问题描述

I have 12 items in android sliding tab layout + view pager. While sliding from left to right, selected tab should be center same as play store. Please help me how to do that. In my application active tab is always left of the screen.

My approach differs a bit of the Shripad Bhat solution, which bounce the tab at the end of the slide.

Here's my workaround...

Changes to onPageScrolled method:

@Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
    int tabStripChildCount = mTabStrip.getChildCount();
    if ((tabStripChildCount == 0) || (position < 0) || (position >= tabStripChildCount)) {
        return;
    }

    mTabStrip.onViewPagerPageChanged(position, positionOffset);

    View selectedTitle = mTabStrip.getChildAt(position);
    int selectedOffset = (selectedTitle == null) ? 0 : selectedTitle.getWidth();
    int nextTitlePosition = position + 1;
    View nextTitle = mTabStrip.getChildAt(nextTitlePosition);
    int nextOffset = (nextTitle == null) ? 0 : nextTitle.getWidth();
    int extraOffset = (int)(0.5F * (positionOffset * (float)(selectedOffset + nextOffset)));
    scrollToTab(position, extraOffset);

    if (mViewPagerPageChangeListener != null) {
        mViewPagerPageChangeListener.onPageScrolled(position, positionOffset, positionOffsetPixels);
    }
}

Changes to scrollToTab method:

private int mLastScrollTo;

private void scrollToTab(int tabIndex, int positionOffset) {
    final int tabStripChildCount = mTabStrip.getChildCount();
    if (tabStripChildCount == 0 || tabIndex < 0 || tabIndex >= tabStripChildCount) {
        return;
    }

    View selectedChild = mTabStrip.getChildAt(tabIndex);
    if (selectedChild != null && selectedChild.getMeasuredWidth() != 0) {

        int targetScrollX = ((positionOffset + selectedChild.getLeft()) - getWidth() / 2) + selectedChild.getWidth() / 2;

        if (targetScrollX != mLastScrollTo) {
            scrollTo(targetScrollX, 0);
            mLastScrollTo = targetScrollX;
        }
    }
}

这篇关于如何在android滑动选项卡布局中对齐活动选项卡中心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编程学习网！