即使在退出应用程序后,我如何保留从微调器中选择的项目?
how do i preserve item selected from spinner even after exiting app?
下面是我的代码,它在点击时从微调器中获取项目
public class SpinnerActivity extends AppCompatActivity implements AdapterView.OnItemSelectedListener {
private Spinner spinner1,spinner2,spinner3;
private static final String[] sports = {
"Hockey","Cricket","Football","Basketball","Badminton","Tennis"
};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_spinner);
spinner1 = (Spinner)findViewById(R.id.drop_down);
spinner2 = (Spinner)findViewById(R.id.drop_down2);
spinner3 = (Spinner)findViewById(R.id.drop_down3);
ArrayAdapter<String> adapter;
adapter = new ArrayAdapter<String>(this,
android.R.layout.simple_spinner_item,sports);
adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
spinner1.setAdapter(adapter);
spinner2.setAdapter(adapter);
spinner3.setAdapter(adapter);
}
@Override
public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
String item = parent.getItemAtPosition(position).toString();
}
@Override
public void onNothingSelected(AdapterView<?> parent) {
}
}
如何在退出应用程序后保留所选微调器的项目?
您可以使用SharedPreference
来存储选择的值position/id/string。
获取字符串项时添加此行即可
Editor edit = context.getSharedPreferences("Name_of_sf",Context.MODE_PRIVATE).edit();
edit.putString("selected_item", item);
edit.commit();
并且可以简单地检索值作为
context.getSharedPreferences("Name_of_sf",Context.MODE_PRIVATE).getString("selected_item", "");
更多信息@AnirudhSohil 可以看官方文档,里面有很详细的例子,希望对你有帮助。
http://developer.android.com/training/basics/data-storage/shared-preferences.html
下面是我的代码,它在点击时从微调器中获取项目
public class SpinnerActivity extends AppCompatActivity implements AdapterView.OnItemSelectedListener {
private Spinner spinner1,spinner2,spinner3;
private static final String[] sports = {
"Hockey","Cricket","Football","Basketball","Badminton","Tennis"
};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_spinner);
spinner1 = (Spinner)findViewById(R.id.drop_down);
spinner2 = (Spinner)findViewById(R.id.drop_down2);
spinner3 = (Spinner)findViewById(R.id.drop_down3);
ArrayAdapter<String> adapter;
adapter = new ArrayAdapter<String>(this,
android.R.layout.simple_spinner_item,sports);
adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
spinner1.setAdapter(adapter);
spinner2.setAdapter(adapter);
spinner3.setAdapter(adapter);
}
@Override
public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
String item = parent.getItemAtPosition(position).toString();
}
@Override
public void onNothingSelected(AdapterView<?> parent) {
}
}
如何在退出应用程序后保留所选微调器的项目?
您可以使用SharedPreference
来存储选择的值position/id/string。
获取字符串项时添加此行即可
Editor edit = context.getSharedPreferences("Name_of_sf",Context.MODE_PRIVATE).edit();
edit.putString("selected_item", item);
edit.commit();
并且可以简单地检索值作为
context.getSharedPreferences("Name_of_sf",Context.MODE_PRIVATE).getString("selected_item", "");
更多信息@AnirudhSohil 可以看官方文档,里面有很详细的例子,希望对你有帮助。