如何实现显示上一页和下一页以及重点突出的页面的ViewPager

问题描述

我正在尝试创建一些东西，使其在viewpager上显示我的页面，以使其具有良好的感觉和设计，我检查了此，它在某种程度上有所帮助，并遵循了 link 关于如何实现它，但最终遇到了一些问题.首先，对于在API11以下运行的设备(API8是我的目标)，它将无法正常工作或看起来效果不佳.其次，我无法使重点页面比下一页和上一页大.为了设计，我希望它看起来像这样:

I'm trying to create something that will display my pages on a viewpager for it to have nice feel and design and I checked out this link which somehow helps and also follow this link on how I can implement it but I ended up with some issues. First is that it won't really work or look that good for devices that runs below API11 (API8 is my target). and Second is that I can't manage to make the focused page to be bigger than the next and previous page. I wanted it look something like this for the sake of design:

希望有人可以在此方面或其他任何方式上帮助我.

Hope someone can help me on this or any other way to achieve this.

推荐答案

阅读首先.然后应用您自己的PageTransformer实现.像这样:

Read this first. Then apply your own PageTransformer implementation. Something like this:

public class DepthPageTransformer implements ViewPager.PageTransformer {
    private static final float MIN_SCALE = 0.5f;
    private static final float MAX_SCALE = 0.8f;
    private static final float MIN_FADE = 0.2f;

    public void transformPage(View view, float position) {
        int pageWidth = view.getWidth();

        if (position < -1) {
            view.setAlpha(MIN_FADE);
        } else if (position < 0) {
            view.setAlpha(1 + position * (1 - MIN_FADE));
            view.setTranslationX(-pageWidth * MAX_SCALE * position);
            ViewCompat.setTranslationZ(view, position);
            float scaleFactor = MIN_SCALE
                    + (MAX_SCALE - MIN_SCALE) * (1 - Math.abs(position));
            view.setScaleX(scaleFactor);
            view.setScaleY(scaleFactor);
        } else if (position == 0) {
            view.setAlpha(1);
            view.setTranslationX(0);
            view.setScaleX(MAX_SCALE);
            ViewCompat.setTranslationZ(view, 0);
            view.setScaleY(MAX_SCALE);
        } else if (position <= 1) {
            ViewCompat.setTranslationZ(view, -position);
            view.setAlpha(1 - position * (1 - MIN_FADE));
            view.setTranslationX(pageWidth * MAX_SCALE * -position);

            float scaleFactor = MIN_SCALE
                    + (MAX_SCALE - MIN_SCALE) * (1 - Math.abs(position));
            view.setScaleX(scaleFactor);
            view.setScaleY(scaleFactor);
        } else {
            view.setAlpha(MIN_FADE);
        }
    }
}

您还需要控制子绘制顺序以将当前选定的视图设置在顶部(仅在您的视图彼此重叠时才需要):

You will also need to control the child drawing order to set the current selected View on top (only needed, if your views overlay each other):

public class MyPager extends ViewPager {
    public MyPager(Context context) {
        this(context, null);
    }

    public MyPager(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    @Override
    protected int getChildDrawingOrder(int childCount, int i) {
        if(i == childCount - 1) {
            return getCurrentItem();
        } else {
            return i >= getCurrentItem()? i + 1 : i;
        }
    }
}

如果屏幕上有更多可见的页面，请将ViewPager.setOffscreenPageLimit设置为2或更大.

Set ViewPager.setOffscreenPageLimit to 2 or even more, if you have more visible pages on screen.

这是结果:

这篇关于如何实现显示上一页和下一页以及重点突出的页面的ViewPager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！