Question

我一直在搜索Stack Overflow，但似乎无法找到有关此问题的有用信息。下面我附上了我的Home Activity的代码，以及它的XML文件。我似乎无法理解问题所在，我不知道我做错了什么。我想展示第三类的内容（例如，我的每个片段的不同片段类，基本上我希望能够在家庭活动中显示同一片段持有者中的所有片段..在这种情况下我正在尝试打开片段Bookmarks（men.bookmarks）..

有什么建议吗？

我没有包含片段的代码，因为它会有很多类，但如果你需要它，请告诉我:) ..

XML file for my HomeActivity:
<?xml version="1.0" encoding="utf-8"?> <android.support.v4.widget.DrawerLayout 
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/drawer_layout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true"
tools:openDrawer="start" >


<include
    layout="@layout/app_bar_home"
    android:layout_width="match_parent"
    android:layout_height="match_parent"/>

<android.support.design.widget.NavigationView
    android:id="@+id/nav_view"
    android:layout_width="wrap_content"
    android:layout_height="match_parent"
    android:layout_gravity="start"
    android:fitsSystemWindows="true"
    app:headerLayout="@layout/nav_header_home"
    app:menu="@menu/activity_home_drawer" />

<fragment
    android:name="com.nooriandroid.n007.mybookmarks_v1.Fragment_Bookmarks"
    android:id="@+id/fragBookmarks"
    android:layout_weight="2"
    android:layout_width="25dp"
    android:layout_height="match_parent" />

</android.support.v4.widget.DrawerLayout>

    package com.nooriandroid.n007.mybookmarks_v1;
    import android.app.Fragment;
    import android.app.FragmentManager;
    import android.app.FragmentTransaction;
    import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.NavigationView;
import android.support.design.widget.Snackbar;
import android.support.v4.view.GravityCompat;
import android.support.v4.widget.DrawerLayout;
import android.support.v7.app.ActionBar;
import android.support.v7.app.ActionBarDrawerToggle;
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 android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toast;
import java.io.File;
import java.text.SimpleDateFormat;
import java.util.Date;

public class Activity_Home extends AppCompatActivity implements NavigationView.OnNavigationItemSelectedListener {

    //--------------Variables---------------------//
    private String date_pattern = "hh:mm dd-MM-yyyy";
    private Fragment fragment_bookmarks;
    private Fragment_Favorite fragment_favorite;
    private Fragment_Category fragment_category;
    private Fragment_SharedWith_me fragment_sharedWith_me;
    private Fragment_Myshared fragment_myshared;
    private Activity_Home homeActivity;
    private Fragment_Item_Container fragment_item_container;

    private User user;
    private boolean frag_favorite_visible = false, frag_bookmark_visible = false, frag_category_visible = false,
            frag_myshared_visible = false, frag_sharedwithme__visible = false;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_home);
        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);
        FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
        fab.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
                        .setAction("Action", null).show();
            }
        });
        DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
        ActionBarDrawerToggle toggle = new ActionBarDrawerToggle(
                this, drawer, toolbar, R.string.navigation_drawer_open, R.string.navigation_drawer_close);
        drawer.setDrawerListener(toggle);
        toggle.syncState();
        NavigationView navigationView = (NavigationView) findViewById(R.id.nav_view);
        navigationView.setNavigationItemSelectedListener(this);

        //---------------Customized------------------//
        setTitle("Home");
        ActionBar ab = getSupportActionBar();
        ab.setLogo(R.mipmap.ic_logolight);
        ab.setDisplayUseLogoEnabled(true);
        ab.setDisplayShowHomeEnabled(true);

        fragment_favorite = new Fragment_Favorite();
        fragment_bookmarks = new Fragment_Bookmarks();
        fragment_category = new Fragment_Category();
        fragment_myshared = new Fragment_Myshared();
        fragment_sharedWith_me = new Fragment_SharedWith_me();
        fragment_item_container = new Fragment_Item_Container();
        homeActivity = this;

        FragmentManager fragmentManager = getFragmentManager();
        final FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
        fragmentTransaction.add(R.id.fragment_container, fragment_favorite);
        fragmentTransaction.add(R.id.fragment_container, fragment_bookmarks);
        fragmentTransaction.add(R.id.fragment_container, fragment_category);
        fragmentTransaction.add(R.id.fragment_container, fragment_myshared);
        fragmentTransaction.add(R.id.fragment_container, fragment_sharedWith_me);
        frag_favorite_visible = true;
        fragmentTransaction.hide(fragment_bookmarks);
        fragmentTransaction.hide(fragment_category);
        fragmentTransaction.hide(fragment_myshared);
        fragmentTransaction.hide(fragment_sharedWith_me);
        fragmentTransaction.commit();

        goHomeOnclicked();

        user = new User();
        user = (User) getIntent().getSerializableExtra("currentuser");
    }

    @Override
    public void onBackPressed() {
        DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
        if (drawer.isDrawerOpen(GravityCompat.START)) {
            drawer.closeDrawer(GravityCompat.START);
        } else {
            super.onBackPressed();
        }
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.home, menu);
        rundUserSettings();
        SimpleDateFormat format = new SimpleDateFormat(date_pattern);
        String current_date = format.format(new Date());

        TextView nav_textview_Date = (TextView) findViewById(R.id.textView_Date);
        nav_textview_Date.setText(current_date);
        TextView nameLast_textView = (TextView) findViewById(R.id.textView_UsernameLastname);
        nameLast_textView.setText("" + user.getName() + " " + user.getLast_name());

        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);
    }

    @SuppressWarnings("StatementWithEmptyBody")
    @Override
    public boolean onNavigationItemSelected(MenuItem item) {
        // Handle navigation view item clicks here.
        int id = item.getItemId();
        if (id == R.id.men_newItem) {
            Intent intent_NewItem = new Intent("com.nooriandroid.n007.mybookmarks_v1.Activity_NewItem");
            startActivity(intent_NewItem);

        } else if (id == R.id.men_bookmarks) {
            FragmentManager fragmentManager = getFragmentManager();
            FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
            checkFragmentsStatus(fragmentTransaction);
            fragmentTransaction.show(fragment_bookmarks);
            frag_bookmark_visible = true;
            this.setTitle("Bookmarks"); ///Ombytnings Zirt
            fragmentTransaction.commit(); ///


        } else if (id == R.id.men_category) {
            FragmentManager fragmentManager = getFragmentManager();
            FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
            checkFragmentsStatus(fragmentTransaction);
            frag_category_visible= true;
            fragmentTransaction.show(fragment_category);
            fragmentTransaction.commit();
            this.setTitle("Categories ");

            Toast.makeText(Activity_Home.this,"Not implemented yet.!",Toast.LENGTH_SHORT).show();
        }
         else if (id == R.id.men_share) {
            Toast.makeText(Activity_Home.this,"Not implemented yet.!",Toast.LENGTH_SHORT).show();

        } else if (id == R.id.men_sharedwithme) {
            FragmentManager fragmentManager = getFragmentManager();
            FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
            checkFragmentsStatus(fragmentTransaction);
            frag_sharedwithme__visible = true;
            fragmentTransaction.show(fragment_sharedWith_me);
            fragmentTransaction.commit();
            this.setTitle("Shared with me");
            Toast.makeText(Activity_Home.this,"Not implemented yet.!",Toast.LENGTH_SHORT).show();
        } else if (id == R.id.men_myshared) {
            FragmentManager fragmentManager = getFragmentManager();
            FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
            checkFragmentsStatus(fragmentTransaction);
            frag_myshared_visible = true;
            fragmentTransaction.show(fragment_myshared);
            fragmentTransaction.commit();
            this.setTitle("My shared");
            Toast.makeText(Activity_Home.this,"Not implemented yet.!",Toast.LENGTH_SHORT).show();
        }
        DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
        drawer.closeDrawer(GravityCompat.START);
        return true;
    }

    private void checkFragmentsStatus(FragmentTransaction fragmentTransaction){
        if (frag_favorite_visible){
            frag_favorite_visible = false;
            fragmentTransaction.hide(fragment_favorite);
        }else if (frag_bookmark_visible){
            frag_bookmark_visible = false;
            fragmentTransaction.hide(fragment_bookmarks);
        }else if (frag_category_visible){
            frag_category_visible = false;
            fragmentTransaction.hide(fragment_category);
        }else if (frag_myshared_visible){
            frag_myshared_visible = false;
            fragmentTransaction.hide(fragment_myshared);
        }else if (frag_sharedwithme__visible){
            frag_sharedwithme__visible = false;
            fragmentTransaction.hide(fragment_sharedWith_me);
        }
    }

    private void goHomeOnclicked(){
        findViewById(R.id.toolbar).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if (!frag_favorite_visible){
                    FragmentManager fragmentManager = getFragmentManager();
                    FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
                    checkFragmentsStatus(fragmentTransaction);
                    frag_favorite_visible = true;
                    fragmentTransaction.show(fragment_favorite);
                    fragmentTransaction.commit();
                    homeActivity.setTitle("Home");
                }
            }
        });
    }

    private boolean rundUserSettings(){
        if (this.user!=null){
            try {
                File file = new File(user.getProfile_pic());
                Uri uri = Uri.fromFile(file);
                ImageView view = (ImageView) findViewById(R.id.imageView_ProfilePic);
                view.setImageURI(uri);

            }catch (Exception e){
                Toast.makeText(Activity_Home.this,"Unable to load profile picture.!",Toast.LENGTH_SHORT).show();
            }
            return true;
        } else {
            return false;
        }
    }
    }

Answer 1

您用于在同一活动中添加不同片段的代码实际上已经搞砸了。你可以使用更好的方法。我在下面添加了示例代码：

在Activity的布局中，添加以下代码行

<FrameLayout
        android:id="@+id/fragBookmarks"
        android:layout_weight="2"
        android:layout_width="25dp"
        android:layout_height="match_parent" />

而不是：

<fragment
android:name="com.nooriandroid.n007.mybookmarks_v1.Fragment_Bookmarks"
android:id="@+id/fragBookmarks"
android:layout_weight="2"
android:layout_width="25dp"
android:layout_height="match_parent" />

现在在HomeActivity中编写此方法以添加不同的片段

public void addFragment(Fragment frag, String tag) {
    FragmentTransaction transaction = getFragmentManager().beginTransaction();
    transaction.replace(R.id.fragBookmarks, frag, tag);
    transaction.addToBackStack(getFragmentManager().getBackStackEntryCount() == 0 ? "FirstFragment" : null).commit();
    }
}

此方法可帮助您随时随地向此活动添加任何片段。您不需要从头开始添加所有片段。喜欢如果现在我在HomeFragment上，我想在Home上点击按钮打开BookmarkFragment，我会写类似的东西;

btnBookmark.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            ((HomeActivity) getActivity()).addFragment(new BookmarkFragment(), BookmarkFragment.class.getSimpleName()); // This will add the new fragment Bookmark fragment to the activity while adding it to backstack
        }
    });

现在，如果您想从BookmarkFragment返回到HomeFragment，请在HomeActivity中添加此方法

public void popFragment() {
    if (getFragmentManager() == null)
        return;
    getFragmentManager().popBackStack();
}

并在BookmarkFragment中调用此函数，例如

btnBack.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            ((HomeActivity) getActivity()).popFragment(); // This will remove the last added fragment Bookmark fragment
        }
    });

Answer 2

DrawerLayout应该只有两个直接子项。如果要在同一个活动中替换不同的片段，请在app_bar_home布局中创建一个FrameLayout。然后在Activity中，执行此操作以替换片段。

FragmentManager fragmentManager = getSupportFragmentManager();
FragmentTransaction transaction = fragmentManager.beginTransaction();
transaction.replace(R.id.frame_layout_id,new yourFragment()).commit();

在家庭活动中打开一个片段

2 个答案: