManager.java:488)
01-02 03:07:43.170: E/AndroidRuntime(13424):    at android.support.v4.app.FragmentPagerAdapter.finishUpdate(FragmentPagerAdapter.java:141)
01-02 03:07:43.170: E/AndroidRuntime(13424):    at android.support.v4.view.ViewPager.populate(ViewPager.java:1073)
01-02 03:07:43.170: E/AndroidRuntime(13424):    at android.support.v4.view.ViewPager.populate(ViewPager.java:919)
01-02 03:07:43.170: E/AndroidRuntime(13424):    at android.support.v4.view.ViewPager.onMeasure(ViewPager.java:1441)
01-02 03:07:43.170: E/AndroidRuntime(13424):    at android.view.View.measure(View.java:15848)
01-02 03:07:43.170: E/AndroidRuntime(13424):    at android.widget.RelativeLayout.measureChildHorizontal(RelativeLayout.java:728)
01-02 03:07:43.170: E/AndroidRuntime(13424):    at android.widget.RelativeLayout.onMeasure(RelativeLayout.java:477)
01-02 03:07:43.170: E/AndroidRuntime(13424):    at android.view.View.measure(View.java:15848)
01-02 03:07:43.170: E/AndroidRuntime(13424):    at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5012)
01-02 03:07:43.170: E/AndroidRuntime(13424):    at android.widget.FrameLayout.onMeasure(FrameLayout.java:310)
01-02 03:07:43.170: E/AndroidRuntime(13424):    at android.view.View.measure(View.java:15848)
01-02 03:07:43.170: E/AndroidRuntime(13424):    at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5012)
01-02 03:07:43.170: E/AndroidRuntime(13424):    at com.android.internal.widget.ActionBarOverlayLayout.onMeasure(ActionBarOverlayLayout.java:302)
01-02 03:07:43.170: E/AndroidRuntime(13424):    at android.view.View.measure(View.java:15848)
01-02 03:07:43.170: E/AndroidRuntime(13424):    at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5012)
01-02 03:07:43.170: E/AndroidRuntime(13424):    at android.widget.FrameLayout.onMeasure(FrameLayout.java:310)
01-02 03:07:43.170: E/AndroidRuntime(13424):    at com.android.internal.policy.impl.PhoneWindow$DecorView.onMeasure(PhoneWindow.java:2189)
01-02 03:07:43.170: E/AndroidRuntime(13424):    at android.view.View.measure(View.java:15848)
01-02 03:07:43.170: E/AndroidRuntime(13424):    at android.view.ViewRootImpl.performMeasure(ViewRootImpl.java:1905)
01-02 03:07:43.170: E/AndroidRuntime(13424):    at android.view.ViewRootImpl.measureHierarchy(ViewRootImpl.java:1104)
01-02 03:07:43.170: E/AndroidRuntime(13424):    at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1284)
01-02 03:07:43.170: E/AndroidRuntime(13424):    at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1004)
01-02 03:07:43.170: E/AndroidRuntime(13424):    at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:5481)
01-02 03:07:43.170: E/AndroidRuntime(13424):    at android.view.Choreographer$CallbackRecord.run(Choreographer.java:749)
01-02 03:07:43.170: E/AndroidRuntime(13424):    at android.view.Choreographer.doCallbacks(Choreographer.java:562)
01-02 03:07:43.170: E/AndroidRuntime(13424):    at android.view.Choreographer.doFrame(Choreographer.java:532)
01-02 03:07:43.170: E/AndroidRuntime(13424):    at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:735)
01-02 03:07:43.170: E/AndroidRuntime(13424):    at android.os.Handler.handleCallback(Handler.java:730)
01-02 03:07:43.170: E/AndroidRuntime(13424):    at android.os.Handler.dispatchMessage(Handler.java:92)
01-02 03:07:43.170: E/AndroidRuntime(13424):    at android.os.Looper.loop(Looper.java:137)
01-02 03:07:43.170: E/AndroidRuntime(13424):    at android.app.ActivityThread.main(ActivityThread.java:5103)
01-02 03:07:43.170: E/AndroidRuntime(13424):    at java.lang.reflect.Method.invokeNative(Native Method)
01-02 03:07:43.170: E/AndroidRuntime(13424):    at java.lang.reflect.Method.invoke(Method.java:525)
01-02 03:07:43.170: E/AndroidRuntime(13424):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737)
01-02 03:07:43.170: E/AndroidRuntime(13424):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
01-02 03:07:43.170: E/AndroidRuntime(13424):    at dalvik.system.NativeStart.main(Native Method)

Answer 1

使用

EditText  editText =  getActivity().findViewById(R.id.EditText);