我正在使用contacts project from AndroidHive的修改版本。
它基本上只是从Joomla网站上提取文章列表及其联系方式。
我正在使用Image Plugin从网址获取图片。我可以在文章详细活动视图上成功使用它，但我不知道如何将它添加到MainAcitivity文件上的每个列表项。我是Android开发的新手，请原谅我的混乱。
添加图片的脚本是：
ImageView thumb = (ImageView) findViewById(R.id.thumb);
UrlImageViewHelper.setUrlDrawable(thumb, "https://www.site.co.za/test.png");
和我生成ListView的MainActivity：
public class MainActivity extends ListActivity {
private ProgressDialog pDialog;
// URL to get articles JSON
private static String url = "http://192.168.12.21/sebastian/broadcast/index.php/blog?format=json";
// JSON Node names
private static final String TAG_ARTICLES = "articles";
// Get the fields
private static final String TAG_ID = "id";
private static final String TAG_TITLE = "title";
private static final String TAG_SHORTTEXT = "shorttext";
private static final String TAG_FULLTEXT = "fulltext";
private static final String TAG_IMAGE = "image";
private static final String TAG_DATE = "date";
// articles JSONArray
JSONArray articles = null;
// Hashmap for ListView
ArrayList<HashMap<String, String>> articleList;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
articleList = new ArrayList<HashMap<String, String>>();
ListView lv = getListView();
// Listview on item click listener
lv.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
// getting values from selected ListItem
String title = ((TextView) view.findViewById(R.id.title)).getText().toString();
String shorttext = ((TextView) view.findViewById(R.id.shorttext)).getText().toString();
String fulltext = ((TextView) view.findViewById(R.id.fulltext)).getText().toString();
String image = ((TextView) view.findViewById(R.id.image)).getText().toString();
String date = ((TextView) view.findViewById(R.id.date)).getText().toString();
// Starting single article activity
Intent in = new Intent(getApplicationContext(),
SingleArticleActivity.class);
in.putExtra(TAG_TITLE, title);
in.putExtra(TAG_SHORTTEXT, shorttext);
in.putExtra(TAG_FULLTEXT, fulltext);
in.putExtra(TAG_IMAGE, image);
in.putExtra(TAG_DATE, date);
startActivity(in);
}
});
// Calling async task to get json
new GetArticles().execute();
}
/**
* Async task class to get json by making HTTP call
* */
private class GetArticles extends AsyncTask<Void, Void, Void> {
@Override
protected void onPreExecute() {
super.onPreExecute();
// Showing progress dialog
pDialog = new ProgressDialog(MainActivity.this);
pDialog.setMessage("Please wait...");
pDialog.setCancelable(false);
pDialog.show();
}
@Override
protected Void doInBackground(Void... arg0) {
// Creating service handler class instance
ServiceHandler sh = new ServiceHandler();
// Making a request to url and getting response
String jsonStr = sh.makeServiceCall(url, ServiceHandler.GET);
Log.d("Response: ", "> " + jsonStr);
if (jsonStr != null) {
try {
JSONObject jsonObj = new JSONObject(jsonStr);
// Getting JSON Array node
articles = jsonObj.getJSONArray(TAG_ARTICLES);
// looping through All articles
for (int i = 0; i < articles.length(); i++) {
JSONObject c = articles.getJSONObject(i);
String id = c.getString(TAG_ID);
String title = c.getString(TAG_TITLE);
String shorttext = c.getString(TAG_SHORTTEXT);
String fulltext = c.getString(TAG_FULLTEXT);
String image = c.getString(TAG_IMAGE);
String date = c.getString(TAG_DATE);
// tmp hashmap for single article
HashMap<String, String> article = new HashMap<String, String>();
// adding each child node to HashMap key => value
article.put(TAG_ID, id);
article.put(TAG_TITLE, title);
article.put(TAG_SHORTTEXT, shorttext);
article.put(TAG_FULLTEXT, fulltext);
article.put(TAG_IMAGE, image);
article.put(TAG_DATE, date);
// adding article to article list
articleList.add(article);
}
} catch (JSONException e) {
e.printStackTrace();
}
} else {
Log.e("ServiceHandler", "Couldn't get any data from the url");
}
return null;
}
@Override
protected void onPostExecute(Void result) {
super.onPostExecute(result);
// Dismiss the progress dialog
if (pDialog.isShowing())
pDialog.dismiss();
/**
* Updating parsed JSON data into ListView
* */
ListAdapter adapter = new SimpleAdapter(
MainActivity.this, articleList,
R.layout.list_item, new String[] {
TAG_TITLE,
TAG_SHORTTEXT,
TAG_FULLTEXT,
TAG_IMAGE,
TAG_DATE
},
new int[] {
R.id.title,
R.id.shorttext,
R.id.fulltext,
R.id.image,
R.id.date
});
setListAdapter(adapter);
}
}
}
**我不知道在MainActivity文件中我添加脚本以向每个列表项添加图像。
我已经让它在SingleArticleActivity上工作了，但无法让它在项目列表上工作**
感谢您的帮助
更新
我想做什么：
foreach(ListItem in the List) {
ImageView thumb = (ImageView) findViewById(R.id.thumb);
UrlImageViewHelper.setUrlDrawable(thumb, "https://www.site.co.za/test.png");
}
答案 0 :(得分：0)
我在我的ListView适配器的getView方法中使用此方法，该方法返回一个drawable，我稍后将其设置为我的ImageView。
public Drawable LoadImageFromWebOperations(String url) {
try {
InputStream is = (InputStream) new URL(url).getContent();
Drawable d = Drawable.createFromStream(is, "src name");
return d;
} catch (Exception e) {
return default_image;
}
}
希望这有帮助。
答案 1 :(得分：0)
你必须使用这个......
ImageView thumb = (ImageView) findViewById(R.id.thumb);
UrlImageViewHelper.setUrlDrawable(thumb, articleList.get(position).get(TAG_IMAGE));
CustomAdapter cdp = new CustomAdapter(YourActivityName.this , articleList);
setListAdapter(adapter);
现在，使用 BaseAdapter 扩展 CustomAdapter 类
public class CustomAdapter extends BaseAdapter {
ArrayList<HashMap<String, String>> list;
Context ctx;
public CustomAdapter(Context c , ArrayList<HashMap<String, String>> articleList){
this.ctx = c;
this.list = articleList;
}
@Override
public int getCount() {
return list.size();
}
@Override
public Object getItem(int position) {
return null;
}
@Override
public long getItemId(int position) {
return position;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
final ViewHolder holder;
View view = convertView;
if (view == null) {
view = getLayoutInflater().inflate(R.layout.list_item,
parent, false);
holder = new ViewHolder();
assert view != null;
holder.imageView = (ImageView) view.findViewById(R.id.image);
view.setTag(holder);
} else {
holder = (ViewHolder) view.getTag();
}
UrlImageViewHelper.setUrlDrawable(thumb, articleList.get(position).get(TAG_IMAGE));
return view;
}
class ViewHolder {
ImageView imageView;
}
}
答案 2 :(得分：0)
试用此功能强大的Android Picasso
图像下载和缓存库图像为Android应用程序添加了急需的上下文和视觉风格。 Picasso允许在您的应用程序中轻松加载图像 - 通常只需一行代码！
Picasso.with(context).load("http://i.imgur.com/DvpvklR.png").into(imageView);