Question

我正在使用视图寻呼机和片段制作应用。但它在发布时崩溃了所以请你帮我找到我的代码中的错误。我提供我的代码和Logcat。我正在从这个网站学习教程：https://www.androidhive.info/2013/10/android-tab-layout-with-swipeable-views-1/

我的Logcat：

package com.example.android.resume;

 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;

 import tabsswiper.TabsPagerAdapter;

 public class MainActivity extends FragmentActivity implements 
 ActionBar.TabListener {

private ViewPager viewPager;
private TabsPagerAdapter mAdapter;
private ActionBar actionBar;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    String[] tabs = {"About Me", "Sample Photos", "Book Me"};

    // Initilization
    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.addOnPageChangeListener(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) {
   }
}

Answer 1

使用AppCompactActivity代替FragmentActivity，并使用Toolbar 如

 toolbar = (Toolbar) findViewById(R.id.toolbar);
 setSupportActionBar(toolbar);
 getSupportActionBar().setDisplayHomeAsUpEnabled(true);

Answer 2

您可以使用getSupportActionBar()代替getActionBar()方法。

Answer 3

您应该使用getSupportActionBar()代替getActionBar()。

首先删除您的

导入

import android.app.ActionBar;

然后检查是否依赖于

声明了对v7的支持

compile 'com.android.support:appcompat-v7:+'

祝你好运。

Answer 4

尝试

getContext().getActionBar()

或

getContext().getSupportActionBar()

Answer 5

试试这个

package com.demotest;
import android.os.Bundle;
import android.support.v4.app.FragmentTransaction;
import android.support.v4.view.ViewPager;
import android.support.v7.app.ActionBar;
import android.support.v7.app.AppCompatActivity;

public class MainActivity  extends AppCompatActivity 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 = getSupportActionBar();
    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(MainActivity.this));
    }

    viewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
        @Override
        public void onPageScrolled(int position, float positionOffset, int 
    positionOffsetPixels) {
            actionBar.setSelectedNavigationItem(position);

        }

        @Override
        public void onPageSelected(int position) {

        }

        @Override
        public void onPageScrollStateChanged(int state) {

        }
    });
}




@Override
public void onTabSelected(ActionBar.Tab tab, FragmentTransaction ft) {
    viewPager.setCurrentItem(tab.getPosition());
}

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

}

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

}


}

我的应用程序在使用getActionBar（）启动时崩溃

5 个答案: