未使用共享首选项保存数据

Question

我正在创建一个番茄计时器应用程序。 它有2个活动：

• 主要活动是设置时间。
• 最近的活动包含最近设置的时间。

我创建了一个Shared Preferences object 来保存设置的时间，我希望这些时间显示在“最近活动”的按钮中。 但是，似乎没有保存数据，而是显示 package 名称。

主要活动

package com.example.pomotimer;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Context;
import android.content.Intent;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.os.CountDownTimer;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.TimePicker;
import android.widget.Toast;

import java.util.Locale;

public class Activity2 extends AppCompatActivity {


    public static final String EXTRA_TEXT = "com.example.pomotimer.EXTRA_TEXT";
    private TextView TextViewCountdown;
    private Button Button_Start_Pause;
    private Button Reset;
    SharedPreferences sp;
    private Button buttonSet;
    private Button select_Time;
    private EditText edit_Text_Input;


    private CountDownTimer countDownTimer;
    public long mStartTimeinMillis;
    private long timeLeft = mStartTimeinMillis;

    private boolean timerRunning;



    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_2);

        TextViewCountdown = findViewById(R.id.textViewCount);
        Button_Start_Pause = findViewById(R.id.bnStartPause);
        Reset = findViewById(R.id.reset);
        select_Time = findViewById(R.id.selectTime);
        edit_Text_Input = findViewById(R.id.edit_Text_Input);
        buttonSet = findViewById(R.id.buttonSet);

        sp = getSharedPreferences("MyPrefs", Context.MODE_PRIVATE);






        select_Time.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                edit_Text_Input.setVisibility(View.VISIBLE);
                buttonSet.setVisibility(View.VISIBLE);

                buttonSet.setOnClickListener(new View.OnClickListener() {
                    @Override
                    public void onClick(View v) {
                        String input = edit_Text_Input.getText().toString();
                        if (input.length() == 0){
                            Toast.makeText(Activity2.this, "Field can't be empty", Toast.LENGTH_SHORT).show();
                            return;
                        }
                        long millisInput = Long.parseLong(input)*60000;
                        if (millisInput == 0){
                            Toast.makeText(Activity2.this, "Timer cannot be set to 0", Toast.LENGTH_SHORT).show();
                            return;
                        }

                        setTime(millisInput);
                        edit_Text_Input.setText("");



                    }


                });


            }




        });




        Button_Start_Pause.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                if (timerRunning){
                    pauseTimer();
                }

                else{
                    startTimer();
                }
            }
        });

        Reset.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                resetTimer();
            }
        });
        int minutes = (int) (timeLeft/1000)/60;
        int seconds = (int) (timeLeft/1000)%60;

        String timeLeftFormatted = String.format(Locale.getDefault(),"%02d:%02d", minutes, seconds);
        TextViewCountdown.setText(timeLeftFormatted);





    }

    @Override
    public void finish() {
        super.finish();
        overridePendingTransition(R.anim.slide_in_left, R.anim.slide_out_right);
    }

    public void setTime(long milliseconds){
         mStartTimeinMillis = milliseconds;
         resetTimer();
         SP();
    }

    private void startTimer(){
        countDownTimer = new CountDownTimer(timeLeft,1000) {
            @Override
            public void onTick(long millisUntilFinished) {
                // The countdown timer has an automatic method of reducing time by 1s
                    timeLeft = millisUntilFinished;

                    int minutes = (int) (timeLeft/1000)/60;
                    int seconds = (int) (timeLeft/1000)%60;

                    String timeLeftFormatted = String.format(Locale.getDefault(),"%02d:%02d", minutes, seconds);
                    TextViewCountdown.setText(timeLeftFormatted);

            }





            @Override
            public void onFinish() {
                timerRunning = false;
                Button_Start_Pause.setText("Start");
                Button_Start_Pause.setVisibility(View.INVISIBLE);

            }
        }.start();

        timerRunning = true;
        Button_Start_Pause.setText("pause");

    }

    int data = (int) timeLeft;


    private void pauseTimer(){
        countDownTimer.cancel();
        timerRunning = false;
        Button_Start_Pause.setText("Start");

    }

    private void resetTimer(){
            timeLeft = mStartTimeinMillis;
        int minutes = (int) (timeLeft/1000)/60;
        int seconds = (int) (timeLeft/1000)%60;
        Button_Start_Pause.setVisibility(View.VISIBLE);

        String timeLeftFormatted = String.format(Locale.getDefault(),"%02d:%02d", minutes, seconds);
        TextViewCountdown.setText(timeLeftFormatted);
    }

    @Override
    protected void onStop() {
        super.onStop();

        SharedPreferences prefs = getSharedPreferences("prefs", MODE_PRIVATE);
        SharedPreferences.Editor editor = prefs.edit();
        editor.putLong("millisleft", timeLeft);
        editor.putBoolean("timerRunning", timerRunning);

        editor.apply();

    }

    @Override
    protected void onStart() {
        super.onStart();

        SharedPreferences prefs = getSharedPreferences("prefs", MODE_PRIVATE);
        timeLeft = prefs.getLong("millisleft",mStartTimeinMillis);
        timerRunning = prefs.getBoolean("timeRunning", false);

        int minutes = (int) (timeLeft/1000)/60;
        int seconds = (int) (timeLeft/1000)%60;

        String timeLeftFormatted = String.format(Locale.getDefault(),"%02d:%02d", minutes, seconds);
        TextViewCountdown.setText(timeLeftFormatted);

    }
    public void SP() {
        String data = TextViewCountdown.toString();
        SharedPreferences.Editor editor = sp.edit();
        editor.putString("time", data);
        editor.commit();
        Toast.makeText(Activity2.this, "this ", Toast.LENGTH_SHORT).show();

    }
}

最近的活动

package com.example.pomotimer;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Context;
import android.content.Intent;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.widget.Button;
import android.widget.TextView;

public class recentActivity extends AppCompatActivity {

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

        Button button = findViewById(R.id.button_data);



//        String number = getIntent().getStringExtra("keydata");

//        button.setText(number);

        SharedPreferences sp = getApplicationContext().getSharedPreferences("MyPrefs", Context.MODE_PRIVATE);
        String time = sp.getString("time", "");

        button.setText(time);


    }
}

Answer 1

而不是String data = TextViewCountdown.toString(); 它应该是String data = TextViewCountdown.getText().toString();