Question

我正在寻求帮助。在我的一个活动中，我有变量id_wallet，我想将值保存在SharedPreferences中并用于其他活动。怎么做？代码简介。我在其他类中使用变量wallet_id。

public class ChooseWallet extends AppCompatActivity {


public static int wallet_id;

        listViewChooseWallet.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {

            wallet_id= (position+1);
            SaveInt("key",wallet_id);
            Toast.makeText(getApplicationContext(), "Wallet number "+(position+1)+" active!", Toast.LENGTH_SHORT).show();
        }
    });

public void SaveInt(String key, int value){
    sharedPreferences = PreferenceManager.getDefaultSharedPreferences(getApplicationContext());
    SharedPreferences.Editor editor = sharedPreferences.edit();
    editor.putInt(key, value);
    editor.commit();
}
public void LoadInt(Context mContext){
    sharedPreferences = PreferenceManager.getDefaultSharedPreferences(mContext);
    walllet_id  = sharedPreferences.getInt("key", 1);
}

其他活动（简称）：

public class AddOut extends AppCompatActivity {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_add_out);
    addoutbalnce.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            if (Double.parseDouble(amount.getText().toString()) > 0 && ChooseWallet.wallet_id != 0 && amount.getText().toString() != null) {
                double amount = Double.parseDouble(amount.getText().toString());
                amount= (-amount);
                String coment = commentout.getText().toString();
                ChooseWallet wb = new ChooseWallet();
                wb.LoadInt(getApplicationContext());


                db.UpdateAmount(ChooseWallet.wallet_id,amount);
                db.AddTransaction(ChooseWallet.wallet_id, amount, coment, id_cat, date);

                Toast.makeText(getApplicationContext(), "Add", Toast.LENGTH_SHORT).show();
            }
            else if(Double.parseDouble(amount.getText().toString()) < 0 || amount.getText().toString() == null){
                amount.setError("Error!");
            }
        }
    });

Answer 1

可能您的模拟器不保存共享偏好。尝试使用手机启动应用。

Android SharedPreferences，无效。变量值仍然= 0

1 个答案: