ViewPager简单用法

这里讲述一个入门级别的ViewPager用于页面切换的例子。

页面有点朴素，这里将聚焦于ViewPager的基本用法。

ViewPager用于页面切换

1. 定义ScreenSlidePageFragment

<!-- fragment_screen_slide_page.xml -->
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android" android:id="@+id/content" android:layout_width="match_parent" android:layout_height="match_parent" >

    <TextView style="?android:textAppearanceMedium" android:padding="16dp" android:lineSpacingMultiplier="1.2" android:layout_width="match_parent" android:layout_height="wrap_content" android:text="@string/app_name" />
</ScrollView>

package com.hang.viewpagerdemo;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

public class ScreenSlidePageFragment extends Fragment {

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

        return rootView;
    }
}

1. 定义ScreenSlidePagerAdapter

package com.hang.viewpagerdemo;

import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentStatePagerAdapter;

/** * A simple pager adapter that represents 5 ScreenSlidePageFragment objects, in * sequence. */
public class ScreenSlidePagerAdapter extends FragmentStatePagerAdapter {
    /** * The number of pages (wizard steps) to show in this demo. */
    private static final int NUM_PAGES = 5;

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

    @Override
    public Fragment getItem(int position) {
        return new ScreenSlidePageFragment();
    }

    @Override
    public int getCount() {
        return NUM_PAGES;
    }
}

1. 定义MainActivity展示

<!--activity_main.xml-->
<android.support.v4.view.ViewPager xmlns:android="http://schemas.android.com/apk/res/android" android:id="@+id/pager" android:layout_width="match_parent" android:layout_height="match_parent" />

package com.hang.viewpagerdemo;

import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
import android.support.v4.view.PagerAdapter;
import android.support.v4.view.ViewPager;

public class MainActivity extends FragmentActivity {

    /** * The pager widget, which handles animation and allows swiping horizontally to access previous * and next wizard steps. */
    private ViewPager mPager;

    /** * The pager adapter, which provides the pages to the view pager widget. */
    private PagerAdapter mPagerAdapter;

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

        // Instantiate a ViewPager and a PagerAdapter.
        mPager = (ViewPager) findViewById(R.id.pager);
        mPagerAdapter = new ScreenSlidePagerAdapter(getSupportFragmentManager());
        mPager.setAdapter(mPagerAdapter);
    }

    @Override
    public void onBackPressed() {
        if (mPager.getCurrentItem() == 0) {
            // If the user is currently looking at the first step, allow the system to handle the
            // Back button. This calls finish() on this activity and pops the back stack.
            super.onBackPressed();
        } else {
            // Otherwise, select the previous step.
            mPager.setCurrentItem(mPager.getCurrentItem() - 1);
        }
    }


}

到这里，让我想到ViewPager和listview是如此类似！

翻译地址

https://developer.android.com/training/animation/screen-slide.html#pagetransformer