【发布时间】：2018-04-27 18:02:26
【问题描述】：
我的最终目标是在 SQLite 表中为 ListView 的每个项目存储一个自定义对象“Place”的实例。
第 1 步将简单地提取 Place 对象，我能够使用适配器获取 Place 的各种成员变量，但我已经尝试了几天来获取列表视图中每个复选框的选中状态，但无法获取它工作，应该没那么难。我已经尝试了所有我能想到的听众，但是当我选中一个框时它没有注册。最后，我确实需要将检查状态作为整数（1 或 0）而不是布尔值，以便将其保存到数据库中。下面我发布了我一直在开发的测试应用程序版本的代码，所以我不再搞砸真实的东西，我真的很感激任何帮助！
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/linearlayout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="horizontal">
<CheckBox
android:id="@+id/checkbox"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_vertical"
android:gravity="center_vertical"
android:onClick="itemClicked"
android:paddingRight="8dp"/>
<TextView
android:id="@+id/place_nameandaddress"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_vertical"
android:gravity="center_vertical"
android:minHeight="?android:listPreferredItemHeight"/>
</LinearLayout>
public class Place {
String mName;
String mAddress;
double mLatitude;
double mLongitude;
public int mCheckedStatus;
public Place(String name, String address, double latitude, double longitude, int integer){
mName = name;
mAddress = address;
mLatitude = latitude;
mLongitude = longitude;
mCheckedStatus = integer;
}
public String getName() {
return mName;
}
public String getAddress() {
return mAddress;
}
public double getLatitude() {
return mLatitude;
}
public double getLongitude() {
return mLongitude;
}
public int getCheckedStatus(){ return mCheckedStatus;}
public void setCheckedStatus(int integer){
mCheckedStatus = integer;
}
public boolean isSelected() {
if (mCheckedStatus ==1) {
return true;
} else {
return false;
}
}
}
public class PlaceAdapter extends ArrayAdapter<Place> {
public PlaceAdapter(@NonNull Context context, int resource, ArrayList<Place> places) {
super(context, 0, places);
}
@NonNull
@Override
public View getView(int position, @Nullable View convertView, @NonNull ViewGroup parent) {
if (convertView == null) {
convertView = LayoutInflater.from(getContext()).inflate(R.layout.place_item, parent, false);
}
Place currentPlace = getItem(position);
TextView placeview = convertView.findViewById(R.id.place_nameandaddress);
// remove commas so can later use commas to separate items of the arraylist
String name = currentPlace.getName().replace(",", "");
String address = currentPlace.getAddress().replace(",", "");
placeview.setText(name + " at " + address);
double latitude = currentPlace.getLatitude();
double longitude = currentPlace.getLongitude();
Log.i("Debugging: Lat and Long", String.valueOf(longitude) + String.valueOf(latitude));
CheckBox checkbox = convertView.findViewById(R.id.checkbox);
if (currentPlace.isSelected()) {
checkbox.setChecked(true);
} else {
checkbox.setChecked(false);
}
return convertView;
}
}
public class MainActivity extends AppCompatActivity {
ListView listView;
Uri mIntentUri;
CheckBox checkBox;
int checkboxstatus;
Place currentplace;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ArrayList<Place> places = new ArrayList<Place>();
places.add(new Place("name1", "address1", 12.3, 23.3, 0));
places.add(new Place("name2", "address2", 12.4, 23.4, 0));
places.add(new Place("name3", "address3", 12.5, 23.5, 0));
places.add(new Place("name4", "address4", 12.6, 23.6, 0));
places.add(new Place("name5", "address5", 12.7, 23.7, 0));
listView = findViewById(R.id.listview);
PlaceAdapter placeAdapter = new PlaceAdapter(this, 0, places);
listView.setAdapter(placeAdapter);
}
//get user input from editor and saves value entered into new or edited goal into database
public void saveGoal() {
PlaceAdapter allplacesAdapter = (PlaceAdapter) listView.getAdapter();
ArrayList<String> places = new ArrayList<>();
double latitude = 0;
double longitude = 0;
for ( int i=0; i < allplacesAdapter.getCount();i++) {
currentplace = allplacesAdapter.getItem(i);
String name = currentplace.getName().replace(",","");
String address = currentplace.getAddress().replace(",","");
View view = LayoutInflater.from(this).inflate(R.layout.place_item, listView, false);
checkBox = view.findViewById(R.id.checkbox);
if (checkBox.isChecked()){
currentplace.setCheckedStatus(1);
}
else {
currentplace.setCheckedStatus(0);
}
checkboxstatus = currentplace.getCheckedStatus();
latitude = currentplace.getLatitude();
longitude = currentplace.getLongitude();
String placeString = name + "," + address + "," + latitude + "," + longitude + "," + checkboxstatus;
Log.i("Debugging: placeString",placeString);
places.add(placeString);
}
String arrayString = android.text.TextUtils.join(";", places);
Log.i("Debugging: arrayString",arrayString);
if (TextUtils.isEmpty(arrayString)) {
return;
}
ContentValues contentValues = new ContentValues();
contentValues.put(GoalContract.GoalEntry.COLUMN_PLACE, arrayString);
Log.i("Debugging:contentValues", contentValues.toString());
// informs user of whether values entered into the GoalEditor were saved or there was an error
//if (mIntentUri == null) {
Uri newUri = getContentResolver().insert(GoalContract.GoalEntry.FINAL_CONTENT_URI, contentValues);
if (newUri == null) {
Toast.makeText(this, "Error with saving goal", Toast.LENGTH_LONG).show();
} else {
Toast.makeText(this, "Goal successfully saved", Toast.LENGTH_LONG).show();
}
}
// sets options menu if GoalEditor screen
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.menu_goaleditor, menu);
return true;
}
// determines what should happen if the different menu options in the GoalEditor screen are selected
@Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case R.id.action_save:
saveGoal();
finish();
return true;
}
return super.onOptionsItemSelected(item);
}
}
【问题讨论】：