我想显示来自网址的图片，这些网址是从mysql数据库中收到的，还有其他信息，如用户名，帖子标题和消息。我已经设法做到这一点，从数据库收到网址并在帖子中显示为文本。
现在我将类型从textview更改为imageview：
<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/url"
android:layout_gravity="center_horizontal" />
我不知道如何继续。
这是我的代码：
public class ReadComments extends ListActivity {
// Progress Dialog
private ProgressDialog pDialog;
//php read comments script
//localhost :
//testing on your device
//put your local ip instead, on windows, run CMD > ipconfig
//or in mac's terminal type ifconfig and look for the ip under en0 or en1
// private static final String READ_COMMENTS_URL = "http://xxx.xxx.x.x:1234/webservice/comments.php";
//testing on Emulator:
private static final String READ_COMMENTS_URL = "http://www.eywow.com/webservice/comments.php";
//testing from a real server:
//private static final String READ_COMMENTS_URL = "http://www.mybringback.com/webservice/comments.php";
//JSON IDS:
private static final String TAG_SUCCESS = "success";
private static final String TAG_TITLE = "title";
private static final String TAG_POSTS = "posts";
private static final String TAG_POST_ID = "post_id";
private static final String TAG_USERNAME = "username";
private static final String TAG_MESSAGE = "message";
private static final String TAG_URL = "url";
//it's important to note that the message is both in the parent branch of
//our JSON tree that displays a "Post Available" or a "No Post Available" message,
//and there is also a message for each individual post, listed under the "posts"
//category, that displays what the user typed as their message.
//An array of all of our comments
private JSONArray mComments = null;
//manages all of our comments in a list.
private ArrayList<HashMap<String, String>> mCommentList;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
//note that use read_comments.xml instead of our single_post.xml
setContentView(R.layout.read_comments);
}
@Override
protected void onResume() {
// TODO Auto-generated method stub
super.onResume();
//loading the comments via AsyncTask
new LoadComments().execute();
}
public void addComment(View v)
{
Intent i = new Intent(ReadComments.this, AddComment.class);
startActivity(i);
}
public void startButton(View v)
{
Intent a = new Intent(ReadComments.this, UploadToServer.class);
startActivity(a);
}
/**
* Retrieves recent post data from the server.
*/
public void updateJSONdata() {
// Instantiate the arraylist to contain all the JSON data.
// we are going to use a bunch of key-value pairs, referring
// to the json element name, and the content, for example,
// message it the tag, and "I'm awesome" as the content..
mCommentList = new ArrayList<HashMap<String, String>>();
// Bro, it's time to power up the J parser
JSONParser jParser = new JSONParser();
// Feed the beast our comments url, and it spits us
//back a JSON object. Boo-yeah Jerome.
JSONObject json = jParser.getJSONFromUrl(READ_COMMENTS_URL);
//when parsing JSON stuff, we should probably
//try to catch any exceptions:
try {
//I know I said we would check if "Posts were Avail." (success==1)
//before we tried to read the individual posts, but I lied...
//mComments will tell us how many "posts" or comments are
//available
mComments = json.getJSONArray(TAG_POSTS);
// looping through all posts according to the json object returned
for (int i = 0; i < mComments.length(); i++) {
JSONObject c = mComments.getJSONObject(i);
//gets the content of each tag
String title = c.getString(TAG_TITLE);
String content = c.getString(TAG_MESSAGE);
String username = c.getString(TAG_USERNAME);
String url = c.getString(TAG_URL);
// creating new HashMap
HashMap<String, String> map = new HashMap<String, String>();
map.put(TAG_TITLE, title);
map.put(TAG_MESSAGE, content);
map.put(TAG_USERNAME, username);
map.put(TAG_URL, url);
// adding HashList to ArrayList
mCommentList.add(map);
//annndddd, our JSON data is up to date same with our array list
}
} catch (JSONException e) {
e.printStackTrace();
}
}
/**
* Inserts the parsed data into the listview.
*/
private void updateList() {
// For a ListActivity we need to set the List Adapter, and in order to do
//that, we need to create a ListAdapter. This SimpleAdapter,
//will utilize our updated Hashmapped ArrayList,
//use our single_post xml template for each item in our list,
//and place the appropriate info from the list to the
//correct GUI id. Order is important here.
ListAdapter adapter = new SimpleAdapter(this, mCommentList,
R.layout.single_post, new String[] { TAG_TITLE, TAG_MESSAGE,
TAG_USERNAME, TAG_URL }, new int[] { R.id.title, R.id.message,
R.id.username, R.id.url });
// I shouldn't have to comment on this one:
setListAdapter(adapter);
// Optional: when the user clicks a list item we
//could do something. However, we will choose
//to do nothing...
ListView lv = getListView();
lv.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
// This method is triggered if an item is click within our
// list. For our example we won't be using this, but
// it is useful to know in real life applications.
}
});
}
class PostLike{
}
public class LoadComments extends AsyncTask<Void, Void, Boolean> {
@Override
protected void onPreExecute() {
super.onPreExecute();
pDialog = new ProgressDialog(ReadComments.this);
pDialog.setMessage("Loading Comments...");
pDialog.setIndeterminate(false);
pDialog.setCancelable(true);
pDialog.show();
}
@Override
protected Boolean doInBackground(Void... arg0) {
//we will develop this method in version 2
updateJSONdata();
return null;
}
@Override
protected void onPostExecute(Boolean result) {
super.onPostExecute(result);
pDialog.dismiss();
//we will develop this method in version 2
updateList();
}
}
}
答案 0 :(得分：1)
有很多方法，但是这个库可以让你的工作变得轻松：
单击Picasso并阅读文档，非常简单，您只需编写一行代码：
Picasso.with(context).load("http://i.imgur.com/DvpvklR.png").into(imageView);
但请在下次提出问题时提供简洁明了的代码。 祝你好运。
在你的情况下：
String url = "...";
ImageView imageView = (ImageView) findViewById(R.id.url);
Picasso.with(context).load(url).into(imageView);
但请确保下载JAR文件并将其包含在项目中，除非此代码不起作用。
答案 1 :(得分：0)
好的我添加了它并包含了.jar但是它不起作用，应用程序崩溃了，我认为这是解决这个问题的相关部分：
try {
mComments = json.getJSONArray(TAG_POSTS);
// looping through all posts according to the json object returned
for (int i = 0; i < mComments.length(); i++) {
JSONObject c = mComments.getJSONObject(i);
//gets the content of each tag
String title = c.getString(TAG_TITLE);
String content = c.getString(TAG_MESSAGE);
String username = c.getString(TAG_USERNAME);
String url = c.getString(TAG_URL);
// creating new HashMap
HashMap<String, String> map = new HashMap<String, String>();
map.put(TAG_TITLE, title);
map.put(TAG_MESSAGE, content);
map.put(TAG_USERNAME, username);
map.put(TAG_URL, url);
// PART TO GET IMAGES - "Can not resolve context"
ImageView imageView = (ImageView) findViewById(R.id.url);
Picasso.with(context).load(url).into(imageView);
// adding HashList to ArrayList
mCommentList.add(map);
//annndddd, our JSON data is up to date same with our array list
}
修改
当我开始构建应用程序时，我创建了2个帖子，其中包含图像的直接文件路径，它们存储在设备中，显示正确： Screenshot
上传的图片没有显示，他们有这样的网址：
