Android fragments 将Gridview添加到片段中'；它撞坏了

我正在遵循一个教程，并试图将网格视图构建到我的片段中，每次启动应用程序时，它都会崩溃。我打开LogCat，它什么也没给我。。。有人能帮我找出我能做些什么，让它正确显示，而不是崩溃的应用程序？谢谢你

下面我介绍了我的主要活动，GridView适配器和片段

main活动

import android.app.Activity;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.widget.DrawerLayout;
import android.support.v7.app.ActionBar;
import android.support.v7.app.ActionBarActivity;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;


   import android.view.ViewGroup;


public class MainActivity extends ActionBarActivity
        implements NavigationDrawerFragment.NavigationDrawerCallbacks {

    /**
     * Fragment managing the behaviors, interactions and presentation of the navigation drawer.
     */
    private NavigationDrawerFragment mNavigationDrawerFragment;

    /**
     * Used to store the last screen title. For use in {@link #restoreActionBar()}.
     */
    private Char

Sequence mTitle;

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

    mNavigationDrawerFragment = (NavigationDrawerFragment)
            getSupportFragmentManager().findFragmentById(R.id.navigation_drawer);

    // Set the first title
    mTitle = "Inventory";

    // Set up the drawer.
    mNavigationDrawerFragment.setUp(
            R.id.navigation_drawer,
            (DrawerLayout) findViewById(R.id.drawer_layout));

    // Remove shadow under actionbar
    getSupportActionBar().setElevation(0);
}

@Override
public void onNavigationDrawerItemSelected(int position) {

    Fragment objFragment = null;

    switch (position) {
        case 0:
            objFragment = new Inventory_Fragment();
            mTitle = getString(R.string.title_section1);
            break;
        case 1:
            objFragment = new Orders_Fragment();
            mTitle = getString(R.string.title_section2);
            break;
        case 2:
            objFragment = new Cart_Fragment();
            mTitle = getString(R.string.title_section3);
            break;
        case 3:
            objFragment = new Settings_Fragment();
            mTitle = getString(R.string.title_section4);
            break;
    }


    // update the main content by replacing fragments
    FragmentManager fragmentManager = getSupportFragmentManager();
    fragmentManager.beginTransaction()
            .replace(R.id.container, objFragment)
            .commit();
}

public void onSectionAttached(int number) {
    switch (number) {
        case 1:
            mTitle = getString(R.string.title_section1);
            break;
        case 2:
            mTitle = getString(R.string.title_section2);
            break;
        case 3:
            mTitle = getString(R.string.title_section3);
            break;
        case 4:
            mTitle = getString(R.string.title_section4);
            break;
    }
}

public void restoreActionBar() {
    ActionBar actionBar = getSupportActionBar();
    actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_STANDARD);
    actionBar.setDisplayShowTitleEnabled(true);
    actionBar.setTitle(mTitle);
}


@Override
public boolean onCreateOptionsMenu(Menu menu) {
    if (!mNavigationDrawerFragment.isDrawerOpen()) {
        // Only show items in the action bar relevant to this screen
        // if the drawer is not showing. Otherwise, let the drawer
        // decide what to show in the action bar.
        getMenuInflater().inflate(R.menu.main, menu);
        restoreActionBar();
        return true;
    }
    return super.onCreateOptionsMenu(menu);
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int id = item.getItemId();

    return super.onOptionsItemSelected(item);
}

/**
 * A placeholder fragment containing a simple view.
 */
public static class PlaceholderFragment extends Fragment {
    /**
     * The fragment argument representing the section number for this
     * fragment.
     */
    private static final String ARG_SECTION_NUMBER = "section_number";

    /**
     * Returns a new instance of this fragment for the given section
     * number.
     */
    public static PlaceholderFragment newInstance(int sectionNumber) {
        PlaceholderFragment fragment = new PlaceholderFragment();
        Bundle args = new Bundle();
        args.putInt(ARG_SECTION_NUMBER, sectionNumber);
        fragment.setArguments(args);
        return fragment;
    }

    public PlaceholderFragment() {
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        View rootView = inflater.inflate(R.layout.inventory_layout, container, false);
        return rootView;
    }

    @Override
    public void onAttach(Activity activity) {
        super.onAttach(activity);
        ((MainActivity) activity).onSectionAttached(
                getArguments().getInt(ARG_SECTION_NUMBER));
    }
}

// MARK: - Helpers
public void setActionBarTitle(String title) {
    getSupportActionBar().setTitle(title);
}

}

GridViewAdapter

import android.content.Context;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.GridView;
import android.widget.ImageView;

/**
 * Created by kenbarlow on 5/20/15.
 */
public class GridViewAdapter extends BaseAdapter {
    private Context context;

    public GridViewAdapter(Context context) {
        context = context;
    }

    private int[] icons = {
            // Temporary
        R.drawable.image1,
        R.drawable.image2,
        R.drawable.image3,
        R.drawable.image4,
        R.drawable.image5,
        R.drawable.image6,
        R.drawable.image7,
        R.drawable.image8,
        R.drawable.image9,
        R.drawable.image10,
        R.drawable.image11,
        R.drawable.image12,
        R.drawable.image13,
        R.drawable.image14,
        R.drawable.image15,
        R.drawable.image16,
        R.drawable.image17

};


@Override
public int getCount() {
    return icons.length;
}

@Override
public Object getItem(int position){
    return null;
}

@Override
public long getItemId(int position) {
    return 0;
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
    ImageView imageView;
    if (convertView == null) {
        imageView = new ImageView(context);
        imageView.setLayoutParams(new GridView.LayoutParams(100, 100));
        imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
        imageView.setPadding(10, 10, 10, 10);
    } else {
        imageView = (ImageView) convertView;
    }
    imageView.setImageResource(icons[position]);
    return imageView;
}
}

库存\u碎片---我觉得问题在这里，但我不确定。

import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.GridView;

/**
 * Created by kenbarlow on 5/19/15.
 */
public class Inventory_Fragment extends Fragment {

    View rootView;

    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        rootView = inflater.inflate(R.layout.inventory_layout, container, false);

    GridView gridview = (GridView) getActivity().findViewById(R.id.gridview);
    gridview.setAdapter(new GridViewAdapter(this));


    return rootView;
}

}

---

我还没有看过所有的代码。我回顾了GridViewAdapter和Inventory\u片段

删除

GridViewAdapter

中的

getItemId

方法。反正你也不用。

BaseAdapter

可能正在引用它，从该方法返回null可能会使适配器崩溃

代码建议，返回此方法的项目：

@Override
public Object getItem(int position){
    return icons[position];
}

---

我猜您正在尝试在活动的布局中查找gridview，这是错误的，因为gridview位于片段的布局中。 请更改您的片段代码：

public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    rootView = inflater.inflate(R.layout.inventory_layout, container, false);

    GridView gridview = (GridView) rootView.findViewById(R.id.gridview);
    if(gridview != null){
        gridview.setAdapter(new GridViewAdapter(getActivity()));
    }

    return rootView;
}

如果这不是问题的原因，请在崩溃发生时发布stacktrace（应该已经完成）

LogCat什么也没给我

如果实际上什么都没有，请尝试重置LogCat

正如我在这几行中看到的

rootView = inflater.inflate(R.layout.inventory_layout, container, false);

GridView gridview = (GridView) getActivity().findViewById(R.id.gridview);

您正在膨胀并生成rootView以查找内部布局。因此，不要使用第二行中的

getActivity（）

，而是使用rootView

---

请记住将gridView布局放在库存布局中，我不确定这是否是唯一的问题，但这一个看起来有点错误。 在您的Inventory_Fragment类中：

gridview.setAdapter(new GridViewAdapter(this));

您应该将其更改为：

gridview.setAdapter(new GridViewAdapter(getActivity()));

---

另外，请在此上传您的布局和/或logcat报告。像这样浏览代码是很困难的。

您能一步一步地浏览代码并查看代码在哪里崩溃吗？如果您在MainActivity中的super.onCreate（）上放置一个断点，它会到达该代码吗？我关心你的编译器设置。在此之前是否运行过其他应用程序？返回位置值@getItem方法，而不是null。