问题
- I'm having a problem with saving data permanently. It should be simple, I'm sending data to another Fragment and it works perfectly, however, I have no idea how to save data.
I tried something, but I was wondering if you could help me out.
In my code, I'm sending a data to another Fragment by pushing a Button.
So this is the code:
package com.example.mskydraw.notetech;
import android.content.Context; import android.content.SharedPreferences; import android.os.Bundle; import android.support.v4.app.Fragment; import android.support.v4.app.FragmentManager; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.widget.Button; import android.widget.EditText; import android.widget.Gallery; import android.widget.TextView; import android.widget.Toast; import java.io.FileOutputStream; import static android.content.Context.MODE_PRIVATE;
/** * A simple {@link Fragment} subclass. */ public class Cofo extends Fragment {
final static String SHARED_NAME_STRING="sharedp";
final static String USER_NAME_STRING="user";
public Cofo() {
// Required empty public constructor
}
EditText newTxt;
Button newBtn;
SharedPreferences sharedPreferences;
Context c = getActivity();
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
View view = inflater.inflate(R.layout.fragment_cofo, container, false);
// finding my bouton and text on layout
newTxt = (EditText)view.findViewById(R.id.Txt);
newBtn = (Button)view.findViewById(R.id.Btn);
sharedPreferences=this.c.getSharedPreferences(SHARED_NAME_STRING,Context.MODE_PRIVATE);
String userNameString=sharedPreferences.getString(USER_NAME_STRING, "");
newTxt.setText(userNameString);
// whenever I click on the bouton
newBtn.setOnClickListener(new View.OnClickListener(){
@Override
public void onClick(View v){
//This code allows you to jump into another fragment
// Call the fragment to where I want to jump
Main_content newmain = new Main_content();
//Here we are going to learn to how to save data
String Message = newTxt.getText().toString();
String file_name = "Hello_file";
// Create an object output string
//here we are sending data to another fragment
//You have declare bundle
Bundle bundle = new Bundle();
// You can use bundle.putxx everything such as String...float..
bundle.putInt("N1",5);
//calling the fragment I'm going to send the data
// and I'm going to send data I saved on bundle.
newmain.setArguments(bundle);
// The process of declaration fragment
FragmentManager manager = getFragmentManager();
// Jumping into main content fragment
manager.beginTransaction().replace(R.id.fragment,newmain).commit();
if (newTxt.getText().toString().equals("Hello")){
Toast.makeText(Cofo.this.getActivity(), "true", Toast.LENGTH_SHORT).show();
}
else{
Toast.makeText(Cofo.this.getActivity(), "Hi", Toast.LENGTH_SHORT).show();
}
SharedPreferences.Editor editor=sharedPreferences.edit();
}
});
return view;
}
}
回答1:
If you want to use Shared Preferences instead of sending the data through bundles, use this code:
String stringToSave = "Save me!";
// To save data to SP
SharedPreferences.Editor editor = getContext().getSharedPreferences(SHARED_NAME_STRING, MODE_PRIVATE).edit();
editor.putString(USER_NAME_STRING, stringToSave);
editor.apply();
// To load the data at a later time
SharedPreferences prefs = getContext().getSharedPreferences(SHARED_NAME_STRING, MODE_PRIVATE);
String loadedString = prefs.getString(USER_NAME_STRING, null);
This code is setup to work with fragments. If you use an Activity instead, remove getContext() in front of getSharedPreferences().
来源:https://stackoverflow.com/questions/46051658/how-to-save-data-by-using-sharedpreferences-in-a-fragment