Question

我在活动中有简单的微调器。如果我使用sharedPreferences选择列表中的内容，我想保存微调器的位置。但是，当我换到另一个活动并再次回来时，它会重置为默认状态。我不知道为什么，我的偏好没有保存，或者我的偏好没有加载。

这是我的活动

    package com.bani.latihan;

import android.content.Context;
import android.content.Intent;
import android.content.SharedPreferences;
import android.content.res.Configuration;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.view.WindowManager;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.Spinner;
import android.widget.Toast;

/**
 * Created by Bani Burhanuddin on 25/02/2016.
 */
public class Intent6 extends AppCompatActivity {



@Override
public void onConfigurationChanged(Configuration newConfig) {
    super.onConfigurationChanged(newConfig);
}

@Override
protected void onCreate(Bundle savedInstanceState) {
    this.getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
            WindowManager.LayoutParams.FLAG_FULLSCREEN);
    super.onCreate(savedInstanceState);
    getSupportActionBar().setDisplayShowHomeEnabled(true);
    getSupportActionBar().setLogo(R.mipmap.ic_launcher);
    getSupportActionBar().setDisplayUseLogoEnabled(true);
    setContentView(R.layout.halaman_6);

    Button btnback = (Button) findViewById(R.id.buttonPrev6);
    Button btnHome = (Button) findViewById(R.id.buttonHome6);

    btnHome.setOnClickListener(new View.OnClickListener() {
        public void onClick(View v) {
            // TODO Auto-generated method stub
            startActivity(new Intent(Intent6.this, Main.class));
            finish();

        }
    });

    btnback.setOnClickListener(new View.OnClickListener() {
        public void onClick(View v) {
            // TODO Auto-generated method stub
            startActivity(new Intent(Intent6.this, Intent5.class));
            finish();

        }
    });




    final Spinner spinner6 = (Spinner) findViewById(R.id.spinner6);
    ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource(
            this, R.array.android_layout_arrays, android.R.layout.simple_spinner_item);
    adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);

    spinner6.setAdapter(adapter);
   final String firstItem = String.valueOf(spinner6.getSelectedItem());



    spinner6.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
        @Override
        public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
            if (firstItem.equals(String.valueOf(spinner6.getSelectedItem()))) {

            } else {
                Toast.makeText(parent.getContext(),
                        "Ko Milih : " + parent.getItemAtPosition(position).toString(),
                        Toast.LENGTH_LONG).show();

            }
        }

        @Override
        public void onNothingSelected(AdapterView<?> parent) {
        }
    });

    SharedPreferences test = getSharedPreferences("Preferences6_1", Context.MODE_PRIVATE);
    int spinnerValue = test.getInt("Preferences6_1",-1);
    if(spinnerValue != -1)
        // set the value of the spinner
        spinner6.setSelection(spinnerValue);


}

@Override
public void onPause() {
    super.onPause();
    Spinner spinner6 = (Spinner) findViewById(R.id.spinner6);
    SharedPreferences.Editor prefEditor = getSharedPreferences("Preferences6", 0).edit();
    prefEditor.putInt("spinner6", spinner6.getSelectedItemPosition());
    prefEditor.apply();
}






}

Answer 1

您在阅读和写作时使用不同的共享偏好名称。你用来阅读的关键也是错误的。

请更改以下代码

SharedPreferences test = getSharedPreferences("Preferences6_1", Context.MODE_PRIVATE);
int spinnerValue = test.getInt("Preferences6_1",-1);

到

SharedPreferences test = getSharedPreferences("Preferences6", Context.MODE_PRIVATE);
int spinnerValue = test.getInt("spinner6",-1);

如何使用SharedPreferences保存和检索微调器状态

1 个答案: