Question

我有一个包含listview的活动。 listView有一个自定义适配器，因为它包含两个textViews和一个checkBox。现在我希望每次调用该活动onPause时，我想检查所有复选框状态并将它们保存到ArrayList<String>（好吧我知道如何解析东西）。我知道我可以从getView()保存，但我不知道如何在保存模式下重新加载listView＆＃34;。

代码：

adapter.class：

public class adapter extends ArrayAdapter<String> {
LayoutInflater mInflater;
List<String> text, quantity;
boolean saving = false;
String cbListName;
String[] cbArray;
ArrayList<String> cbList;
Context context;

public adapter(Context context, int resource, int textViewResourceId, List<String> objects, List<String> quantities, String arrayName) {
    super(context, resource, textViewResourceId, objects);
    mInflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    text = objects;
    quantity = quantities;
    cbListName = arrayName + "_cbs";
    this.context = context;
}

public View getView(int position, View convertView, ViewGroup parent){
    View row = mInflater.inflate(R.layout.items_list_element, null);

    CheckBox cb = (CheckBox)row.findViewById(R.id.gotItCheckBox);
    TextView itemName = (TextView)row.findViewById(R.id.text1);
    TextView itemQuantity = (TextView)row.findViewById(R.id.quantityText);

    //Populate text fields
    if (text.size() > 0){
        itemName.setText(text.get(position));
        itemQuantity.setText(quantity.get(position));
    }

    loadArray();

    //Sets checkbox states   
    /*if (cbList.size() > 0 & cbList.get(position).equals("true")){
        cb.setChecked(true); <-- This is in comment because throws exceptions otherwise
    }*/

    //Save checkbox values if saving is true
    if (saving){
        if (cb.isChecked()){
            cbList.add(position, "true");
        }else {
            cbList.add(position, "false");
        }
        saving = false;
    }

    return row;
}

private void loadArray(){
    cbArray = functions.loadArray(cbListName, context);
    cbList = new ArrayList<String>();
    Collections.addAll(cbList, cbArray);
}

public void saveArray(){
    cbArray = new String[cbList.size()];
    cbArray = cbList.toArray(cbArray);
    functions.saveArray(cbArray, cbListName, context);
}

}

使用listView

的

活动

public class ShoppingList extends MenuActivity {
EditText itemNameField, itemQuantityField;
Button addButton, plusButton, minusButton;
ListView listView;
int quantity;
String [] itemArray, itemQuantityArray;
ArrayList<String> itemList, itemQuantityList;
adapter adapter;
String saveArrayName;
Context context = this;

public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.shoppinglist);
    getWindow().setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_STATE_ALWAYS_HIDDEN);

    //Sets up all the views from ids
    setupViews();

    //Defines button click actions
    plusButton.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            quantity = Integer.parseInt(itemQuantityField.getText().toString());
            quantity ++;
            itemQuantityField.setText(String.valueOf(quantity));
        }
    });
    minusButton.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            quantity = Integer.parseInt(itemQuantityField.getText().toString());
            quantity --;
            if (quantity < 1){
                quantity = 1;
            }
            itemQuantityField.setText(String.valueOf(quantity));
        }
    });
    addButton.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            if (!(itemNameField.getText().toString().equals(""))){
                itemList.add(itemNameField.getText().toString());
                itemQuantityList.add(itemQuantityField.getText().toString());
                adapter.notifyDataSetChanged();
                itemNameField.setText("");
                itemQuantityField.setText("1");
                InputMethodManager mgr = (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);
                mgr.hideSoftInputFromWindow(addButton.getWindowToken(), 0);
            }
        }
    });

    //Calls the function to load the array
    setupArray();

    adapter = new com.grizeldi.gShopper.adapter(this, R.layout.items_list_element, android.R.id.text1, itemList, itemQuantityList, saveArrayName);
    listView.setAdapter(adapter);
    listView.setCacheColorHint(0);
}

private void setupViews(){
    itemNameField = (EditText) findViewById(R.id.addItemField);
    itemQuantityField = (EditText) findViewById(R.id.itemQuantityField);
    addButton = (Button) findViewById(R.id.addItemButton);
    plusButton = (Button) findViewById(R.id.plusButton);
    minusButton = (Button) findViewById(R.id.minusButton);
    listView = (ListView) findViewById(R.id.itemView);
}

private void setupArray(){
    Intent whoStartedIt = getIntent();
    saveArrayName = whoStartedIt.getStringExtra("arrayName");

    //Loads item names
    itemArray = functions.loadArray(saveArrayName, this);
    itemList = new ArrayList<String>();
    Collections.addAll(itemList, itemArray);

    //Loads item quantities
    itemQuantityArray = functions.loadArray(saveArrayName + "_quantity", this);
    itemQuantityList = new ArrayList<String>();
    Collections.addAll(itemQuantityList, itemQuantityArray);
}

public void onPause(){
    super.onPause();

    //Saves item names
    itemArray = new String[itemList.size()];
    itemArray = itemList.toArray(itemArray);
    functions.saveArray(itemArray, saveArrayName, this);

    //Saves item quantities
    itemQuantityArray = new String[itemQuantityList.size()];
    itemQuantityArray = itemQuantityList.toArray(itemQuantityArray);
    functions.saveArray(itemQuantityArray, saveArrayName + "_quantity", this);

    /*
    adapter.notifyDataSetChanged(); <-- I want to save array here
    adapter.saveArray();*/
}
}

如果我的问题太混乱，我很抱歉：P

有没有人知道这里发生了什么？我需要尽快回答。

编辑：MenuActivity只是一个扩展活动并在单击菜单按钮时弹出菜单的类。

Answer 1

在我看来，你不应该使用共享偏好。试试这个。保留一个mysqlitedatabase表，可以存储复选框值，即1表示已选中，0表示未选中。单击checkBox时，调用其侦听器并更改数据库中的值。如果您担心处理使用LoaderManager类

Answer 2

好的，我想出了如何解决这个问题。

我使用onCheckedChangeListener来操作数组值。

如何将listview中的复选框状态保存到sharedpreferences

2 个答案: