如何使用getResources方法正确显示图像？

时间：2015-04-18 17:47:04

标签： java android android-listview

我基本上创建了一个购物车应用程序，我正在尝试使用项目的图像填充listView。因此，目前其他所有内容都显示得很好，如大小，商店，描述，价格等。所有这些信息都是从我现有的数据库中检索出来并放入listView。对于图像，我已将图像的名称放在我的数据库中名为ID的列中，并将实际图像放入我的drawable文件夹中。为了使图像显示各自的项目，我使用getResources方法，但由于某种原因，它不起作用，它不会显示图像。我已经发布了下面的代码，您将在我的ListItemAdapter.java中看到getResources方法。如果有人能够解决这个问题并修复它，那就太好了。

DatabaseHelper.java 

package ankitkaushal.app.healthysizing;

import android.content.Context;
import android.database.Cursor;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteException;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;

import junit.framework.Assert;

import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.ArrayList;

public class DatabaseHelper extends SQLiteOpenHelper {

    public static String DB_PATH = "/data/data/ankitkaushal.app.healthysizing/databases/";
    public static String DB_NAME = "healthysizing";
    public static final int DB_VERSION = 1;
    public static final String TB_USER = "Shirts";
    private SQLiteDatabase myDB;
    private Context context;

    public DatabaseHelper(Context context) {
        super(context, DB_NAME, null, DB_VERSION);
        this.context = context;
    }

    @Override
    public void onCreate(SQLiteDatabase db) {
        // TODO Auto-generated method stub

    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        // TODO Auto-generated method stub

    }

    @Override
    public synchronized void close(){
        if(myDB!=null){
            myDB.close();
        }
        super.close();
    }

    /*public List<String> getAllUsers() {
        List<String> listUsers = new ArrayList<String>();
        SQLiteDatabase db = this.getWritableDatabase();
        Cursor c;

        try {
            c = db.rawQuery("SELECT * FROM " + TB_USER , null);
            if(c == null) return null;

            String name;
            c.moveToFirst();
            do {
                name = c.getString(5);
                listUsers.add(name);
            } while (c.moveToNext());
            c.close();
        } catch (Exception e) {
            Log.e("tle99", e.getMessage());
        }


        db.close();

        return listUsers;
    } */

    /*public List<Item> getAllShirts() {

        List<Item> shirtList = new ArrayList<Item>();
        String query = "SELECT * FROM " + TB_USER; //query to get all the shirts
        SQLiteDatabase db = this.getWritableDatabase();
        Cursor cursor = db.rawQuery(query, null);

        if (cursor.moveToFirst()){
            do {
                Item item = new Item();
                item.setPrice(cursor.getString(2));
                item.setBrand(cursor.getString(1));
                item.setStore(cursor.getString(3));
                item.setDescription(cursor.getString(5));
                shirtList.add(item);
            } while (cursor.moveToNext());
        }

        return shirtList;

    }*/

    public ArrayList<Item> getAllSearchedShirts(String brand) {

        ArrayList<Item> shirtList = new ArrayList<Item>();
        String query = "SELECT * FROM " + TB_USER + " WHERE Brand LIKE '" + brand + "' ORDER BY Price ASC"; //query to get all the shirts for brand typed in
        SQLiteDatabase db = this.getWritableDatabase();
        Cursor cursor = db.rawQuery(query, null);

        if (cursor.moveToFirst()){
            do {
                Item item = new Item();
                item.setBrand(cursor.getString(0));
                item.setStore(cursor.getString(1));
                item.setPrice(cursor.getString(2));
                item.setDescription(cursor.getString(3));
                item.setSize(cursor.getString(4));
                item.setID(cursor.getString(6));
                shirtList.add(item);
            } while (cursor.moveToNext());
        }

        return shirtList;

    }

    public ArrayList<Item> getAllShirts() {

        ArrayList<Item> shirtList = new ArrayList<Item>();
        String query = "SELECT * FROM " + TB_USER + " ORDER BY Price ASC"; //query to get all the shirts
        SQLiteDatabase db = this.getWritableDatabase();
        Cursor cursor = db.rawQuery(query, null);

        if (cursor.moveToFirst()){
            do {
                Item item = new Item();
                item.setBrand(cursor.getString(0));
                item.setStore(cursor.getString(1));
                item.setPrice(cursor.getString(2));
                item.setDescription(cursor.getString(3));
                item.setSize(cursor.getString(4));
                item.setID(cursor.getString(6));
                shirtList.add(item);
            } while (cursor.moveToNext());
        }

        return shirtList;

    }

    /*public Cursor getShirtsData() {
        String SQLQuery = "SELECT * FROM" + TB_USER;
        return myDB.rawQuery(SQLQuery, null);
    } */


    /***
     * Open database
     * @throws android.database.SQLException
     */
    public void openDataBase() throws SQLException {
        String myPath = DB_PATH + DB_NAME;
        myDB = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READWRITE);
    }

    /**
     * Copy database from source code assets to device
     * @throws java.io.IOException
     */
    public void copyDataBase() throws IOException {
        try {
            InputStream myInput = context.getAssets().open(DB_NAME);
            String outputFileName = DB_PATH + DB_NAME;
            OutputStream myOutput = new FileOutputStream(outputFileName);

            byte[] buffer = new byte[1024];
            int length;

            while((length = myInput.read(buffer))>0){
                myOutput.write(buffer, 0, length);
            }

            myOutput.flush();
            myOutput.close();
            myInput.close();
        } catch (Exception e) {
            Log.e("tle99 - copyDatabase", e.getMessage());
        }

    }

    /***
     * Check if the database doesn't exist on device, create new one
     * @throws IOException
     */
    public void createDataBase() throws IOException {
        boolean dbExist = checkDataBase();

        if (dbExist) {

        } else {
            this.getReadableDatabase();
            try {
                copyDataBase();
            } catch (IOException e) {
                Log.e("tle99 - create", e.getMessage());
            }
        }
    }

    // ---------------------------------------------
    // PRIVATE METHODS
    // ---------------------------------------------

    /***
     * Check if the database is exist on device or not
     * @return
     */
    private boolean checkDataBase() {
        SQLiteDatabase tempDB = null;
        try {
            String myPath = DB_PATH + DB_NAME;
            tempDB = SQLiteDatabase.openDatabase(myPath, null,
                    SQLiteDatabase.OPEN_READWRITE);
        } catch (SQLiteException e) {
            Log.e("tle99 - check", e.getMessage());
        }
        if (tempDB != null)
            tempDB.close();
        return tempDB != null ? true : false;
    }

}

ListItemAdapter.java 

package ankitkaushal.app.healthysizing;

import java.util.ArrayList;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ImageView;
import android.widget.TextView;

public final class ListItemAdapter extends ArrayAdapter<Item> implements View.OnClickListener{

    public ListItemAdapter(Context context, ArrayList<Item> shirtItems) {
        super(context, 0, shirtItems);
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {

        // Get the data item for this position
        Item item = getItem(position);

        // Check if an existing view is being reused, otherwise inflate the view
        if (convertView == null) {
            convertView = LayoutInflater.from(getContext()).inflate(R.layout.item_layout_shirts, parent, false);
        }

        // Lookup view for data population
        TextView brand = (TextView) convertView.findViewById(R.id.txt_shirt_brand);
        TextView price = (TextView) convertView.findViewById(R.id.txt_shirt_price);
        TextView store = (TextView) convertView.findViewById(R.id.txt_shirt_store);
        TextView size = (TextView) convertView.findViewById(R.id.txt_shirt_size);
        TextView description = (TextView) convertView.findViewById(R.id.txt_shirt_description);
        ImageView shirtsImage = (ImageView) convertView.findViewById(R.id.image_view_shirts);

        // Populate the data into the template view using the data object
        brand.setText("Brand:" + "  " + item.getBrand());
        price.setText("Price:" + "  $" + item.getPrice());
        store.setText("Store:" + "  " + item.getStore());
        size.setText("Size:" + "  " + item.getSize());
        description.setText("Description:" + "  " + item.getDescription());

        Context context = parent.getContext();
        int shirtsID = context.getResources().getIdentifier(item.getID(), "drawable", ListItemAdapter.class.getPackage().getName());
        //int shirtsID = context.getResources().getIdentifier("packagename:drawable/" + item.getID(), null, null);
        shirtsImage.setImageResource(shirtsID);

        // Return the completed view to render on screen
        return convertView;

    }

    @Override
    public void onClick(View v) {
        // TODO Auto-generated method stub

    }

}

shirtsActivity.java 

package ankitkaushal.app.healthysizing;

import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.util.Log;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.SearchView;
import java.io.IOException;
import java.util.ArrayList;
import android.content.res.Resources;

public class shirtsActivity extends ActionBarActivity {

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_shirts);

        final SearchView shirtViewShirts = (SearchView) findViewById(R.id.searchView3);
        final DatabaseHelper dbhelper;
        final ListView listView;
        final ListAdapter shirtsAdapter;

        dbhelper = new DatabaseHelper(getApplicationContext());
        try {
            dbhelper.createDataBase();
        } catch (IOException e) {
            e.printStackTrace();
        }

        listView = (ListView) findViewById(R.id.listViewShirts);
        //List<Item> shirtsList = dbhelper.getAllShirts();
        ArrayList<Item> shirtsList = dbhelper.getAllShirts();

        if (shirtsList != null) {
            //shirtsAdapter = new ArrayAdapter<Item>(getApplicationContext(), android.R.layout.simple_list_item_1, android.R.id.text1, shirtsList);
            shirtsAdapter = new ListItemAdapter(getApplicationContext(), shirtsList);
            listView.setAdapter(shirtsAdapter);
        }

        shirtViewShirts.setOnQueryTextListener(new SearchView.OnQueryTextListener() {

            @Override
            public boolean onQueryTextSubmit(String query) {

                //query = query.toLowerCase();
                //query = Character.toString(query.charAt(0)).toUpperCase()+query.substring(1);

                ListAdapter searchedShirtsAdapter;
                Log.e("Brand: ", query);
                ArrayList<Item> searchedShirtsList = dbhelper.getAllSearchedShirts(query);

                if (searchedShirtsList != null) {
                    searchedShirtsAdapter = new ListItemAdapter(getApplicationContext(), searchedShirtsList);
                    listView.setAdapter(searchedShirtsAdapter);
                }

                listView.setEmptyView(findViewById(R.id.empty_shirts_message));

                return false;
            }

            @Override
            public boolean onQueryTextChange(String newText) {
                return false;
            }

        });

    }

}

Item.java 

package ankitkaushal.app.healthysizing;

public class Item {

    private String brand;
    private String size;
    private String price;
    private String store;
    private String description;
    private String ID;
    private String gender;

    public Item() {

    }

    public void setBrand(String brand) {
        this.brand = brand;
    }

    public void setSize(String size) {
        this.size = size;
    }

    public void setID(String ID) {
        this.ID = ID;
    }

    public void setGender(String gender) {
        this.gender = gender;
    }

    public void setPrice(String price) {
        this.price = price;
    }

    public void setStore(String store) {
        this.store = store;
    }

    public void setDescription(String description) {this.description = description;}

    public String getStore() {
        return store;
    }

    public String getPrice() {
        return price;
    }

    public String getGender() {return gender; }

    public String getSize() {
        return size;
    }

    public String getBrand() {
        return brand;
    }

    public String getID() {
        return ID;
    }

    public String getDescription() {return description; }

    @Override
    public String toString() {
        return (this.brand + "  " + this.store + "  " + this.price + "  " + this.description);
    }

}

item_layout_shirts.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">

    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textAppearance="?android:attr/textAppearanceMedium"
            android:text="Medium Text"
            android:id="@+id/txt_shirt_price"
            android:layout_alignParentTop="true"
            android:layout_alignRight="@+id/button"
            android:layout_alignEnd="@+id/button"
            android:layout_marginBottom="5dp"
            android:layout_marginLeft="-5dp"
            android:layout_marginTop="15dp" />

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textAppearance="?android:attr/textAppearanceMedium"
            android:text="Medium Text"
            android:id="@+id/txt_shirt_brand"
            android:layout_below="@+id/txt_shirt_price"
            android:layout_alignLeft="@+id/txt_shirt_price"
            android:layout_alignStart="@+id/txt_shirt_price"
            android:layout_marginBottom="5dp" />

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textAppearance="?android:attr/textAppearanceMedium"
            android:text="Medium Text"
            android:id="@+id/txt_shirt_store"
            android:layout_below="@+id/txt_shirt_brand"
            android:layout_alignLeft="@+id/txt_shirt_brand"
            android:layout_alignStart="@+id/txt_shirt_brand"
            android:layout_marginBottom="5dp" />

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textAppearance="?android:attr/textAppearanceMedium"
            android:text="Medium Text"
            android:id="@+id/txt_shirt_size"
            android:layout_below="@+id/txt_shirt_store"
            android:layout_alignLeft="@+id/txt_shirt_store"
            android:layout_alignStart="@+id/txt_shirt_store" />

        <Button
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Add item to Cart"
            android:id="@+id/button"
            android:layout_below="@+id/txt_shirt_description"
            android:layout_centerHorizontal="true"
            android:layout_marginTop="15dp" />

        <ImageView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/image_view_shirts"
            android:layout_alignParentLeft="true"
            android:layout_alignParentStart="true"
            android:layout_toStartOf="@+id/button"
            android:layout_alignBottom="@+id/txt_shirt_size"
            android:layout_alignParentTop="true"
            android:src="@drawable/shirts"
            android:layout_marginLeft="10dp"
            android:layout_toLeftOf="@+id/button"
            android:layout_marginBottom="-20dp"
            android:layout_marginRight="-25dp"
            android:layout_marginTop="10dp" />

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textAppearance="?android:attr/textAppearanceMedium"
            android:text="Medium Text"
            android:id="@+id/txt_shirt_description"
            android:layout_below="@+id/image_view_shirts"
            android:layout_alignParentLeft="true"
            android:layout_alignParentStart="true"
            android:layout_marginTop="20dp" />

    </RelativeLayout>

</LinearLayout>

activity_shirts.xml 

<?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"
    android:background="#29A9D2"
    android:weightSum="1"
    android:id="@+id/shirt">

    <SearchView
        android:layout_width="358dp"
        android:layout_height="wrap_content"
        android:id="@+id/searchView3"
        android:background="#ffffffff"
        android:queryHint="Search for specific brand" />

    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <ListView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/listViewShirts"
            android:layout_alignParentTop="true"
            android:layout_alignParentLeft="true"
            android:layout_alignParentStart="true"/>

        <TextView
            android:id="@+id/empty_shirts_message"
            android:text="No Results Found"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center"
            android:textColor="#FFFFFF"
            android:gravity="center|top"
            android:textSize="25dp"
            android:layout_alignParentRight="true"
            android:layout_alignParentEnd="true"
            android:layout_alignParentTop="true"
            android:layout_alignParentLeft="true"
            android:layout_alignParentStart="true"
            android:visibility="invisible"
            android:layout_marginTop="10dp"/>

    </RelativeLayout>

</LinearLayout>

2 个答案:

答案 0 :(得分：1)

您可以更简单的方式访问res / drawable中的Drawables。

context.getResources().getDrawable(R.drawable.<drawablename>

答案 1 :(得分：0)

<强>分析：

实际上要访问apk中定义的可绘制资源，当您动态访问它们时，必须使用包名称引用它们

引用您的代码

String itemName = item.getID(); 
int name = Integer.parseInt(itemName); 
Drawable drawable = context.getResources().getDrawable(name); 
shirtsImage.setImageDrawable(drawable);

我的项目中有关如何完成此操作的示例（根据您的需要修改以下代码）

    Drawable res1 = null;
    String uri1 = null;
    try {
        //First image
        uri1 = "@drawable/"+imageSplitted[0];
        int imageResource1 = context.getResources().getIdentifier(uri1, null, context.getApplicationContext().getPackageName());
        res1 = context.getResources().getDrawable(imageResource1);
    } catch (Exception e) {
        // TODO Auto-generated catch block
        //int imageResource1 = context.getResources().getIdentifier(uri1, null, context.getApplicationContext().getPackageName());
        res1 = context.getResources().getDrawable(R.drawable.ic_launcher);// Default image
    }

使用上面的代码执行类似这样的操作

    Drawable res1 = null;
    String uri1 = null;
    try {
        //First image
        String itemName = item.getID(); 
        uri1 = "@drawable/"+itemName;
        int imageResource1 = context.getResources().getIdentifier(uri1, null, context.getApplicationContext().getPackageName());
        res1 = context.getResources().getDrawable(imageResource1);
    } catch (Exception e) {
        // TODO Auto-generated catch block
        //int imageResource1 = context.getResources().getIdentifier(uri1, null, context.getApplicationContext().getPackageName());
        res1 = context.getResources().getDrawable(R.drawable.ic_launcher);// Default image
    }

希望这会有所帮助！

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