Android support library View Pages: custom style and layout
Android support library View Pages: custom style and layout
introduction:
The Android support library provides many useful components and tools, one of which is ViewPager.ViewPage is a view component that can slide multiple pages, which is very suitable for achieving navigation pages, pictures and other functions.In this article, we will introduce how to customize the appearance and behavior of ViewPager through custom style and layout.
1. Create ViewPager layout file
First of all, we need to create a layout file to define the appearance and structure of ViewPager.The following is a simple example:
<androidx.viewpager.widget.ViewPager
android:id="@+id/viewPager"
android:layout_width="match_parent"
android:layout_height="match_parent" />
In this layout file, we created a ViewPager with an ID "ViewPager", setting the width and height to the match_parent to fill the entire parent container.
2. Create a custom page layout
Next, we need to create a custom page layout for ViewPager.The style and content of the page can be designed according to the actual needs.The following is an example:
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<ImageView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:src="@drawable/image1" />
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Page 1" />
</LinearLayout>
In this example layout, we created a vertical linear layout containing an ImageView and a TextView.ImageView shows a picture, the title of the textView display page.
3. Create custom Pageradapter
When using ViewPager, you need to use a Pageradapter to provide the content of the page.We can create a custom Pageradapter to load the page layout we previously defined.The following is a simple example:
public class CustomPagerAdapter extends PagerAdapter {
private LayoutInflater inflater;
public CustomPagerAdapter(Context context) {
inflater = LayoutInflater.from(context);
}
@Override
public int getCount() {
Return 3; // Return to the total page number
}
@Override
public boolean isViewFromObject(View view, Object object) {
return view == object;
}
@Override
public Object instantiateItem(ViewGroup container, int position) {
// Load the custom page layout
View view = inflater.inflate(R.layout.custom_page_layout, container, false);
// You can set the page content as needed
container.addView (view); // Add the page to the container
return view;
}
@Override
public void destroyItem(ViewGroup container, int position, Object object) {
container.removeView ((view) object); // destroy the page
}
}
In this custom Pageradapter, we have rewritten a few methods to achieve loading custom page layout.In the InstantiatedItem method, we loaded the previously defined page layout through Layoutinflator and added it to the container of the ViewPager.In the Destroyitem method, we remove the page layout in our veteran to destroy the page.
4. Set customized pageradapter
The last step is to set our custom Pageradapter to ViewPager.You can complete this operation in the code, as shown below:
ViewPager viewPager = findViewById(R.id.viewPager);
CustomPagerAdapter adapter = new CustomPagerAdapter(this);
viewPager.setAdapter(adapter);
In this example, we found the previously created ViewPager and created a CustomPageradapter instance.Then set the adapter to ViewPager so that it can display the custom page layout.
in conclusion:
By custom style and layout, we can customize the ViewPager in the Android support library to make it have various appearances and behaviors.We can create a custom page layout and use the custom Pageradapter to load the page content.This enables us to create personalized ViewPager components with personalized characteristics.
