Question

这是我的Menu java代码，其中包含滑动视图界面中的片段，其中我对每个片段都有单独的活动。我通过调用此活动遇到一个应用程序类，我希望有人可以帮助我解决我的问题，因为我是android编程的初学者。非常感谢您的帮助。

package com.example.lazynumber;

import java.util.Locale;

import android.annotation.SuppressLint;
import android.content.Intent;
import android.os.Bundle;
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.app.NavUtils;
import android.support.v4.view.ViewPager;
import android.view.Gravity;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.TextView;

public class MainMenu extends FragmentActivity {

/**
 * The {@link android.support.v4.view.PagerAdapter} that will provide
 * fragments for each of the sections. We use a
 * {@link android.support.v4.app.FragmentPagerAdapter} derivative, which
 * will keep every loaded fragment in memory. If this becomes too memory
 * intensive, it may be best to switch to a
 * {@link android.support.v4.app.FragmentStatePagerAdapter}.
 */
SectionsPagerAdapter mSectionsPagerAdapter;

/**
 * The {@link ViewPager} that will host the section contents.
 */
ViewPager mViewPager;

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

    // Create the adapter that will return a fragment for each of the three
    // primary sections of the app.
    mSectionsPagerAdapter = new SectionsPagerAdapter(
            getSupportFragmentManager());

    // Set up the ViewPager with the sections adapter.
    mViewPager = (ViewPager) findViewById(R.id.pager);
    mViewPager.setAdapter(mSectionsPagerAdapter);


}

@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, menu);
    return true;
}

/**
 * A {@link FragmentPagerAdapter} that returns a fragment corresponding to
 * one of the sections/tabs/pages.
 */
public class SectionsPagerAdapter extends FragmentPagerAdapter {

    public SectionsPagerAdapter(FragmentManager fm) {
        super(fm);
    }

    @Override
    public Fragment getItem(int position) {
        // getItem is called to instantiate the fragment for the given page.
        // Return a DummySectionFragment (defined as a static inner class
        // below) with the page number as its lone argument.
        switch(position){
        case 0:
            Fragment fragment = new GetNumberFragment();
            return fragment;

        case 1:
            Fragment fragment2 = new QRFragment();
            return fragment2;

        case 2:
            Fragment fragment3 = new ProfileFragment();
            return fragment3;

        default:
            return null;
        }
    }

    @Override
    public int getCount() {
        // Show 3 total pages.
        return 3;
    }

    @Override
    public CharSequence getPageTitle(int position) {
        Locale l = Locale.getDefault();
        switch (position) {
        case 0:
            return getString(R.string.title_section1).toUpperCase(l);
        case 1:
            return getString(R.string.title_section2).toUpperCase(l);
        case 2:
            return getString(R.string.title_section3).toUpperCase(l);
        }
        return null;
    }
}

/**
 * A dummy fragment representing a section of the app, but that simply
 * displays dummy text.
 */
public static class GetNumberFragment extends Fragment {
    /**
     * The fragment argument representing the section number for this
     * fragment.
     */
    public static final String ARG_SECTION_NUMBER = "section_number";

    public GetNumberFragment() {
    }

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


@SuppressLint("ValidFragment")
public class QRFragment extends Fragment{

    public QRFragment(){};

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState){
        View rootView2 = inflater.inflate(R.layout.qrintro, container, false);

        Button testingButton = (Button)findViewById(R.id.goinQRPay);
        testingButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                goTesting();
            }
        });
        return rootView2;
    }
}

private void goTesting(){
    Intent goTesting = new Intent(this, Testingbutton.class);
    startActivity(goTesting);
}

public static class ProfileFragment extends Fragment{

    public ProfileFragment(){}

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState){
        View rootView3 = inflater.inflate(R.layout.activity_profile_setting, container, false);
        return rootView3;
    }
}
}

如果需要，这些是我的xml代码供参考。第一个是mainmenu xml

<android.support.v4.view.ViewPager xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/pager"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainMenu" >

<!--
This title strip will display the currently visible page title, as well as the page
titles for adjacent pages.
-->

<android.support.v4.view.PagerTitleStrip
    android:id="@+id/pager_title_strip"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_gravity="top"
    android:background="#33b5e5"
    android:paddingBottom="4dp"
    android:paddingTop="4dp"
    android:textColor="#fff" />

</android.support.v4.view.ViewPager>

下一个xml是我需要有一个QRFragment活动xml接口的函数。

<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=".QRIntro" >

<ImageView 
    android:id="@+id/qrintropic"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_centerInParent="true"
    android:src="@drawable/qrlazy" />

<Button
    android:id="@+id/goinQRPay"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_below="@+id/qrintropic"
    android:layout_centerHorizontal="true"
    android:layout_marginTop="20dp"
    android:text="@string/buttontoqr" />"

</RelativeLayout>

Answer 1

片段需要像FrameLayout一样插入某种容器布局中。如果添加，则可以使用此方法替换片段

public static void replaceFragment(Activity activity, int containerlayoutId, Fragment newFragment) {
    FragmentTransaction transaction = activity.getFragmentManager().beginTransaction().replace(containerlayoutId, newFragment);
    transaction.commit();
    activity.getFragmentManager().executePendingTransactions();     
}

Android：片段代码导致应用程序崩溃

1 个答案: