如何從網站下載圖片並設置在圖片查看器

Question

for (int i = 0; i < productsofitems.length(); i++) 
        { 
         count=productsofitems.length(); 
         System.out.println("count is"+productsofitems.length()); 
         JSONObject c = productsofitems.getJSONObject(i); 

         // Storing each json item in variable 
         //String id = c.getString(TAG_CATEGORYID); 
         String procid = c.getString(TAG_PRODUCTID); 
         System.out.println(procid); 
         String id = c.getString(TAG_CATEGORYID); 
         System.out.println(id); 
         String productname = c.getString(TAG_PRODUCTNAME); 
         System.out.println(productname); 
         //String title = c.getString(TAG_TITLE); 
         //System.out.println(title); 
         //String smalldesc = c.getString(TAG_SMALLDESCRIPTION); 
         //System.out.println(smalldesc); 
         //String originalprice = c.getString(TAG_ORIGINALPRICE); 
         //System.out.println(originalprice); 
         String salesprice = c.getString(TAG_SALEPRICE); 
         System.out.println(salesprice); 
         String smallimage = c.getString(TAG_SMALLIMAGE); 
         System.out.println(smallimage); 

         String stocks = c.getString(TAG_STOCK); 
         System.out.println(stocks); 


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

         // adding each child node to HashMap key => value 
         map.put(TAG_PRODUCTID, procid); 
         map.put(TAG_CATEGORYID, id); 
         map.put(TAG_PRODUCTNAME, productname); 
         //map.put(TAG_TITLE, title); 
         //map.put(TAG_SMALLDESCRIPTION, smalldesc); 
         //map.put(TAG_ORIGINALPRICE, originalprice); 
         map.put(TAG_SALEPRICE, salesprice); 
         map.put(TAG_SMALLIMAGE, smallimage); 
         map.put(TAG_STOCK, stocks); 

         // adding HashList to ArrayList 
         productListofitems.add(map); 

         System.out.println("inside"+count); 

        } 

       } 
       else { 
        Log.d("ProductListofitems: ", "null"); 
        // no products found 
        // Launch Add New product Activity 
        //Intent i = new Intent(getApplicationContext(), 
          //NewProductActivity.class); 
        // Closing all previous activities 
        //i.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP); 
        // startActivity(i); 
       } 
      } 
      catch (JSONException e) { 
       e.printStackTrace(); 
      } 

      return null; 
     } 

     /** 
     * After completing background task Dismiss the progress dialog 
     * **/ 
     protected void onPostExecute(String file_url) { 
      // dismiss the dialog after getting all category 
      pDialog.dismiss(); 
      // updating UI from Background Thread 
      runOnUiThread(new Runnable() { 
       public void run() { 
        /** 
        * Updating parsed JSON data into ListView 
        * */ 
        int[] images = { 
          R.drawable.a, R.drawable.banner2, 
          R.drawable.banner4, R.drawable.banner1 

        }; 
        ListAdapter adapter = new SimpleAdapter(
          ProductListofitems.this, productListofitems, 
          R.layout.productlistofitems, new String[] { 
            TAG_PRODUCTID,TAG_CATEGORYID,TAG_PRODUCTNAME,TAG_SALEPRICE,TAG_STOCK}, 
          new int[] {R.id.product_id,R.id.catgory_id,R.id.title,R.id.saleprice,R.id.stock}); 
        // updating listview 
        setListAdapter(adapter); 
        System.out.println("post execute"); 
        textview.setText(+count+" results for "+"'"+cat_title+"'"); 
       } 
      }); 

     } 

如何從URL下載圖片。我得到的URL作爲響應，以及如何下載和設置在listview的imageview。如何從URL下載圖像並在imageview中設置？我已經附上了這個代碼。

Answer 1

試試這個：

private class LoadImage extends AsyncTask<String, String, Bitmap> { 

    @Override 
    protected void onPreExecute() { 
     super.onPreExecute(); 
    } 
    protected Bitmap doInBackground(String... args) { 
     //1 url 
     if(args.length == 1){ 
      Log.i("doInBack 1","length = 1 "); 
      try { 
       Bitmap bitmap = BitmapFactory.decodeStream((InputStream)new URL(args[0]).getContent()); 

      } catch (Exception e) { 
       e.printStackTrace(); 
      } 
     } 
     return bitmap; 
    } 
    protected void onPostExecute(Bitmap image) { 
     if(image != null){ 
      yourImageView.setBitmap(image); 

     } 
     } 
    } 

如何調用這個類？

new LoadImage().execute("https://www.yourUrl.com/image.jpg"); 

Answer 2

您可以使用this庫下載圖片。

要使用你必須把JAR放在你的Android項目的libs子文件夾中。

那麼只有你必須使用它

MainActivity.java

public class MainActivity extends Activity { 
    ImageLoader imageLoader; 
    ImageView image; 
    String imageUrl = "http://developer.android.com/design/media/design_elements_landing.png"; 

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

     // Create global configuration and initialize ImageLoader with this config 
     imageLoader = ImageLoader.getInstance(); 
     imageLoader.init(ImageLoaderConfiguration.createDefault(MainActivity.this)); 

     image = (ImageView) findViewById(R.id.image); 
     ImageLoader imageLoader = ImageLoader.getInstance(); 
     imageLoader.displayImage(imageUrl, image); 

    } 
} 

activity_main.xml中

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" 
    xmlns:tools="http://schemas.android.com/tools" 
    android:layout_width="match_parent" 
    android:layout_height="match_parent" 
    tools:context="${relativePackage}.${activityClass}" > 

    <ImageView 
     android:id="@+id/image" 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     android:text="@string/hello_world" /> 

</RelativeLayout> 

，最終包括在manifest.xml本線

<uses-sdk 
     android:minSdkVersion="8" 
     android:targetSdkVersion="21" /> 

    <!-- Include following permission if you load images from Internet --> 
    <uses-permission android:name="android.permission.INTERNET" /> 

    <application 
     android:allowBackup="true" 
     android:icon="@drawable/ic_launcher" 
     android:label="@string/app_name" 
     android:theme="@style/AppTheme" > 
     <activity 
      android:name=".MainActivity" 
      android:label="@string/app_name" > 
      <intent-filter> 
       <action android:name="android.intent.action.MAIN" /> 

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

Answer 3

public class ImageViewFromURLActivity extends Activity { 

    public static final String URL = 
     "https://encrypted-tbn3.gstatic.com/images?q=tbn:ANd9GcQm1U-h4oGaUpGTb9K7REF0ogGYprXYA2z7g8LGjS-7HUFooIwSV2qzHH-W"; 
    ImageView imageView; 

    /** Called when the activity is first created. */ 
    @Override 
    public void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.main); 
     imageView = (ImageView) findViewById(R.id.imageView); 

     // Create an object for subclass of AsyncTask 
     GetXMLTask task = new GetXMLTask(); 
     // Execute the task 
     task.execute(new String[] { URL }); 
    } 

    private class GetXMLTask extends AsyncTask<String, Void, Bitmap> { 
     @Override 
     protected Bitmap doInBackground(String... urls) { 
      Bitmap map = null; 
      for (String url : urls) { 
       map = downloadImage(url); 
      } 
      return map; 
     } 

     // Sets the Bitmap returned by doInBackground 
     @Override 
     protected void onPostExecute(Bitmap result) { 
      imageView.setImageBitmap(result); 
     } 

     // Creates Bitmap from InputStream and returns it 
     private Bitmap downloadImage(String url) { 
      Bitmap bitmap = null; 
      InputStream stream = null; 
      BitmapFactory.Options bmOptions = new BitmapFactory.Options(); 
      bmOptions.inSampleSize = 1; 

      try { 
       stream = getHttpConnection(url); 
       bitmap = BitmapFactory. 
         decodeStream(stream, null, bmOptions); 
       stream.close(); 
      } catch (IOException e1) { 
       e1.printStackTrace(); 
      } 
      return bitmap; 
     } 

     // Makes HttpURLConnection and returns InputStream 
     private InputStream getHttpConnection(String urlString) throws IOException { 
      InputStream stream = null; 
      URL url = new URL(urlString); 
      URLConnection connection = url.openConnection(); 

      try { 
       HttpURLConnection httpConnection = (HttpURLConnection) connection; 
       httpConnection.setRequestMethod("GET"); 
       httpConnection.connect(); 

       if (httpConnection.getResponseCode() == HttpURLConnection.HTTP_OK) { 
        stream = httpConnection.getInputStream(); 
       } 
      } catch (Exception ex) { 
       ex.printStackTrace(); 
      } 
      return stream; 
     } 
    } 
} 

Answer 4

// show The Image 

new DownloadImageTask((ImageView) findViewById(R.id.imageView1)) 
     .execute("http://java.sogeti.nl/JavaBlog/wp-content/uploads/2009/04/android_icon_256.png"); 
} 

public void onClick(View v) { 
startActivity(new Intent(this, IndexActivity.class)); 
finish(); 

} 

private class DownloadImageTask extends AsyncTask<String, Void, Bitmap> { 
ImageView bmImage; 

public DownloadImageTask(ImageView bmImage) { 
    this.bmImage = bmImage; 
} 

protected Bitmap doInBackground(String... urls) { 
    String urldisplay = urls[0]; 
    Bitmap mIcon11 = null; 
    try { 
     InputStream in = new java.net.URL(urldisplay).openStream(); 
     mIcon11 = BitmapFactory.decodeStream(in); 
    } catch (Exception e) { 
     Log.e("Error", e.getMessage()); 
     e.printStackTrace(); 
    } 
    return mIcon11; 
} 

protected void onPostExecute(Bitmap result) { 
    bmImage.setImageBitmap(result); 
    } 
    } 

Answer 5

添加畢加索罐子然後再調用這個 Picasso.with（this.getContext（）） .load（IMAGEURL） .into（ImageView的）;