android - 将图像从 JSON 解析为 Android 中的 ListView

Question

我无法将图像从我的 JSON 文件加载到 Android 中的 ListView

我知道我必须使用 BitmapFactory.decodeStream 但除此之外我不确定如何实现它

这是我的适配器和 Activity

public class JSON {

static InputStream is = null;

static String jsonString = "";

static JSONObject jObj = null;

public JSON() {

}

public JSONObject getJSONFromUrl(String urlString) {

    try {
        URL url = new URL(urlString);
        HttpURLConnection con = (HttpURLConnection) url.openConnection();
        is = con.getInputStream();
    } catch (Exception e) {
        Log.v("NETWORK ERROR #1", e.getMessage());
    }

    StringBuilder sb = new StringBuilder();
    BufferedReader reader = null;
    try {
        reader = new BufferedReader(new InputStreamReader(is));

        String line = "";
        while ((line = reader.readLine()) != null) {
            sb.append(line);
        }
    } catch (IOException e) {
        Log.v("NETWORK ERROR #2 ", e.getMessage());
    } finally {
        if (reader != null) {
            try {
                reader.close();
            } catch (IOException e) {
                Log.v("NETWORK ERROR #3", e.getMessage());
            }

            jsonString = sb.toString();
        }
    }

    try {
        jObj = new JSONObject(jsonString);
    } catch (JSONException e) {
        Log.e("JSON Parser", "Error parsing data " + e.toString());
    }

    return jObj;
    }
}

---

public class Main2Activity extends ListActivity {

//JSON URL
private static String url = "http://pastebin.com/raw.php?i=8eTR5TXv";

private static final String ALBUMS = "album";

private static final String C_ALBUMS = "c_album";
private static final String C_ARTISTS = "c_artist";
private static final String C_DATES = "c_date";
private static final String C_RATINGS = "c_rating";
private static final String C_PICS = "c_pic";

JSONArray albumType = null;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main2);

    //Turn off StrictMode
    StrictMode.ThreadPolicy policy = new StrictMode.
            ThreadPolicy.Builder().permitAll().build();
    StrictMode.setThreadPolicy(policy);

    ArrayList<HashMap<String, String>> contactList = new ArrayList<HashMap<String, String>>();

    JSON jParser = new JSON();

    JSONObject json = jParser.getJSONFromUrl(url);

    try {
        albumType = json.getJSONArray(ALBUMS);

        for(int i = 0; i < albumType.length(); i++){
            JSONObject a = albumType.getJSONObject(i);

            String cAlbum = a.getString(C_ALBUMS);
            String cArtist = a.getString(C_ARTISTS);
            String cDate = a.getString(C_DATES);
            String cRating = a.getString(C_RATINGS);
            String cPic = a.getString(C_PICS);

            HashMap<String, String> map = new HashMap<String, String>();

            map.put(C_ALBUMS, cAlbum);
            map.put(C_ARTISTS, cArtist);
            map.put(C_DATES, cDate);
            map.put(C_RATINGS, cRating);
            map.put(C_PICS, cPic);

            contactList.add(map);
        }

    } catch (JSONException e) {
        e.printStackTrace();
    }

    ListAdapter adapter = new SimpleAdapter(
            this,
            contactList,
            R.layout.row2,
            new String[] { C_ALBUMS, C_ARTISTS, C_DATES, C_RATINGS, C_PICS },
            new int[] {R.id.tv_albumName, R.id.tv_Artist, R.id.tv_Date, R.id.tv_Rating, R.id.tv_pic}
    );

    setListAdapter(adapter);
}

和 XML

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="@string/ALBUM_NAME"
    android:id="@+id/tv_albumName"
    android:textSize="20sp"
    android:layout_alignParentTop="true"
    android:layout_alignParentLeft="true"
    android:layout_alignParentStart="true" />

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="@string/ARTIST"
    android:id="@+id/tv_Artist"
    android:textSize="12sp"
    android:layout_below="@+id/tv_albumName"
    android:layout_alignLeft="@+id/tv_albumName"
    android:layout_alignStart="@+id/tv_albumName" />

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="@string/DATE"
    android:id="@+id/tv_Date"
    android:textSize="12sp"
    android:layout_below="@+id/tv_Artist"
    android:layout_alignLeft="@+id/tv_Artist"
    android:layout_alignStart="@+id/tv_Artist" />

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="@string/RATING"
    android:id="@+id/tv_Rating"
    android:textSize="12sp"
    android:layout_below="@+id/tv_Date"
    android:layout_alignLeft="@+id/tv_Date"
    android:layout_alignStart="@+id/tv_Date" />

<ImageView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/tv_pic"
    android:layout_alignBottom="@+id/tv_Date"
    android:layout_alignParentRight="true"
    android:layout_alignParentEnd="true"
    android:padding="1sp"/>

非常感谢任何帮助，谢谢

Answer 1

你只需要使用像Picasso 这样的Image Loader 库, Glide .

希望此链接有助于使用 Introduction to Glide, Image Loader Library for Android, recommended by Google

毕加索:

Picasso.with(context)
    .load("http://inthecheesefactory.com/uploads/source/glidepicasso/cover.jpg")
    .into(ivImg);

滑行:

Glide.with(context)
    .load("http://inthecheesefactory.com/uploads/source/glidepicasso/cover.jpg")
    .into(ivImg);

或者你可以试试Universal Image Loader Library in Android

//your image url
String url = "Your Image URL";

ImageLoader imageLoader = ImageLoader.getInstance();
DisplayImageOptions options = new DisplayImageOptions.Builder().cacheInMemory(true)
                .cacheOnDisc(true).resetViewBeforeLoading(true)
                .showImageForEmptyUri(fallback)
                .showImageOnFail(fallback)
                .showImageOnLoading(fallback).build();

//initialize image view
ImageView imageView = (ImageView) findViewById(R.id.imageView1)     

//download and display image from url
imageLoader.displayImage(url, imageView, options);