Question

我正在尝试存储用户的步数，但是当我重新启动或关闭移动设备时，数据就会消失。 SharedPreferences未保存数据。重新启动手机后进入应用程序时，它会变为0。怎么解决？

代码如下：

package com.threemusketeers.healthmaster;

import android.app.Activity;
import android.app.Application;
import android.content.Context;
import android.content.SharedPreferences;
import android.hardware.Sensor;
import android.hardware.SensorEvent;
import android.hardware.SensorEventListener;
import android.hardware.SensorManager;
import android.preference.PreferenceManager;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.TextView;

public class Pedometer extends Activity implements SensorEventListener {
private TextView textView;

private SensorManager mSensorManager;

private Sensor mStepCounterSensor;

private Sensor mStepDetectorSensor;

SharedPreferences sharedPreferences;

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_pedometer);
    textView = (TextView) findViewById(R.id.textview);

    mSensorManager = (SensorManager)
            getSystemService(Context.SENSOR_SERVICE);
    mStepCounterSensor = mSensorManager
            .getDefaultSensor(Sensor.TYPE_STEP_COUNTER);
    mStepDetectorSensor = mSensorManager
            .getDefaultSensor(Sensor.TYPE_STEP_DETECTOR);
}

public void onSensorChanged(SensorEvent event) {
    sharedPreferences = PreferenceManager.getDefaultSharedPreferences(getApplicationContext());
    SharedPreferences.Editor editor = sharedPreferences.edit();

    Sensor sensor = event.sensor;
    float[] values = event.values;
    int value = -1;

    if (values.length > 0) {
        value = (int) values[0];
    }
    if (sensor.getType() == Sensor.TYPE_STEP_COUNTER) {
        editor.putInt("steps", value).commit();
        textView.setText("Step Counter Detected : " + sharedPreferences.getInt("steps", 0));
    } else if (sensor.getType() == Sensor.TYPE_STEP_DETECTOR) {
        // For test only. Only allowed value is 1.0 i.e. for step taken
        editor.putInt("steps", value).commit();
        textView.setText("Step Detector Detected : " + sharedPreferences.getInt("steps", 0));
    }
}

   @Override
   public void onAccuracyChanged(Sensor sensor, int accuracy) {

   }

   protected void onResume() {

       super.onResume();

       mSensorManager.registerListener(this, mStepCounterSensor,

            SensorManager.SENSOR_DELAY_FASTEST);
       mSensorManager.registerListener(this, mStepDetectorSensor,

            SensorManager.SENSOR_DELAY_FASTEST);

   }

   protected void onStop() {
       super.onStop();
       mSensorManager.unregisterListener(this, mStepCounterSensor);
       mSensorManager.unregisterListener(this, mStepDetectorSensor);
   }
}

Answer 1

你做了一些奇怪的事情，即将值写入For Each Cell In NewData 'where NewData is the range with all of the headings Range(Cell.Offset(1, 0), Cell.Offset(1, 0).End(xlDown)).Copy Worksheets("Total").Activate Worksheets("Total").Rows(2).Find(Cell.Value).End(xlDown).Offset(1, 0).PasteSpecial Paste:=xlPasteValues, Operation:=xlNone, SkipBlanks:=False, Transpose:=False On Error Resume Next 'error handling skips data columns in sheet 1 that are not found in sheet 2 Next Cell，然后再从那里得到它，这是一个不必要的IO操作。

由于步数计数器

，这也会导致您的问题

上次重启后用户采取的步骤数

（来自documentation）

重启设备时，计数重置为0.您不更新SharedPreferences中的TextView，而是更改步数更改（从0到1）覆盖SharedPreferences中的先前值从那里更新TextView的值。

如果当前步数低于保存值，则需要更改保存逻辑以首先从sharedprefs读取值并将其添加为基值。或者自己计算步进检测器的步数。

Answer 2

尝试使用如下所述的SharedPreferences：

保存数据：

SharedPreferences prefs = getSharedPreferences("my_prefs", MODE_PRIVATE);
Editor editor = prefs.edit();
editor.putString("name", "Ravish");
editor.commit();

要检索数据：

SharedPreferences prefs = getSharedPreferences("my_prefs", MODE_PRIVATE);
String name= prefs.getString("name");

sharedPreferences不保存数据

2 个答案: