Android Studio 无法解析 fragmentActivity 和 ViewPager 导入 [英] Android Studio Can't resolve fragmentActivity and ViewPager imports

问题描述

我遵循开发可滑动标签的教程.当我导入时:

I follow the tutorial of developing swipe-able tabs. When I import:

import android.support.v4.app.FragmentActivity;
import android.support.v4.view.ViewPager;

Android Studio 显示我无法解析符号ViewPager"和FragmentActivity".如何解决这个问题?谢谢.

Android Studio shows me cannot resolve the symbol "ViewPager" and "FragmentActivity". How to solve this? thanks.

以下是我项目的完整代码.

Below is the entire code of my project.

import android.app.ActionBar;
import android.app.ActionBar.Tab;
import android.app.FragmentTransaction;
import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
import android.support.v4.view.ViewPager;

public class MainActivity extends FragmentActivity implements
    ActionBar.TabListener {

private ViewPager viewPager;
private TabsPagerAdapter mAdapter;
private ActionBar actionBar;
// Tab titles
private String[] tabs = { "Top Rated", "Games", "Movies" };

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    // Initilization
    viewPager = (ViewPager) findViewById(R.id.pager);
    actionBar = getActionBar();
    mAdapter = new TabsPagerAdapter(getSupportFragmentManager());

    viewPager.setAdapter(mAdapter);
    actionBar.setHomeButtonEnabled(false);
    actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);

    // Adding Tabs
    for (String tab_name : tabs) {
        actionBar.addTab(actionBar.newTab().setText(tab_name)
                .setTabListener(this));
    }

    /**
     * on swiping the viewpager make respective tab selected
     * */
    viewPager.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {

        @Override
        public void onPageSelected(int position) {
            // on changing the page
            // make respected tab selected
            actionBar.setSelectedNavigationItem(position);
        }

        @Override
        public void onPageScrolled(int arg0, float arg1, int arg2) {
        }

        @Override
        public void onPageScrollStateChanged(int arg0) {
        }
    });
}

@Override
public void onTabReselected(Tab tab, FragmentTransaction ft) {
}

@Override
public void onTabSelected(Tab tab, FragmentTransaction ft) {
    // on tab selected
    // show respected fragment view
    viewPager.setCurrentItem(tab.getPosition());
}

@Override
public void onTabUnselected(Tab tab, FragmentTransaction ft) {
}

}

推荐答案

1. 确保您已使用 SDK 管理器下载了 Android 支持库.
2. 打开应用程序的 build.gradle 文件.

3. 将支持库添加到依赖项部分.例如，要添加 v4 支持库，请添加以下几行:

1. Make sure you have downloaded the Android Support Repository using the SDK Manager.
2. Open the build.gradle file for your application.

3. Add the support library to the dependencies section. For example, to add the v4 support library, add the following lines:

依赖项{...编译com.android.support:support-v4:18.0.+"}

dependencies { ... compile "com.android.support:support-v4:18.0.+" }

这篇关于Android Studio 无法解析 fragmentActivity 和 ViewPager 导入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IT屋！