问题
I have stumbled upon a problem I can't quite get my head around, so I was hoping perhaps someone here have had the same problem or knew a good way of solving the problem.
I have created a view containing a ListView. This ListView contains two TextView. The problem is that I don't know where I send the values which are meant to go in the second text view using the ArrayAdapter. Is there a way to send with more information to the ArrayAdapter so that I can feed the "todaysmenu" TextView?
The ArrayAdapter method:
private void createList() {
ListView lv = (ListView) findViewById(R.id.mylist);
String[] values = new String[] { "Android", "Linux", "OSX",
"WebOS", "Windows7", "Ubuntu", "OS/2"
};
ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,R.layout.rowlayout, R.id.restaurantname, values);
lv.setAdapter(adapter);
}
The row markup:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="vertical" >
<TextView
android:id="@+id/restaurantname"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@+id/restaurantname"
android:textSize="23dp" >
</TextView>
<TextView
android:id="@+id/textView1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="@+id/todaysmenu" />
</LinearLayout>
The activity layout:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<ListView
android:id="@+id/mylist"
android:layout_width="match_parent"
android:layout_height="wrap_content">
</ListView>
</LinearLayout>
At the beginning I got everything to work, but when I added the second textfield problems arouse. In advance, thank you for your help!
回答1:
To achieve this you have to build a custom adapter and inflate your custom row layout. Using ArrayAdapter won't work because
By default this class expects that the provided resource id references a single TextView. If you want to use a more complex layout, use the constructors that also takes a field id. That field id should reference a TextView in the larger layout resource.
So, your custom adapter class could be somthing like:
public class CustomAdapter extends ArrayAdapter {
private final Activity activity;
private final List list;
public CustomAdapter(Activity activity, ArrayList<Restaurants> list) {
this.activity = activity;
this.list = list;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
View rowView = convertView;
ViewHolder view;
if(rowView == null)
{
// Get a new instance of the row layout view
LayoutInflater inflater = activity.getLayoutInflater();
rowView = inflater.inflate(R.layout.rowlayout, null);
// Hold the view objects in an object, that way the don't need to be "re- finded"
view = new ViewHolder();
view.retaurant_name= (TextView) rowView.findViewById(R.id.restaurantname);
view.restaurant_address= (TextView) rowView.findViewById(R.id.textView1);
rowView.setTag(view);
} else {
view = (ViewHolder) rowView.getTag();
}
/** Set data to your Views. */
Restaurants item = list.get(position);
view.retaurant_name.setText(item.getTickerSymbol());
view.restaurant_address.setText(item.getQuote().toString());
return rowView;
}
protected static class ViewHolder{
protected TextView retaurant_name;
protected TextView restaurant_address;
}
}
And your Restaurant.java class could as simple as I describe below:
public class Restaurants {
private String name;
private String address;
public Restaurants(String name, String address) {
this.name = name;
this.address = address;
}
public void setName(String name) {
this.name= name;
}
public String getName() {
return name;
}
public void setAddress(String address) {
this.address= address;
}
public String getAddress() {
return address;
}
}
Now, in you main activity just bind you list with some data, like;
/** Declare and initialize list of Restaurants. */
ArrayList<Restaurants> list = new ArrayList<Restaurants>();
/** Add some restaurants to the list. */
list.add(new Restaurant("name1", "address1"));
list.add(new Restaurant("name2", "address2"));
list.add(new Restaurant("name3", "address3"));
list.add(new Restaurant("name4", "address4"));
list.add(new Restaurant("name5", "address5"));
list.add(new Restaurant("name6", "address6"));
At this point you're able to set the custom adapter to your list
ListView lv = (ListView) findViewById(R.id.mylist);
CustomAdapter adapter = new CustomAdapter(YourMainActivityName.this, list);
lv.setAdapter(adapter);
This is all and it should work nicelly, but I strongly recommend you to google for some better alternatives to implement others Adapters.
回答2:
You could try this https://devtut.wordpress.com/2011/06/09/custom-arrayadapter-for-a-listview-android/. You have to create a custom class Item with fields you need and extend ArrayAdapter .
回答3:
I think that your problem is here:
Instead of this:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="vertical" >
<TextView
android:id="@+id/restaurantname"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@+id/restaurantname"
android:textSize="23dp" >
</TextView>
<TextView
android:id="@+id/textView1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="@+id/todaysmenu" />
</LinearLayout>
Try something like this:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="vertical" >
<TextView
android:id="@+id/restaurantname"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="test text"
android:textSize="23dp" >
</TextView>
<TextView
android:id="@+id/textView1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="test text" />
</LinearLayout>
If that works, then place your text in the /res/val/string folder like so:
<string name="testText">Put your text here...</string>
and then call like this:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="vertical" >
<TextView
android:id="@+id/restaurantname"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/testText"
android:textSize="23dp" >
</TextView>
<TextView
android:id="@+id/textView1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="@string/testText" />
</LinearLayout>
You would then set the dynamic values like this:
TextView tv = (TextView)findViewById(R.id.restaurantname);
tv.setText(values);
回答4:
I had to solve the same problem and tried to use the arrayadapter as answered here above, but it didn't work.
Later I succeeded to do it with baseadapter -- this is the adapter:
public class BusinessAdapter2 extends BaseAdapter {
private final ArrayList<Business> myList;
LayoutInflater inflater;
Context context;
public BusinessAdapter2(Context context, ArrayList<Business> myList) {
this.myList = myList;
this.context = context;
inflater = LayoutInflater.from(this.context);
}
@Override
public int getCount() {
return myList.size();
}
@Override
public Object getItem(int position) {
return myList.get(position);
}
@Override
public long getItemId(int position) {
return 0;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
if (convertView==null) convertView = inflater.inflate(R.layout.business_list_item_2, parent, false);
// assign the view we are converting to a local variable
View v = convertView;
Business b = myList.get(position);
if (b != null) {
TextView name = (TextView) v.findViewById(R.id.textview_name);
TextView address = (TextView) v.findViewById(R.id.textview_address);
TextView description = (TextView) v.findViewById(R.id.textview_description);
TextView discount = (TextView) v.findViewById(R.id.textview_discount);
// check to see if each individual textview is null.
// if not, assign some text!
if (name != null){
name.setText(b.name);
}
if (address != null){
address.setText(b.address);
}
if (description != null){
description.setText(b.description);
}
if (discount != null){
discount.setText(b.discountRate);
}
}
// the view must be returned to our activity
return v;
}
}
this is the Object class I used (Business):
public class Business {
String name,address,description,discountRate;
public Business(){}
public Business(String name,String address,String description,String discountRate){
this.name=name;
this.address=address;
this.description=description;
this.discountRate=discountRate;
}
}
and this is how I populate the listview into the adapter:
ArrayList<Business> businesses2=new ArrayList<Business>(Arrays.asList(for_listview_objects));
adapter_objects =new BusinessAdapter2(
context, // The current context (this activity)
businesses2);
listView.setAdapter(adapter_objects);
来源：https://stackoverflow.com/questions/11678909/use-array-adapter-with-more-views-in-row-in-listview