Error importing jar package V4 in Android

Could not find class ' Android.support.v4.view.ViewPager ', referenced from method Com.maitao.spacepar

Sometimes, you will feel a lot of mistakes encountered, but once again met, still will be tempted to open the Web page ..... I wish I could write down all the mistakes I've made at once. Or...

This is the same as this V4jar package imported from Android this time ... So... Write it down. Write down the solution ... I don't know if there are any other quick ways. Now, you are using this method to solve ... Hope someone else offers better ear methods ... Don't make mistakes next time.

Error importing jar package V4 in Android