我有一个listview,每行包含一个带有复选框的textview,所以当选中复选框并向下滚动listview时,复选框实例将从一个地方转到另一个地方(重复使用..)我有几个选中复选框如何修复我试图将复选框绑定到列表视图,但这不起作用我的代码是:
SimpleCursorAdapter adapter =new SimpleCursorAdapter(this,R.layout.rating,cu,new String[]{"Title","Favorites"}, new int[]{R.id.text1,R.id.bt_rating},CursorAdapter.FLAG_REGISTER_CONTENT_OBSERVER);
listv.setAdapter(adapter);
adapter.setViewBinder(new SimpleCursorAdapter.ViewBinder(){
/** Binds the Cursor column defined by the specified index to the specified view */
public boolean setViewValue(View view, Cursor cursor, int columnIndex){
if(view.getId() == R.id.bt_rating){
((CheckBox)view).setChecked(Boolean.valueOf(cursor.getString(cursor.getColumnIndex("Favorites"))));
((CheckBox)view).setOnCheckedChangeListener(myCheckChangList);
return true; //true because the data was bound to the view
}
return false;
}
});
OnCheckedChangeListener myCheckChangList = new OnCheckedChangeListener() {
public void onCheckedChanged(CompoundButton buttonView,
boolean isChecked) {
buttonView.setChecked(isChecked);
}
};
我的listview行内容的xml代码是:
<?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"
android:orientation="horizontal" >
<CheckBox
android:id="@+id/bt_rating"
android:focusable="false"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_vertical"
android:button="@android:drawable/btn_star"/>
<TextView
android:id="@+id/text1"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:textSize="@dimen/fsinlistview"
/>
</LinearLayout>
答案 0 :(得分:0)
在任何Listview中,视图都会被重用。当您滚动列表时,那些向上和向下滚动的页面将被回收并与下面的新信息一起使用。
您需要使用稀疏数组跟踪复选框。当用户触摸每个索引时,将数组中的索引标记为cherked / unchecked。然后,您可以根据数组中的值设置复选框的状态。
以下是旧应用程序的一些示例代码,它既可以执行“全选”复选框,也可以管理已选中和未选中的整个列表。这是我写的课堂考勤应用程序,所以教师选择“全部”在课堂上然后取消选择那些不在场的应用程序要容易得多。
我在这个listview中有两个复选框,还有两个稀疏数组,itemCheckedHere和itemCheckedLate(无论学生是在课堂上还是迟到)。
public class MyDataAdapter extends SimpleCursorAdapter {
private Cursor c;
private Context context;
private Long classnum;
private gradeBookDbAdapter mDbHelper;
public static final int LATE=2;
public static final int ATTEND=1;
int idxCol;
int idx;
// itemChecked will store the position of the checked items.
public MyDataAdapter(Context context, int layout, Cursor c, String[] from,
int[] to, Long mRowId) {
super(context, layout, c, from, to);
this.c = c;
this.context = context;
mDbHelper = new gradeBookDbAdapter(context);
mDbHelper.open();
classnum = mRowId;
c.moveToFirst();
}
public class ViewHolder{
public TextView text;
public TextView text2;
public ImageView image;
public CheckBox here;
public CheckBox late;
}
public View getView(final int pos, View inView, ViewGroup parent) {
Bitmap bm;
ImageView studentPhoto;
View vi=inView;
final ViewHolder holder;
if (inView == null) {
LayoutInflater inflater = (LayoutInflater) context
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
vi = inflater.inflate(R.layout.show_attendance, null);
holder=new ViewHolder();
holder.text=(TextView)vi.findViewById(R.id.stuname);
holder.text2=(TextView)vi.findViewById(R.id.stuIndex);
holder.image=(ImageView)vi.findViewById(R.id.icon);
holder.here=(CheckBox)vi.findViewById(R.id.attend);
holder.late=(CheckBox)vi.findViewById(R.id.late);
vi.setTag(holder);
}
else
holder=(ViewHolder)vi.getTag();
c.moveToPosition(pos);
int index = c.getColumnIndex(gradeBookDbAdapter.KEY_NAME);
String name = c.getString(index);
holder.text.setText(name);
index = c.getColumnIndex(gradeBookDbAdapter.KEY_ROWID);
String Index = c.getString(index);
holder.text2.setText(Index);
bm = gradeBookDbAdapter.getStudentPhoto(name);
if (bm != null) {
holder.image.setImageBitmap(bm);
}
else {
// use icon image
holder.image.setImageResource(R.drawable.person_icon);
}
// pull out existing attend/late fields and set accordingly
int attend = c.getInt(c.getColumnIndex(gradeBookDbAdapter.KEY_ATTEND));
if(attend==1){
holder.here.setChecked(true);
itemCheckedHere.set(pos, true);
}
//else {
// holder.here.setChecked(false);
// itemCheckedHere.set(pos, false);
//}
int late = c.getInt(c.getColumnIndex(gradeBookDbAdapter.KEY_LATE));
if (late==1){
holder.late.setChecked(true);
itemCheckedLate.set(pos, true);
}
//else {
// holder.late.setChecked(false);
// itemCheckedLate.set(pos, false);
//}
if (selectAllTouched) {
if(selectAll){
holder.here.setChecked(true);
itemCheckedHere.set(pos, true);
int who= new Integer(holder.text2.getText().toString());
mDbHelper.updateAttend(who, classnum, ATTEND, 1, attendDate );
}
else{
holder.here.setChecked(false);
itemCheckedHere.set(pos, false);
int who = new Integer(holder.text2.getText().toString());
mDbHelper.updateAttend(who, classnum, ATTEND, 0, attendDate );
}
}
holder.here.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
CheckBox cb = (CheckBox) v.findViewById(R.id.attend);
if (cb.isChecked()) {
itemCheckedHere.set(pos, true);
int Index = new Integer(holder.text2.getText().toString());
mDbHelper.updateAttend(Index, classnum, ATTEND, 1, attendDate );
} else if (!cb.isChecked()) {
itemCheckedHere.set(pos, false);
int Index = new Integer(holder.text2.getText().toString());
mDbHelper.updateAttend(Index, classnum, ATTEND, 0, attendDate );
}
}
});
holder.late.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
CheckBox cb = (CheckBox) v.findViewById(R.id.late);
if (cb.isChecked()) {
itemCheckedLate.set(pos, true);
int Index = new Integer(holder.text2.getText().toString());
mDbHelper.updateAttend(Index, classnum, LATE, 1, attendDate );
} else if (!cb.isChecked()) {
itemCheckedLate.set(pos, false);
int Index = new Integer(holder.text2.getText().toString());
mDbHelper.updateAttend(Index, classnum, LATE, 0, attendDate );
}
}
});
holder.here.setChecked(itemCheckedHere.get(pos)); // this will Check or Uncheck the
holder.late.setChecked(itemCheckedLate.get(pos)); // this will Check or Uncheck the
// CheckBox in ListView
// according to their original
// position and CheckBox never
// loss his State when you
// Scroll the List Items.
return vi;
}
}
}
答案 1 :(得分:0)
看起来你的OnCheckedChangedListener
就是问题所在。如果您查看代码,请参阅每个复选框,以获取对相同侦听器的引用。因此,当您选中一个复选框时,您也会将所有其他复选框设置为已选中 - 并且您也不会更新您的支持数据。
您的OnCheckedChangedListener
不应该更新复选框的视图状态 - 由于状态已经更改,因此会触发回调。
因此,当用户选中复选框时,您需要执行以下步骤:
您可以执行以下操作,使用其代表的行的ID标记视图:
public boolean setViewValue(View view, Cursor cursor, int columnIndex){
if(view.getId() == R.id.bt_rating){
view.setTag(cursor.getInt(cursor.getColumnIndex(SomeDBContract.ID)));
((CheckBox)view).setChecked(Boolean.valueOf(cursor.getString(cursor.getColumnIndex("Favorites"))));
((CheckBox)view).setOnCheckedChangeListener(myCheckChangList);
return true; //true because the data was bound to the view
}
return false;
}
然后,在您的监听器中,您可以根据该ID更新您的数据库:
CheckedChangeListener myCheckChangList = new OnCheckedChangeListener() {
public void onCheckedChanged(CompoundButton buttonView,
boolean isChecked) {
int rowId = (int) buttonView.getTag();
// Handle updating the database as per normal
updateSomeDbRowAsChecked(rowId, isChecked);
}
};
最后,在更新数据库行后,您需要使用新游标更新游标适配器:
myAdapter.swapCursor(newCursor);
您必须调整所有这些以适合您的代码,但它应该让您了解解决此问题的一种方法。