问题描述

我有一个 ViewPager，我使用 switch 和 case 在片段之间移动.我可以更改每个位置的标题，但我也想更改每个位置的背景颜色.

I have a ViewPager, and I move between fragments using a switch and case. I can change the title per position, but I would also like to change the background colour per position.

public PagerTabStrip titleStrip;
    titleStrip.setBackgroundColor(Color.DKGRAY);

在我的 onCreateView 中使用它会设置一个永久的背景颜色.我的想法是使用 titleStrip.setBackgroundColor(Color.DKGRAY);我在哪里切换片段或更改标题.但它不能正常工作.有时颜色会改变，有时不会，有时会在错误的片段中改变.

Using this in my onCreateView sets a permanent background colour. The idea I had was to use the titleStrip.setBackgroundColor(Color.DKGRAY); where I switch the fragments or change the title. But it doesn't work properly. Sometimes the colour changes, sometimes it doesn't, sometimes it changes in the wrong fragment.

这是我切换片段的代码:

This is the code where I switch fragments:

@Override
    public Fragment getItem(int position) { 

        switch (position) {

        case 0:  titleStrip.setBackgroundColor(Color.DKGRAY); // These
                 titleStrip.setTextColor(Color.WHITE); // This doesn't work either

            return new Fragment0();

        case 1:
            return new Fragment1();
        case 2:
            return new Fragment3();
        }
        return null;
    }

推荐答案

首先，让你在createView时得到titleStrip:

titleStrip = (PagerTabStrip) pagerView.findViewById(R.id.pager_title_strip);

然后，你可以添加OnPageChangeListener到ViewPager，你可以在onPageSelected方法中做任何你想做的事情:

then, you can add OnPageChangeListener to ViewPager, you can do anything you want in onPageSelected method:

mPager.setOnPageChangeListener(new OnPageChangeListener() {

    @Override
    public void onPageSelected(int position) {
        switch (position) {
        case 0:
            titleStrip.setBackgroundColor(Color.BLUE);
            break;

        case 1:
            titleStrip.setBackgroundColor(Color.GRAY);
            break;
        }
    }

    @Override
    public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
    }

    @Override
    public void onPageScrollStateChanged(int state) {
    }
});

这篇关于使用位置更改 PagerTabStrip 的背景颜色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！