java - Material 设计与安卓工作室

Question

我的代码有一些问题..

我正在尝试使用 fragment 实现 Material 设计，但 fragment 未显示。

下图是它的外观。

Material Design

然而这是我得到的:

My App

XML 代码如下:

<android.support.design.widget.CoordinatorLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/main_content"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <android.support.v4.view.ViewPager
        android:id="@+id/viewpager"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        app:layout_behavior="@string/appbar_scrolling_view_behavior" />

    <android.support.design.widget.AppBarLayout
        android:id="@+id/appbar"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar">

        <android.support.v7.widget.Toolbar
            android:id="@+id/toolbar"
            android:layout_width="match_parent"
            android:layout_height="?attr/actionBarSize"
            android:background="?attr/colorPrimary"
            app:layout_scrollFlags="scroll|enterAlways"
            app:popupTheme="@style/ThemeOverlay.AppCompat.Light" />

        <android.support.design.widget.TabLayout
            android:id="@+id/tabs"
            android:layout_width="match_parent"
            android:layout_height="wrap_content" />


    </android.support.design.widget.AppBarLayout>

</android.support.design.widget.CoordinatorLayout>

MainActivity 下面

package com.example.adeel.liverpoolnewsapp;

import android.support.design.widget.TabLayout;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.Toolbar;

public class MainActivity_home extends AppCompatActivity {

@Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main_home);
        //adding toolbar
        Toolbar toolbar= (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);
        //adding tabs below
        TabLayout tabs = (TabLayout) findViewById(R.id.tabs);
        tabs.addTab(tabs.newTab().setText("Tab 1"));
        tabs.addTab(tabs.newTab().setText("Tab 2"));
        tabs.addTab(tabs.newTab().setText("Tab 3"));
    }
}

Answer 1

您必须使用选项卡布局设置 ViewPager。

看下面的方法和类:

private void setupViewPager(ViewPager viewPager) {
    ViewPageAdapter adapter = new ViewPagerAdapter(getSupportFragmentManager());
    adapter.addFragment(new FragmentName(), "TAB_TITLE");
    viewPager.setAdapter(adapter);

}

class ViewPagerAdapter extends FragmentPaferAdapter{
    private final List<Fragment> mFragmentList = new ArrayList<>();
    private final List<String> mFragmentTitleList = new ArrayList<>();

           public ViewPagerAdapter(FragmentManager manager) {
            super(manager);
        }

        @Override
        public Fragment getItem(int position) {
            return mFragmentList.get(position);
        }

        @Override
        public int getCount() {
            return mFragmentList.size();
        }

        public void addFragment(Fragment fragment, String title) {
            mFragmentList.add(fragment);
            mFragmentTitleList.add(title);
        }

        @Override
        public CharSequence getPageTitle(int position) {
            return mFragmentTitleList.get(position);
        }
} 

在您的 MainActivity 中这样使用:

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


    toolbar = (Toolbar) findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);

    getSupportActionBar().setDisplayHomeAsUpEnabled(true);

    viewPager = (ViewPager) findViewById(R.id.viewpager);
    setupViewPager(viewPager);

    tabLayout = (TabLayout) findViewById(R.id.tabs);
    tabLayout.setupWithViewPager(viewPager);
}

activity_main.xml :

<android.support.design.widget.AppBarLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar">

    <android.support.v7.widget.Toolbar
        android:id="@+id/toolbar"
        android:layout_width="match_parent"
        android:layout_height="?attr/actionBarSize"
        android:background="?attr/colorPrimary"
        app:layout_scrollFlags="scroll|enterAlways"
        app:popupTheme="@style/ThemeOverlay.AppCompat.Light" />

    <android.support.design.widget.TabLayout
        android:id="@+id/tabs"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        app:tabMode="fixed"
        app:tabGravity="fill"/>
</android.support.design.widget.AppBarLayout>

<android.support.v4.view.ViewPager
    android:id="@+id/viewpager"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    app:layout_behavior="@string/appbar_scrolling_view_behavior"  />

详情请看这里:

• Android Hive - Working with Tabs