基本上，我正在尝试将传感器数据写入.txt我的 SD 卡中的文件中。
.txt当我设置为 (int i = 0; i % 2 == 0; i++) 时，它工作得非常好，即每 2 个样本将数据写入文件。
但正如这段代码所示，我将 5 更改为 1，即我希望将每个样本都写入文件中。一旦我运行它，用户界面就会冻结。
任何人都可以帮我解决这个问题吗？
可以通过创建另一个线程来解决吗？（这样说准确吗？）
我是新手，因此只能大致知道问题可能是由于线程问题。
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import android.app.Activity;
import android.hardware.Sensor;
import android.hardware.SensorEvent;
import android.hardware.SensorEventListener;
import android.hardware.SensorManager;
import android.os.Bundle;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
public class MainActivity extends Activity implements SensorEventListener {
EditText txtData;
Button startButton;
Button stopButton;
File myFile;
FileOutputStream fOut;
OutputStreamWriter myOutWriter;
BufferedWriter myBufferedWriter;
PrintWriter myPrintWriter;
private SensorManager sensorManager;
private long currentTime;
private long startTime;
float[] acceleration = new float[3];
float[] rotationRate = new float[3];
float[] magneticField = new float[3];
boolean stopFlag = false;
boolean startFlag = false;
boolean isFirstSet = true;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// file name to be entered
txtData = (EditText) findViewById(R.id.editText2);
txtData.setHint("Enter File Name here...");
// start button
startButton = (Button) findViewById(R.id.button1);
startButton.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
// start recording the sensor data
try {
myFile = new File("/sdcard/ResearchData/" + txtData.getText() + ".txt");
myFile.createNewFile();
fOut = new FileOutputStream(myFile);
myOutWriter = new OutputStreamWriter(fOut);
myBufferedWriter = new BufferedWriter(myOutWriter);
myPrintWriter = new PrintWriter(myBufferedWriter);
Toast.makeText(getBaseContext(), "Start recording the data set", Toast.LENGTH_SHORT).show();
} catch (Exception e) {
Toast.makeText(getBaseContext(), e.getMessage(), Toast.LENGTH_SHORT).show();
} finally {
startFlag = true;
}
}
});
// stop button
stopButton = (Button) findViewById(R.id.button2);
stopButton.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
// stop recording the sensor data
try {
stopFlag = true;
Toast.makeText(getBaseContext(), "Done recording the data set", Toast.LENGTH_SHORT).show();
} catch (Exception e) {
Toast.makeText(getBaseContext(), e.getMessage(), Toast.LENGTH_SHORT).show();
}
}
});
sensorManager = (SensorManager) getSystemService(SENSOR_SERVICE);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
@Override
public void onSensorChanged(SensorEvent event) {
if (startFlag) {
if (event.sensor.getType() == Sensor.TYPE_ACCELEROMETER) {
acceleration[0] = event.values[0];
acceleration[1] = event.values[1];
acceleration[2] = event.values[2];
}
if (event.sensor.getType() == Sensor.TYPE_GYROSCOPE) {
rotationRate[0] = event.values[0];
rotationRate[1] = event.values[1];
rotationRate[2] = event.values[2];
}
if (event.sensor.getType() == Sensor.TYPE_MAGNETIC_FIELD) {
magneticField[0] = event.values[0];
magneticField[1] = event.values[1];
magneticField[2] = event.values[2];
}
if (isFirstSet) {
startTime = System.currentTimeMillis();
isFirstSet = false;
}
currentTime = System.currentTimeMillis();
for (int i = 0; i % 1 == 0; i++) {
if (!stopFlag) {
save();
}
else {
try {
myOutWriter.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (NullPointerException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
try {
fOut.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (NullPointerException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
}
}
private void save() {
myPrintWriter.write(currentTime - startTime + " " + acceleration[0] + " " + acceleration[1] + " " + acceleration[2]
+ " " + rotationRate[0] + " " + rotationRate[1] + " " + rotationRate[2]
+ " " + magneticField[0] + " " + magneticField[1] + " " + magneticField[2] + "\n");
}
@Override
protected void onResume() {
super.onResume();
// register this class as a listener for the sensors
sensorManager.registerListener(this, sensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER), SensorManager.SENSOR_DELAY_NORMAL);
sensorManager.registerListener(this, sensorManager.getDefaultSensor(Sensor.TYPE_GYROSCOPE), SensorManager.SENSOR_DELAY_NORMAL);
sensorManager.registerListener(this, sensorManager.getDefaultSensor(Sensor.TYPE_MAGNETIC_FIELD), SensorManager.SENSOR_DELAY_NORMAL);
}
@Override
protected void onPause() {
// unregister listener
super.onPause();
sensorManager.unregisterListener(this);
}
@Override
public void onAccuracyChanged(Sensor arg0, int arg1) {
// TODO Auto-generated method stub
}
}