How do I display a single item in a new activity from a ListView of multiple items (Android)
If you have any knowledge of ListViews/RSS feeds/Android programming in general, please take a quick look at this question. Thanks!
I have a ListView of multiple items(messages) that are listed in my NewsActivity as follows:
public class NewsActivity extends ListActivity {
private List<Message> messages;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.news);
loadFeed();
}
private void loadFeed(){
try{
BaseFeedParser parser = new BaseFeedParser();
messages = parser.parse();
List<String> titles = new ArrayList<String>(messages.size());
List<String> descriptions = new ArrayList<String>(messages.size());
List<String> dates = new ArrayList<String>(messages.size());
for (Message msg : messages){
titles.add(msg.getTitle());
descriptions.add(msg.getDescription());
dates.add(msg.getDate());
}
ArrayAdapter<String> adapter =
new ArrayAdapter<String>(this, R.layout.row,titles);
this.setListAdapter(adapter);
} catch (Throwable t){
Log.e("AndroidNews",t.getMessage(),t);
}
}
@Override
protected void onListItemClick(ListView l, View v, int position, long id) {
super.onListItemClick(l, v, position, id);
Intent i = new Intent(this, RSSItem.class);
//id = the id of the item clicked
startActivityForResult(i, 1);
int count = 0;
for (Message msg : messages) {
if(count == id){
//This is obviously not how it should be done.
//But my idea here is that I need to pass the msg to the new RSSItem class.
RSSItem item = new RSSItem(msg);
}
count++;
}
}
}
This NewsActivity displays my ListView of the titles of each message. The part I need help with is the last function onListItemClick. The function creates a new RSSItem Activity. I just need to display the title, date, and description of that item(which are all currently saved in Lists) in this new activity. Here is what I have so far for the RSSItem class:
public class RSSItem extends Activity {
private Message rssItem;
private String title;
private String date;
private 开发者_如何学JAVAString description;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.rssitem);
}
public RSSItem(){
//default constructor: must have 0 arguments
}
public RSSItem(Message msg){
rssItem = msg;
title = rssItem.getTitle();
date = rssItem.getDate();
description = rssItem.getDescription();
}
}
So... currently, RSSItem gets the message from the NewsActivity, and saves the title, date, and description. If this should be done in a better/different way, please let me know.
Now I just need to display this information(title, date, description) in this new RSSItem Activity. However, I am not exactly sure how this works/how to do it. Is it completely determined by the R.layout.rssitem file? Here is my R.layout.rssitem file:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent">
<LinearLayout android:orientation="horizontal"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<TextView android:id="@+id/title"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="1" />
</LinearLayout>
<TextView android:id="@+id/description" android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_weight="1"
android:scrollbars="vertical" />
</LinearLayout>
Currently, the RSSItem Activity doesn't display anything. Any help would be greatly appreciated!!
Usually the easiest thing to do is to add extra's to your Intent before calling startActivity.
Intent i = new Intent(this, RSSItem.class);
//pardon the gross use of fields and key names.
//you would pass in the selected item's fields, more than likely using
//its position, not id
i.putExtra("title", title);
i.putExtra("description", description);
i.putExtra("date", date);
startActivityForResult(i, 1);
Then in your onCreate() in the RSSItem Activity, you can retrieve that intent by
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.rssitem);
Intent receivedIntent = this.getIntent();
//and pick up the extras
title = receivedIntent.getStringExtra("title");
//and so on...
//instantiate views...
TextView titleView = (TextView) findViewById(R.id.title);
titleView.setText(title);
}
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