Question

Single.java

package baleli.movieapp.model;

/**
 * Created by wim on 4/14/16.
 */
public class Single {

    private int img;
    private String title;

    public Single() {
    }

    public int getImg() {
        return img;
    }

    public void setImg(int img) {
        this.img = img;
    }

    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }
}

MainActivity

package baleli.movieapp;

import android.support.v4.app.Fragment;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import baleli.movieapp.fragments.FragmentSingle;

public class MainActivity extends AppCompatActivity {

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

        Fragment fragment = getSupportFragmentManager().findFragmentById(android.R.id.content);
        if(fragment == null){
            fragment = FragmentSingle.newInstance();
            getSupportFragmentManager()
                    .beginTransaction()
                    .replace(android.R.id.content, fragment, "")
                    .commit();
        } else {
            getSupportFragmentManager()
                    .beginTransaction()
                    .attach(fragment)
                    .commit();
        }
    }
}

窗口小部件/ GridMarginDecoration

package baleli.movieapp.widgets;

import android.content.Context;
import android.graphics.Rect;
import android.support.v7.widget.RecyclerView;
import android.view.View;

/**
 * Created by wim on 4/14/16.
 */
public class GridMarginDecoration extends RecyclerView.ItemDecoration {

    private int left;
    private int right;
    private int top;
    private int bottom;

    public GridMarginDecoration(Context context, int left, int right, int top, int bottom) {

        this.left = left;
        this.right = right;
        this.top = top;
        this.bottom = bottom;
    }

    @Override
    public void getItemOffsets(
            Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
        outRect.set(left, top, right, bottom);
    }
}

片段/ FragmentSingle.java

package baleli.movieapp.fragments;

import android.content.Context;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v4.app.Fragment;
import android.support.v7.widget.GridLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Toast;

import java.util.ArrayList;
import java.util.List;

import baleli.movieapp.R;
import baleli.movieapp.adapter.SingleListAdapter;
import baleli.movieapp.model.Single;
import baleli.movieapp.widgets.GridMarginDecoration;

/**
 * Created by docotel on 4/14/16.
 */
public class FragmentSingle extends Fragment implements SingleListAdapter.OnGridItemSelectedListener{

    private RecyclerView lvSingle;
    private GridLayoutManager gridLayoutManager;
    private SingleListAdapter singleListAdapter;

    private Context context;

    public static FragmentSingle newInstance() {
        return new FragmentSingle();
    }

    @Override
    public void onAttach(Context context) {
        super.onAttach(context);
        this.context = context;
    }

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

        lvSingle = (RecyclerView) rootView.findViewById(R.id.lvSingle);

        return rootView;
    }

    @Override
    public void onActivityCreated(@Nullable Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);

        singleListAdapter = new SingleListAdapter(this);
        gridLayoutManager = new GridLayoutManager(context, 2);

        lvSingle.setLayoutManager(gridLayoutManager);
        lvSingle.addItemDecoration(new GridMarginDecoration(context, 2, 2, 2, 2));
        lvSingle.setAdapter(singleListAdapter);

        loadData();
    }

    private void loadData(){
        List<Single> singleList = new ArrayList<>();
        Single single;

        int img[] = {R.drawable.tariq, R.drawable.tariq,
                R.drawable.tariq, R.drawable.tariq,
                R.drawable.tariq, R.drawable.tariq,
                R.drawable.tariq, R.drawable.tariq};

        String title[] = {"AKB48 43rd Single - Kimi wa Melody", "AKB48 42nd Single - Kuchibiru ni Be My Baby",
                "AKB48 41st Single - Halloween Night", "AKB48 40th Single - Bokutachi wa Tatakawanai",
                "AKB48 39th Single - Green Flash", "AKB48 38th Single - Kibouteki Refrain",
                "AKB48 37th Single - Kokoro no Placard", "AKB48 36th Single - Labrador Retriever"};

        for (int i = 0; i < img.length; i++){
            single = new Single();

            single.setImg(img[i]);
            single.setTitle(title[i]);

            singleList.add(single);
        }

        singleListAdapter.addAll(singleList);
    }

    @Override
    public void onGridItemClick(View v, int position) {
        Toast.makeText(context, singleListAdapter.getItem(position).getTitle(), Toast.LENGTH_SHORT).show();
    }
}

适配器/ SingleListAdapter

package baleli.movieapp.adapter;

import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.TextView;

import java.util.ArrayList;
import java.util.List;

import baleli.movieapp.R;
import baleli.movieapp.model.Single;

/**
 * Created by wim on 4/14/16.
 */
public class SingleListAdapter extends RecyclerView.Adapter<SingleListAdapter.SingleViewHolder>{

    private List<Single> singleList;
    private OnGridItemSelectedListener onGridItemSelectedListener;

    public SingleListAdapter(OnGridItemSelectedListener onGridItemSelectedListener) {
        this.onGridItemSelectedListener = onGridItemSelectedListener;
        singleList = new ArrayList<>();
    }

    private void add(Single item) {
        singleList.add(item);
        notifyItemInserted(singleList.size() - 1);
    }

    public void addAll(List<Single> singleList) {
        for (Single single : singleList) {
            add(single);
        }
    }

    public void remove(Single item) {
        int position = singleList.indexOf(item);
        if (position > -1) {
            singleList.remove(position);
            notifyItemRemoved(position);
        }
    }

    public void clear() {
        while (getItemCount() > 0) {
            remove(getItem(0));
        }
    }

    public Single getItem(int position){
        return singleList.get(position);
    }

    @Override
    public SingleViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.list_item_single, parent, false);
        final SingleViewHolder singleViewHolder = new SingleViewHolder(view);

        singleViewHolder.itemView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                int adapterPos = singleViewHolder.getAdapterPosition();
                if (adapterPos != RecyclerView.NO_POSITION) {
                    if (onGridItemSelectedListener != null) {
                        onGridItemSelectedListener.onGridItemClick(singleViewHolder.itemView, adapterPos);
                    }
                }
            }
        });

        return singleViewHolder;
    }

    @Override
    public void onBindViewHolder(SingleViewHolder holder, int position) {
        final Single single = singleList.get(position);

        holder.img.setImageResource(single.getImg());
        holder.title.setText(single.getTitle());
    }

    @Override
    public int getItemCount() {
        return singleList.size();
    }

    @Override
    public void onAttachedToRecyclerView(RecyclerView recyclerView) {
        super.onAttachedToRecyclerView(recyclerView);
    }

    @Override
    public void onDetachedFromRecyclerView(RecyclerView recyclerView) {
        super.onDetachedFromRecyclerView(recyclerView);
    }

    public class SingleViewHolder extends RecyclerView.ViewHolder {

        ImageView img;
        TextView title;

        public SingleViewHolder(View itemView) {
            super(itemView);

            img = (ImageView) itemView.findViewById(R.id.img);
            title = (TextView) itemView.findViewById(R.id.title);
        }

    }

    public interface OnGridItemSelectedListener {
        void onGridItemClick(View v, int position);
    }

}

的AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="baleli.movieapp">
<uses-permission android:name="android.permission.INTERNET"/>
    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

Activity_main

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="match_parent"
    android:layout_height="match_parent">

    <FrameLayout
        android:id="@android:id/content"
        android:layout_width="match_parent"
        android:layout_height="match_parent">

    </FrameLayout>

</LinearLayout>

fragment_single.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <android.support.v7.widget.RecyclerView
        android:id="@+id/lvSingle"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:scrollbars="vertical"
        android:padding="1dp"/>


</LinearLayout>

list_item_single.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <RelativeLayout
        android:layout_width="200dp"
        android:layout_height="200dp">

        <ImageView
            android:id="@+id/img"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:scaleType="centerCrop" />

        <TextView
            android:id="@+id/title"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:textSize="14sp"
            android:background="#40000000"
            android:padding="8dp"
            android:textColor="#FFFFFF"
            android:layout_alignParentBottom="true"
            android:layout_alignParentLeft="true"
            android:layout_alignParentStart="true" />

    </RelativeLayout>

</RelativeLayout>

我创建了带有片段和recyclerview的gridlayout。项目完成gradle没有错误。但是当我在genymotion中运行我的应用程序时，我收到以下错误。不幸的是，应用已停止。我有Logcat的截图，我在这里发帖。

所以帮助我。怎么修。提前谢谢......

Answer 1

您必须首先检查您是否拥有资源ID的天气，然后尝试在图像视图中进行设置。

SupportSQLiteOpenHelper

Answer 2

Tariq Aziz。
尝试捕获异常，也许single.getImg（）为null或为空。

@Override
public void onBindViewHolder(SingleViewHolder holder, int position) {
    final Single single = singleList.get(position);

    try {  
        holder.img.setImageResource(single.getImg());
    } catch (Exception e) {
        // Not found
    }
    holder.title.setText(single.getTitle());
}

不幸的是，应用已停止，如何解决？

2 个答案: