【发布时间】：2021-01-02 17:40:43
【问题描述】：
我为我的 Android 应用创建了一个自定义列表视图，以便为每个单元格添加一个删除按钮，使用户能够从列表中删除行。自定义列表视图运行良好，但是当我为按钮添加单击侦听器时，列表视图显示空单元格，而不是填充来自数组的数据。 这是getView的代码：
public View getView(final int position, View convertView, ViewGroup parent) {
LayoutInflater inflater = getLayoutInflater();
View row = inflater.inflate(R.layout.row, parent, false);
Button deleteButt = (Button) row.findViewById(R.id.deleteButton);
deleteButt.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Toast.makeText(getActivity(), "delete me", Toast.LENGTH_SHORT).show();
}
});
return row;
}
我认为我应该返回其他东西而不是行，但我不知道要返回什么。当我考虑返回行时，它应该显示填充了数据的行。请注意，当我删除这段代码时，列表视图可以很好地显示数据。
这是适配器类的全部代码
// Our adapter class
class MyAdapter extends ArrayAdapter<String> {
Context context;
String rNames[];
MyAdapter(Context c, String name[]) {
super(c, R.layout.row, R.id.customerName, name);
this.context = c;
this.rNames = name;
}
public View getView(final int position, View convertView, ViewGroup parent) {
LayoutInflater inflater = getLayoutInflater();
View row = inflater.inflate(R.layout.row, parent, false);
Button deleteButt = (Button) row.findViewById(R.id.deleteButton);
deleteButt.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Toast.makeText(getActivity(), "delete me", Toast.LENGTH_SHORT).show();
}
});
return row;
}
}
这是首页片段页面的全部代码
public class HomeFragment extends Fragment {
// creating an empty array. This is an array of objects (array of arrays).
final ArrayList<String[]> mainObjectsArray = new ArrayList<String[]>();
//final String[][] myFamily = new String[][];
// creating another array of the titles. If our main array is an array of strings we will not need this.
// Why?. ArrayAdapter doesn't accept an array of arrays it only accepts an array of Stings, so we had to create a special array for the titles and bring them from our main array.
final ArrayList<String> theNames = new ArrayList<String>();
@Nullable
@Override
public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
final View rootView = inflater.inflate(R.layout.fragment_home, null);
// creaing a list view and connect it to the list view we created in the XML file
// Note: we need to add (final) to be able to access them from inside the loop
final ListView myListView = (ListView) rootView.findViewById(R.id.myListView);
// Retrieving the data and filling the array with it
ParseQuery<ParseObject> query = ParseQuery.getQuery("Orders");
query.orderByDescending("updatedAt");
query.findInBackground(new FindCallback<ParseObject>() {
@Override
public void done(List<ParseObject> objects, ParseException e) {
if (e == null) {
//Log.i("findInBackground", "Retrieved: " + objects.size() + "objects");
if (objects.size() > 0) {
for (ParseObject object: objects) {
// Converting every object to an array of two itmes, title and body.
String[] artical = {object.getString("TheSavedOrder"), object.getString("mobileNumber"), object.getString("Name")};
// Adding the array to our main array so we will have an array of arrays
mainObjectsArray.add(artical);
//Log.i("This my family array: ", myFamily.toString());
}
// We will add only the names to the array (theNames). theTitles will be an array of strings so we can populate it in the list view.
for (int i = 0; i < mainObjectsArray.size(); i++){
theNames.add(mainObjectsArray.get(i)[2]);
//Log.i("Here are teh title: ", myFamily.get(i)[0]);
Log.i("Here is thti: ", theNames.get(i));
}
// Converting theNames from ArrayList to an array
String[] namesArray = new String[theNames.size()];
namesArray = theNames.toArray(namesArray);
// Applaying our adapter
MyAdapter adapter = new MyAdapter(getActivity(), namesArray);
myListView.setAdapter(adapter);
}
}
}
});
// When clicking on an item in the list view
myListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
//Log.i("The body is: ", mainObjectsArray.get(position));
Intent intent = new Intent(getContext(), TheBody.class);
intent.putExtra("mobile", mainObjectsArray.get(position)[1]); // mainObjectsArray.get(position)[1] means we will pass the second item in every array which is the (mobileNumber).
intent.putExtra("order", mainObjectsArray.get(position)[0]);
startActivity(intent);
}
});
return rootView;
}
// Our adapter class
class MyAdapter extends ArrayAdapter<String> {
Context context;
String rNames[];
MyAdapter(Context c, String name[]) {
super(c, R.layout.row, R.id.customerName, name);
this.context = c;
this.rNames = name;
}
public View getView(final int position, View convertView, ViewGroup parent) {
LayoutInflater inflater = getLayoutInflater();
View row = inflater.inflate(R.layout.row, parent, false);
Button deleteButt = (Button) row.findViewById(R.id.deleteButton);
deleteButt.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Toast.makeText(getActivity(), "delete me", Toast.LENGTH_SHORT).show();
}
});
return row;
}
}
}
这是片段的 XML 代码
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<ListView
android:id="@+id/myListView"
android:layout_width="match_parent"
android:layout_height="match_parent" />
</LinearLayout>
最后这是自定义单元格的 XML 代码
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal"
android:padding="16dp"
android:descendantFocusability="blocksDescendants">
<TextView
android:id="@+id/customerName"
android:layout_width="200dp"
android:layout_height="wrap_content"
android:text="custoemr name"
android:textColor="#000"
android:layout_margin="5dp"
android:textSize="20sp"/>
<Button
android:id="@+id/deleteButton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Delete"
/>
</LinearLayout>
请帮助我已经为此苦苦挣扎了几天！ 非常感谢。
【问题讨论】：
标签： java android listview android-fragments