如何將圖像從Hashmap url添加到列表視圖項目中？

Question

在followimg類中，我使用散列表導入了一個拇指圖像，該圖像保存爲一個字符串。但是，我希望將此圖像通過一個意圖傳遞給一個列表視圖，即一個詳細視圖。如何在詳細的活動中將s_thumb字符串添加到 imageview？ 這裏是主要的活動，設置了底部的意圖：

import java.io.ByteArrayOutputStream; 
import java.util.ArrayList; 
import java.util.HashMap; 

import org.w3c.dom.Document; 
import org.w3c.dom.Element; 
import org.w3c.dom.NodeList; 


import android.app.Activity; 
import android.content.Intent; 
import android.graphics.Bitmap; 
import android.graphics.BitmapFactory; 
import android.os.Bundle; 
import android.view.View; 
import android.widget.AdapterView; 
import android.widget.ImageView; 
import android.widget.AdapterView.OnItemClickListener; 
import android.widget.ListView; 

public class CustomizedListView extends Activity { 
    // All static variables 
    static final String URL = "http://padihamcars.com/music.xml"; 
    // XML node keys 
    static final String KEY_SONG = "song"; // parent node 
    static final String KEY_ID = "id"; 
    static final String KEY_TITLE = "title"; 
    static final String KEY_ARTIST = "artist"; 
    static final String KEY_DURATION = "duration"; 
    static final String KEY_THUMB_URL = "thumb_url"; 

    ListView list; 
    LazyAdapter adapter; 

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


     final ArrayList<HashMap<String, String>> songsList = new ArrayList<HashMap<String, String>>(); 

     XMLParser parser = new XMLParser(); 
     String xml = parser.getXmlFromUrl(URL); // getting XML from URL 
     Document doc = parser.getDomElement(xml); // getting DOM element 

     NodeList nl = doc.getElementsByTagName(KEY_SONG); 
     // looping through all song nodes <song> 
     for (int i = 0; i < nl.getLength(); i++) { 
      // creating new HashMap 
      HashMap<String, String> map = new HashMap<String, String>(); 
      Element e = (Element) nl.item(i); 
      // adding each child node to HashMap key => value 
      map.put(KEY_ID, parser.getValue(e, KEY_ID)); 
      map.put(KEY_TITLE, parser.getValue(e, KEY_TITLE)); 
      map.put(KEY_ARTIST, parser.getValue(e, KEY_ARTIST)); 
      map.put(KEY_DURATION, parser.getValue(e, KEY_DURATION)); 
      map.put(KEY_THUMB_URL, parser.getValue(e, KEY_THUMB_URL)); 

      // adding HashList to ArrayList 
      songsList.add(map); 
     } 


     list=(ListView)findViewById(R.id.list); 

     // Getting adapter by passing xml data ArrayList 
     adapter=new LazyAdapter(this, songsList);   
     list.setAdapter(adapter); 


     // Click event for single list row 
     list.setOnItemClickListener(new OnItemClickListener() { 

      @Override 
      public void onItemClick(AdapterView<?> parent, View view, 
        int position, long id) { 



       HashMap<String, String> resultp = new HashMap<String, String>(); 
        resultp = songsList.get(position); 
        String s_thumb=resultp.get(KEY_THUMB_URL); 
        String s_title=resultp.get(KEY_TITLE); 
        Intent intent = new Intent(CustomizedListView.this, SingleListItem_Attractions.class); 
        intent.putExtra("s_id", s_thumb); 
        intent.putExtra("s_title", s_title); 
        //other fields you want to send 
        startActivity(intent); 

      } 
     });  
    } 

這裏是我詳細的活動（單項）：

import android.app.Activity; 
import android.content.Context; 
import android.content.Intent; 
import android.graphics.Bitmap; 
import android.graphics.BitmapFactory; 
import android.net.Uri; 
import android.os.Bundle; 
import android.view.View; 
import android.view.View.OnClickListener; 
import android.widget.Button; 
import android.widget.TextView; 
import android.widget.ImageView; 

public class SingleListItem_Attractions extends Activity{ 
    Button button; 
    Button button2; 
    @Override 
    public void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     this.setContentView(R.layout.single_list_item_view); 


     ImageView imageView = (InageView) findViewById(R.id.imageView1); 
     Intent i2 = getIntent(); 
     String text2 =i2.getStringExtra("s_thumb"); 
     imageView.setImageBitmap(text2); 


     TextView texts = (TextView) findViewById(R.id.textView1); 
     Intent i = getIntent(); 

     String text1 =i.getStringExtra("s_title"); 

     texts.setText(text1); 

     addListenerOnButton(); 

    } 

    public void addListenerOnButton() { 

     final Context context = this; 

     button = (Button) findViewById(R.id.button1); 
     button2 = (Button) findViewById(R.id.button2); 
     button.setOnClickListener(new OnClickListener() { 

     @Override 
     public void onClick(View arg0) { 

     Intent intent = new Intent(context, CustomizedListView.class); 
     startActivity(intent); 

     } 





     }); 

     button2.setOnClickListener(new OnClickListener() { 

      @Override 
      public void onClick(View arg0) { 

      Intent intent = new Intent(context, CustomizedListView.class); 
      startActivity(intent); 

      } 





      });       

} 
} 

的問題在於ImageView的努力是由一個字符串設置即text2。 從text2中的url字符串設置imageview的正確方法是什麼？ 在此先感謝！

Answer 1

可以使用凌空庫這裏看看https://developer.android.com/training/volley/index.html

首先在你的gradle這個

dependencies { 
... 
compile 'com.android.volley:volley:1.0.0' 
} 

然後創建一個請求隊列

RequestQueue queue = Volley.newRequestQueue(this); 

然後創建一個ImageRequest

ImageRequest request = new ImageRequest(yourUrl, new Response.Listener<Bitmap>() { 
     @Override 
     public void onResponse(Bitmap response) { 
      imageView.setImageBitmap(response); 
     } 
    }, 0, 0, null, new Response.ErrorListener() { 
     @Override 
     public void onErrorResponse(VolleyError error) { 
      Log.e(TAG, error.toString(); 
     } 
    }); 

添加請求隊列

queue.add(request); 

Answer 2

使用通用圖像裝載機從URL設置圖像的ImageView。檢查這個Universal Image Loader

Answer 3

用戶畢加索庫：

compile 'com.squareup.picasso:picasso:2.5.2' 

和使用意圖通過圖像的URL，並與畢加索庫像貝洛奧裏藏特碼設置圖像中的ImageView：

Picasso.with(context) 
    .load(url) 
    .resize(50, 50) 
    .centerCrop() 
    .into(imageView) 

Answer 4

您可以使用第三方庫快速和可靠的方式來顯示圖像通過網址。

我建議滑翔： https://github.com/bumptech/glide

在上面的鏈接，你應該關心的部分下載和如何使用滑翔？將Glide包含在您的項目中並使用它。

所有在您詳細的活動（單項）加載圖像的所有最終代碼應該是這個樣子：

Glide 
.with(getContext()) 
.load(text2) 
.into(imageView); 

滑翔（以及其他圖像庫）將爲你提供許多方法用於自定義圖像（例如縮放，調整大小）。請參閱文檔。