【发布时间】：2012-07-11 17:30:07
【问题描述】：
我正在尝试将数据从 EditText 字段写入文本文件。我已验证数据正在被捕获以在单击“添加”按钮后填充的 EditText 字段中输出。程序在模拟器中成功运行，但没有创建输出文件。我已将 uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" 添加到 Android Manifest xml 文件中。 LogCat 和控制台不显示任何错误。在这里研究示例后，我尝试了几种不同的方法，但没有运气。谁能指出我的问题？提前感谢您的帮助。
package john.BRprogram;
import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.WindowManager;
import android.view.View.OnClickListener;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.Spinner;
import android.widget.AdapterView.OnItemSelectedListener;
import android.widget.EditText;
//import android.graphics.Color;
import java.io.OutputStreamWriter;
import java.util.Scanner;
import java.util.List;
import java.util.ArrayList;
public class BRprogramActivity extends Activity implements OnItemSelectedListener {
private static final String TAG = null;
//
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
//
Button addButton;
Button editButton;
Button sendButton;
//
Spinner array_spinner;
//
// activate soft Keyboard
this.getWindow().setSoftInputMode
(WindowManager.LayoutParams.SOFT_INPUT_STATE_ALWAYS_VISIBLE);
//
EditText myCustomer = (EditText)findViewById(R.id.editText1);
myCustomer.setText("");
//
EditText myQuantity = (EditText)findViewById(R.id.editText2);
myQuantity.setText("");
//
EditText myPrice = (EditText)findViewById(R.id.editText3);
myPrice.setText("");
//
// .csv comma separated values file
//
try {
Scanner scanner = new Scanner(getResources().openRawResource(R.raw.brdata));
//
List<String> list = new ArrayList<String>();
while (scanner.hasNext()) {
String data = (scanner.next()); //read data record
String [] values = data.split(","); //parse data to fields
// String [] values = data.split(",(?=([^\"]\"[^\"]\")[^\"]$)");
if(values.length != 3)
Log.v("Example", "Malformed row: " + data);
else
list.add(values[0] + " " + values[1] + " $" + values[2]);
}
//
array_spinner = (Spinner)findViewById(R.id.spinner1);
ArrayAdapter<String> adapter = new ArrayAdapter<String>
(this,android.R.layout.simple_spinner_item, list);
adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
array_spinner.setAdapter(adapter);
array_spinner.setOnItemSelectedListener((OnItemSelectedListener) this);
//
scanner.close();
//
} catch (Exception e) {
Log.e(TAG, "Exception: "+Log.getStackTraceString(e));
}
//
addButton = (Button) findViewById(R.id.addbutton);
addButton.setOnClickListener(new OnClickListener(){
public void onClick(View v){
//
// get customer number,itemnumber,quantity,price
//
String writeCustomer = ((EditText) findViewById(R.id.editText1)).getText().toString().trim();
// itemNumber from list selection
String writeQuantity = ((EditText) findViewById(R.id.editText2)).getText().toString().trim();
String writePrice = ((EditText) findViewById(R.id.editText3)).getText().toString().trim();
//
String newRecord = writeCustomer + "," + writeQuantity + "," + writePrice;
EditText myString = (EditText)findViewById(R.id.editText4);
myString.setText(newRecord);
//
// write seq to output file
//
try {
OutputStreamWriter out = new OutputStreamWriter(openFileOutput("broutput.txt",0));
out.write(newRecord);
out.close();
}catch (Exception e){
Log.v("test", "record written");
}
//
EditText myQuantity = (EditText)findViewById(R.id.editText2);
myQuantity.setText("");
//
EditText myPrice = (EditText)findViewById(R.id.editText3);
myPrice.setText("");
Log.v("test", "ADD button clicked");
}
});
//
editButton = (Button) findViewById(R.id.editbutton);
editButton.setOnClickListener(new OnClickListener(){
public void onClick(View v){
Log.v("test", "EDIT button clicked");
}
});
//
sendButton = (Button) findViewById(R.id.sendbutton);
sendButton.setOnClickListener(new OnClickListener(){
public void onClick(View v){
//
EditText myCustomer = (EditText)findViewById(R.id.editText1);
myCustomer.setText("");
//
EditText myQuantity = (EditText)findViewById(R.id.editText2);
myQuantity.setText("");
//
EditText myPrice = (EditText)findViewById(R.id.editText3);
myPrice.setText("");
Log.v("test", "SEND button clicked");
}
});
}
// *** http://www.youtube.com/watch?v=Pfasw0bbe_4 ***
//
public void onItemSelected(AdapterView<?> parent, View view, int position,
long id) {
//
String selection = parent.getItemAtPosition(position).toString();
String [] priceField = selection.split("\\$"); //parse price field
String [] item = selection.split("_"); //parse item number
String itemNumber = item[0];
//
EditText myQuantity = (EditText)findViewById(R.id.editText2);
myQuantity.setText("");
//
EditText myPrice = (EditText)findViewById(R.id.editText3);
myPrice.setText(priceField[1]);
}
//
public void onNothingSelected(AdapterView<?> arg0) {
//nothing here
}
}
【问题讨论】：
-
我认为您不需要 WRITE_EXTERNAL_STORAGE 权限，因为您只是在写入应用程序私有的文件。如果是这种情况，您通常无法在文件管理器中导航到该文件，因为它是您的应用程序私有的。你100%确定它不是被创造出来的吗？抛出了什么
Exception，如果有的话？顺便说一句，最好使用常量名，而不是它们的整数值，所以当你打开文件时，使用openFileOutput("broutput.txt", Context.MODE_PRIVATE);。