on button click deletes existing data from TextView after re-launching

问题

Whenever i relaunch my app, getting old values into TextView if some stored by me, but facing a small issue, now after relaunching my app once i do tap on button, it deletes earlier stored data from TextView and shows new one.

I am using SharedPreferences in my program to store textview data, which works just fine for me.

May i know where i am doing mistake ?

see my code below:

public class MainActivity extends ActionBarActivity {

    TextView textViewResult;
    EditText editTextInput;
    String strInput = "";
    Button btnInput;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        final SharedPreferences prefs = PreferenceManager
                .getDefaultSharedPreferences(this);

        textViewResult = (TextView) findViewById(R.id.textResult);
        editTextInput = (EditText) findViewById(R.id.editInput);

        textViewResult.setText(prefs.getString("autoSave", ""));

        textViewResult.addTextChangedListener(new TextWatcher() {

            @Override
            public void onTextChanged(CharSequence arg0, int arg1, int arg2, int arg3) {
                // TODO Auto-generated method stub

            }

            @Override
            public void beforeTextChanged(CharSequence arg0, int arg1, int arg2,
                    int arg3) {
                // TODO Auto-generated method stub

            }

            @Override
            public void afterTextChanged(Editable s) {
                // TODO Auto-generated method stub
                prefs.edit().putString("autoSave", s.toString()).commit();
            }
        });

        btnInput = (Button) findViewById(R.id.button1);
        btnInput.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View arg0) {
                    // TODO Auto-generated method stub
                    String check = editTextInput.getText().toString();
                    if(check.equalsIgnoreCase("ABC"))
                    {
                            strInput = strInput+","+check;

                            Toast.makeText(getApplicationContext(), "done", Toast.LENGTH_LONG).show();
                            textViewResult.setText(strInput);
                            editTextInput.setText("");
                    }
                    else {
                            Toast.makeText(getApplicationContext(), "error", Toast.LENGTH_LONG).show();                    
                    }
            }
        });
    }
}

回答1:

Try this..

btnInput.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View arg0) {
                // TODO Auto-generated method stub
                String check = editTextInput.getText().toString();
                if(check.equalsIgnoreCase("ABC"))
                {
                        strInput = textViewResult.getText().toString()+","+check; 

                        Toast.makeText(getApplicationContext(), "done", Toast.LENGTH_LONG).show();
                        textViewResult.setText(strInput);
                        editTextInput.setText("");
                }
                else {
                        Toast.makeText(getApplicationContext(), "error", Toast.LENGTH_LONG).show();                    
                }
        }
    });

EDIT

Use split("")

String[] total_abc = textViewResult.getText().toString().split(",");
int total = total_abc.length;

回答2:

put prefs.edit().putString("autoSave", s.toString()).commit(); on the OnClick event

and remove textViewResult.setText(prefs.getString("autoSave", "")); instead of it write textViewResult.setText(prefs.getString("autoSave")); you just specify the key value when getting from sharedpreferences thats why you get blank

来源：https://stackoverflow.com/questions/24096173/on-button-click-deletes-existing-data-from-textview-after-re-launching

标签

android

sharedpreferences