Android 同一活动中的两个片段 [英] Android Two Fragments in Same Activity

问题描述

我知道以下帖子:在单个活动中使用多个片段

我正在寻找的是针对特定问题的特定答案.以下代码的结果是一个空白的 FragmentActivity.我在下面的代码中缺少什么来让它呈现带有两个片段的活动.一个是空列表片段，另一个是包含一个输入框和一个水平布局按钮的片段，(这个布局可以在 http://developer.android.com/training/basics/firstapp/starting-activity.html) 我想绝对放在屏幕底部固定高度约25d.

What I am looking for is a specific answer to a specific problem. The result of the following code is a blank FragmentActivity. What am I missing in my following code to get it to render an activity with two fragments. One is a empty list fragment, the other is a fragment which contains a input box and a button in a horizontal layout, (this layout can be found at http://developer.android.com/training/basics/firstapp/starting-activity.html) that I want to be placed absolutely at the bottom of the screen with a fixed height of about 25 dip.

Manifest.xml

Manifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.my.package"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="17" />

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name="com.my.package.Application"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

我的主要活动及其相关的 application.xml 文件.

My main activity and its associated application.xml file.

package com.my.package;

import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.FragmentTransaction;

public class Application  
extends FragmentActivity 
implements MessageListViewFragment.OnLineSelectedListener, 
SendMessageFragment.OnSendButtonPressed {

    MessageListViewFragment mMessageListFragment;
    SendMessageFragment mSendMessageFragment;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.application);

        mMessageListFragment = new MessageListViewFragment();
        mSendMessageFragment = new SendMessageFragment();

        FragmentTransaction transaction = 
                getSupportFragmentManager().beginTransaction();

        transaction.add(R.id.message_fragment, mMessageListFragment);
        transaction.add(R.id.send_fragment, mSendMessageFragment);

        transaction.commit();
    }

    @Override
    public void onListItemSelected(int position) {
        // TODO Auto-generated method stub

    }

    @Override
    public void onSendButtonPressed() {
        // TODO Auto-generated method stub

    }
}

布局:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:baselineAligned="false"
    android:orientation="vertical" >

    <fragment
        android:id="@+id/message_fragment"
        android:name="com.example.android.fragments.MessageListViewFragment"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:gravity="top" />

    <fragment
        android:id="@+id/send_fragment"
        android:name="com.example.android.fragments.SendMessageFragment"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:gravity="bottom" />

</LinearLayout>

现在对于两个片段及其相关的 xml 文件:第一个片段(在顶部列出片段)

And now for the two fragments and their associated xml files: First Fragment (list fragment at top)

package com.my.package;

import android.app.Activity;
import android.os.Bundle;
import android.support.v4.app.ListFragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

public class MessageListViewFragment extends ListFragment {
    OnLineSelectedListener mCallback;

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

        // This makes sure that the container activity has implemented
        // the callback interface. If not, it throws an exception
        try {
            mCallback = (OnLineSelectedListener)activity;
        } catch (ClassCastException e) {
            throw new ClassCastException(activity.toString()
                    + " must implement OnLineSelectedListener");
        }
    }

    // Container Activity must implement this interface
    public interface OnLineSelectedListener {
        public void onListItemSelected(int position);
    }

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

    @Override
    public View onCreateView(LayoutInflater inflater, 
            ViewGroup container, Bundle savedInstanceState) {

        return inflater.inflate(R.layout.list_fragment, null);
    }
}

布局:

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/fragment_container"
    android:layout_width="match_parent"
    android:layout_height="match_parent" />

第二个片段(底部)

package com.my.package;

import android.app.Activity;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

public class SendMessageFragment extends Fragment {
    OnSendButtonPressed mCallback;

    // Container Activity must implement this interface
    public interface OnSendButtonPressed {
        public void onSendButtonPressed();
    }

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

    @Override
    public View onCreateView(LayoutInflater inflater, 
            ViewGroup container, Bundle savedInstanceState) {

        return inflater.inflate(R.layout.input_fragment, null);
    }

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

        // This makes sure that the container activity has implemented
        // the callback interface. If not, it throws an exception
        try {
            mCallback = (OnSendButtonPressed)activity;
        } catch (ClassCastException e) {
            throw new ClassCastException(activity.toString()
                    + " must implement OnHeadlineSelectedListener");
        }
    }
}

布局:

<LinearLayout 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:orientation="horizontal">
    <EditText android:id="@+id/edit_message"
        android:layout_weight="1"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:hint="@string/edit_message" />
    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/button_send" />
</LinearLayout>

推荐答案

执行以下操作:

1. 将主活动 XML 中的 Fragment 更改为 FrameLayout，两者都适用.
2. 将 layout_width 从 fill_parent 更改为 match_parent，对于主 XML 文件中的 FrameLayout，(创建的在第 1 步).
3. 将 layout_height 从 fill_parent 更改为 wrap_content，对于主 XML 文件中的 FrameLayout，(创建的在第 1 步).
4. 将 List Fragment XML 中的 FrameLayout 更改为 ListView，因为它是一个列表.
5. 把这个LisView的id改成@android:id/list，因为ListFragment需要它.

1. Change Fragment to FrameLayout in the main activity XML, for both.
2. Change layout_width from fill_parent to match_parent, for both FrameLayout in the main XML file, (ones created in step 1).
3. Change layout_height from fill_parent to wrap_content, for both FrameLayout in the main XML file, (ones created in step 1).
4. Change FrameLayout to ListView in the List Fragment XML because it is a List.
5. Change the id of this LisView to @android:id/list, because it is needed for the ListFragment.

然后告诉我，干杯.

编辑，还有这些:

1. 将return inflater.inflate(R.layout.list_fragment, null);改为return inflater.inflate(R.layout.list_fragment, container, false);.
2. 将return inflater.inflate(R.layout.input_fragment, null);改为return inflater.inflate(R.layout.input_fragment, container, false);

像这样制作您的主要活动 XML 文件:

Make your main activity XML file like this:

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >

    <FrameLayout
        android:id="@+id/message_fragment"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />

    <FrameLayout
        android:id="@+id/send_fragment"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true" />

</RelativeLayout>

我取出了 android:name"..." 因为我不知道那是什么，也无法找出它是什么，如果您确定知道它的作用，只需加回来，应该没问题.

I took out the android:name"..." because I don't know what that is nor able to find out what it is, if you know what it does for sure, just add it back, should be okay.

这篇关于Android 同一活动中的两个片段的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！