问题
I have a Custom Listview that it is updated from a EditText component in a dialog. I have the custom row, the adapter class and the custom dialog all working but I can't seem to trigger the code in the adatper class that would add the text from the edit text control to the list. Here is my activity code, let me know if you want the adapter code. It worked before I added the custom row and adapter to the list :(
Symptom of problem: emailAdapter.notifyDataSetChanged(); does nothing
public class InvitePlayers_Activity extends Activity {
ListViewAdapter emailAdapter = null;
ImageView imgView_mail;
ImageView imgView_confirm;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
this.requestWindowFeature(Window.FEATURE_NO_TITLE); //remove title bar
setContentView(R.layout.activity_inviteplayers);
//Generate list View from ArrayList
displayListView();
}
private void displayListView() {
//assign controls
final ListView listView = (ListView) findViewById(R.id.listView_invitePlayers);
imgView_mail = (ImageView)findViewById(R.id.imgView_mail);
//Test data
ArrayList<String> inviteNew = new ArrayList<String>();
final ArrayList<ArrayList<String>> inviteList = new ArrayList<ArrayList<String>>();
emailAdapter = new ListViewAdapter(this,inviteList);
listView.setAdapter(emailAdapter);
// Assign adapter to ListView
listView.setTextFilterEnabled(true);
//Edit listeners
imgView_mail.setOnClickListener(new View.OnClickListener() {
public void onClick(View view)
{
//variables
final String enteredMail = "testListViewEntry";
final ArrayList<ArrayList<String>> inviteList = new ArrayList<ArrayList<String>>();
ArrayList<String> invite = new ArrayList<String>();
invite.add(0, enteredMail);//add first email
invite.add(1,"icon_invitestatussent.png"); //add first status icon
inviteList.add(invite);
emailAdapter.notifyDataSetChanged();
listView.setAdapter(emailAdapter);
}
});
}
}
Adapter code as requested
public class ListViewAdapter extends BaseAdapter {
private Activity context;
ArrayList<ArrayList<String>> inviteDetails = new ArrayList<ArrayList<String>>();
public ListViewAdapter(Activity context, ArrayList<ArrayList<String>> inviteDetails ) {
this.inviteDetails = inviteDetails;
this.context = context;
}
@Override
public int getCount() {
return inviteDetails.size();
}
@Override
public Object getItem(int i) {
return inviteDetails.get(i).get(0);
}
@Override
public long getItemId(int i) {
return i;
}
public View getView(int position, View view, ViewGroup parent){
//Inflater
LayoutInflater inflater = context.getLayoutInflater();
//get row view
if (view == null) {
LayoutInflater mInflater = (LayoutInflater)
context.getSystemService(Activity.LAYOUT_INFLATER_SERVICE);
view = mInflater.inflate(R.layout.list_item_email, null);
}
//assign controls
final TextView textView_playerEmail = (TextView) view.findViewById(R.id.textView_playerEmail);
ImageView imgView_inviteStatus = (ImageView) view.findViewById(R.id.imgView_inviteStatus);
//Assign control values that are dynamic
textView_playerEmail.setText(inviteDetails.get(position).get(0));
imgView_inviteStatus.setImageResource(R.drawable.icon_invitestatussent);
return view;
}
@Override
public void notifyDataSetChanged() {
super.notifyDataSetChanged();
}
}
Custom row xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="horizontal"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:padding="10dp"
android:textSize="16sp"
android:id="@+id/textView_playerEmail"
android:textColor="@color/white"
android:text="item1">
</TextView>
<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/imgView_inviteStatus" />
<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/imgView_remove"
android:src="@drawable/btn_cancel" />
</LinearLayout>
The activity layout
<LinearLayout
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_weight="20"
android:background="@color/yellow"
android:layout_margin="20dp"
android:padding="5dp">
<LinearLayout
android:orientation="horizontal"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:weightSum="1"
android:gravity="left|center">
<ImageView
android:layout_width="45dp"
android:layout_height="34dp"
android:id="@+id/imgView_mail"
android:src="@drawable/btn_mail"
android:layout_weight="0.22"
android:padding="3dp" />
</LinearLayout>
<ListView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/listView_invitePlayers"
android:layout_gravity="center_horizontal" />
</LinearLayout>
<ImageView
android:layout_width="80dp"
android:layout_height="80dp"
android:id="@+id/btn_confirm"
android:src="@drawable/btn_confirm"
android:clickable="false"
android:adjustViewBounds="true"
android:layout_gravity="center_horizontal"
android:padding="2dp"
android:layout_weight="1" />
</LinearLayout>
</FrameLayout>
回答1:
Well, for what we discussed, you wanted something like this:
When you want to make a custom ListView, you have to write your own adapter. In this particular case I'm subclassing the BaseAdapter class.
This custom adapter will take hold of my data model, and will inflate the data to my ListView rows.
First, I'll create the XML of my custom row. You can see the code below.
item_mail.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Test text"
android:id="@+id/tv_mail"
android:layout_alignParentTop="true"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true"
android:layout_centerVertical="true"/>
<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/iv_icon"
android:layout_alignParentTop="true"
android:layout_alignParentEnd="true"
android:layout_alignParentRight="true"
android:layout_centerVertical="true"
android:src="@android:drawable/ic_menu_report_image" />
</RelativeLayout>
Here I've created a row that displays a text and an image.
Now, I'll create my custom adapter to handle this XML. As you can see below.
MailAdapter.java
public class MailAdapter extends BaseAdapter {
private static final String LOG_TAG = MailAdapter.class.getSimpleName();
private Context context_;
private ArrayList<ArrayList<String>> mailitems;
public MailAdapter(Context context, ArrayList<ArrayList<String>> mailitems) {
this.context_ = context;
this.mailitems = mailitems;
}
@Override
public int getCount() {
return mailitems.size();
}
@Override
public Object getItem(int position) {
return mailitems.get(position).get(0);
}
@Override
public long getItemId(int position) {
return position;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
if (convertView == null) {
LayoutInflater mInflater = (LayoutInflater)
context_.getSystemService(Activity.LAYOUT_INFLATER_SERVICE);
convertView = mInflater.inflate(R.layout.item_mail, null);
}
TextView tv_mail = (TextView) convertView.findViewById(R.id.tv_mail);
ImageView iv_icon = (ImageView) convertView.findViewById(R.id.iv_icon);
String mail = mailitems.get(position).get(0);
String icon = mailitems.get(position).get(1);
Log.d(LOG_TAG,"Mail: " + mail + " mail_icon: " + icon);
tv_mail.setText(mail);
// iv_icon.setImageURI(); Here you can do whatever logic you want to update your image, using URI's, ID's, or something else.
return convertView;
}
}
Ok. Now we have everything to make this work. In your Activity class, do something like that:
activity_main.xml
<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" android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:paddingBottom="@dimen/activity_vertical_margin" tools:context=".MainActivity">
<TextView
android:text="@string/hello_world"
android:id="@+id/tv_header"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true" />
<LinearLayout
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_below="@+id/tv_header">
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Add mail"
android:id="@+id/button"
android:layout_gravity="center" />
<ListView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/listView" />
</LinearLayout>
</RelativeLayout>
MainActivity.java
public class MainActivity extends ActionBarActivity {
private int numMail = 1; // Dummy int to create my items with different numbers.
private MailAdapter mailAdapter; // Your custom adapter.
private ArrayList<ArrayList<String>> mailItems; // This is going to be your data structure, everytime you change it, call the notifyDataSetChanged() method.
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button bt = (Button) findViewById(R.id.button);
ListView lv_mail = (ListView) findViewById(R.id.listView);
mailItems = new ArrayList<>();
mailAdapter = new MailAdapter(this,mailItems);
lv_mail.setAdapter(mailAdapter);
bt.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
addItem(); // The method I'm using to insert the item. Look for it below.
}
});
}
// Here I'm creating a new ArrayList, and appending it to my 'mailItems' Array. After that, I'm notifying the adapter that my data changed.
private void addItem() {
ArrayList<String> mail = new ArrayList<>();
mail.add(0,"mail " + numMail++);
mail.add(1,"path_to_image"); // Depending on what you want to do, put your path, URI, or whatever other way you want to store that image data.
mailItems.add(mail); // Inserting the data on the ArrayList.
mailAdapter.notifyDataSetChanged(); // Notifying the adapter that my ArrayList was modified.
}
}
This should do the trick.
I guess your problem was that you weren't updating the same ArrayList that was in your custom adapter. That's why when you called notifyDataSetChanged()nothing happened, I mean. You were creating a new ArrayList, which wasn't the same that was in your adapter. So here's what I did... I've made the ArrayList global, and then I've used it in my custom adapter constructor. After that, when the user triggers the onClick() method of my button, I'm inserting some new data on my global Array, and then I'm notifying the adapter that the data changed.
You can read a little more about that here and I've found a similar question here, which you can read as well.
Edit: Another related question, which might be an interesting read.
来源：https://stackoverflow.com/questions/30462112/listview-updated-from-edittext