我有一个自定义 SimpleCursorAdapter 和一个列表视图。列表的每一行都有一个名称和一个按钮。当我按下每个名称的按钮时，会出现一个带有描述的对话框。在自定义 SimpleCursorAdapter 中，我为按钮设置了 onclick 方法。当我有一个大列表时，我的 listView 会得到一个滚动条。而且我不知道为什么，当我向下滚动时，列表的最后一行没有显示每一行的正确描述。这是我的代码：
public class listServicesCursorAdapter extends SimpleCursorAdapter{
private Context context;
private int layout;
private String[] from;
private int[] to;
public listServicesCursorAdapter (Context context, int layout, Cursor c,
String[] from, int[] to, int flags) {
super(context, layout, c, from, to, flags);
this.context = context;
this.layout = layout;
this.from = from;
this.to = to;
}
@Override
public View newView(Context context, Cursor cursor, ViewGroup parent) {
final LayoutInflater inflater = LayoutInflater.from(context);
View v = inflater.inflate(layout, parent, false);
//Column of BD that we want to recover
String column = null;
//Index of the column of DB
int nameCol = 0;
//Result of obtain the index of the column of DB
String nombre = null;
//Name of the textView in the Layout where we want to show the result
TextView name_text= null;
String description = null;
String nameService = null;
//For each value of DB, we show it in the text view.
for (int i=0; i<from.length; i++){
column= from[i];
nameCol = cursor.getColumnIndex(column);
name = cursor.getString(nameCol);
//the values to[i] equals to 0 indicates values that we need but
//that we are not showing in the list directly
//0 -> description
if(to[i] == 0){
description = name;
}else{
nameService = name;
name_text = (TextView) v.findViewById(to[i]);
if (name_text != null) {
name_text.setText(name);
}
}
}
ImageButton buttonDescription = (ImageButton) v.findViewById(R.id.imageButtonDescription);
//we store in a bundle the name and description of the service, so we can use it in
// the setOnClickListener method.
final Bundle mArguments = new Bundle();
mArguments.putString("name", nameService);
mArguments.putString("description", description);
buttonDescription .setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v){
AlertDialog.Builder builder = new AlertDialog.Builder(v.getContext());
builder.setMessage(mArguments.getString("description"))
.setTitle(mArguments.getString("name"))
.setCancelable(false)
.setPositiveButton("Ok", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
dialog.cancel();
}
});
AlertDialog alert = builder.create();
alert.show();
}});
return v;
}
}
这是我调用适配器的地方：
ServiceSqliteDao serviceDao = new ServiceSqliteDao();
//get the services for DB
Cursor mCursorServices = serviceDao.listServices(getActivity());
if(mCursorServices.getCount()>0){
//indicate the fields we want to show (from) and where (to)
String[] from = new String[] { "name", "description"};
int[] to = new int[] { R.id.checkBoxService,0};
ListView lvServices = (ListView) v.findViewById (R.id.listViewServices);
ListServicesCursorAdapter notes = new ListServicesCursorAdapter (getActivity(), R.layout.activity_file_service, mCursorServices, from, to, 0);
lvServices.setAdapter(notes);
为什么我会得到这种行为？我得到了列表中的所有名称，但是当我以水平方式按下按钮（我的意思是水平放置平板电脑）并在列表中获得滚动条时，我没有得到正确的描述。另一方面，如果我垂直使用平板电脑，我不会在我的列表中看到滚动条，我会在每个按钮中获得正确的描述。
这是我的布局：
<ListView
android:id="@+id/listViewServices"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_weight="1" >
</ListView>
解决方案： newView 应如下所示：
@Override
public View newView(Context context, Cursor cursor, ViewGroup parent) {
final LayoutInflater inflater = LayoutInflater.from(context);
View v = inflater.inflate(layout, parent, false);
return v;
}
和 bindView 应该是这样的：
@Override
public View bindView(View v, Context context, Cursor cursor) {
//Column of BD that we want to recover
String column = null;
//Index of the column of DB
int nameCol = 0;
//Result of obtain the index of the column of DB
String nombre = null;
//Name of the textView in the Layout where we want to show the result
TextView name_text= null;
String description = null;
String nameService = null;
//For each value of DB, we show it in the text view.
for (int i=0; i<from.length; i++){
column= from[i];
nameCol = cursor.getColumnIndex(column);
name = cursor.getString(nameCol);
//the values to[i] equals to 0 indicates values that we need but
//that we are not showing in the list directly
//0 -> description
if(to[i] == 0){
description = name;
}else{
nameService = name;
name_text = (TextView) v.findViewById(to[i]);
if (name_text != null) {
name_text.setText(name);
}
}
}
/********************************NEW CODE ************************************/
String uniMedition = cursor.getString(cursor.getColumnIndex("unitMedition"));
if(uniMedition.equals("none")){
EditText etMedida = (EditText) v.findViewById(R.id.editTextMedida);
etMedida.setVisibility(View.INVISIBLE);
TextView tvUniMedition = (TextView) v.findViewById(R.id.textViewUniMedition);
tvUniMedition .setVisibility(View.INVISIBLE);
}else{
EditText etMedida = (EditText) v.findViewById(R.id.editTextMedida);
etMedida.setVisibility(View.VISIBLE);
TextView tvUniMedition = (TextView) v.findViewById(R.id.textViewUniMedition);
tvUniMedition .setVisibility(View.VISIBLE);
tvUniMedition .setText(uniMedition);
}
/********************************END NEW CODE ************************************/
ImageButton buttonDescription = (ImageButton) v.findViewById(R.id.imageButtonDescription);
//we store in a bundle the name and description of the service, so we can use it in
// the setOnClickListener method.
final Bundle mArguments = new Bundle();
mArguments.putString("name", nameService);
mArguments.putString("description", description);
buttonDescription .setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v){
AlertDialog.Builder builder = new AlertDialog.Builder(v.getContext());
builder.setMessage(mArguments.getString("description"))
.setTitle(mArguments.getString("name"))
.setCancelable(false)
.setPositiveButton("Ok", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
dialog.cancel();
}
});
AlertDialog alert = builder.create();
alert.show();
}});
}
}
现在一切正常！