无法打开堆栈跟踪文件'/data/anr/traces.txt'：授予权限时权限被拒绝

Question

我正在用Eclipse编写一个Android应用程序，如果我按如下方式编写应用程序，一切正常：

import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.Reader;
import java.io.Writer;
import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.widget.EditText;

public class HTableActivity extends Activity {

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
    }

    public boolean onCreateOptionsMenu(Menu menu){
        super.onCreateOptionsMenu(menu);
        MenuInflater inflater = getMenuInflater();
        inflater.inflate(R.menu.mymenu, menu);
        return true;
    }

    public boolean onOptionsItemSelected(MenuItem item){
        if (item.getItemId() == R.id.save_item){
            save("testo.txt");
            return true;
        } else if (item.getItemId() == (R.id.load_item)) {
            load("testo.txt");
            return true;
        } else
            return false;
    }

    private void save(String filename){

        StringBuffer aux = new StringBuffer();
        Writer writer = null; //scrittore

        EditText[] textAreas = new EditText[3];
        textAreas[0] = (EditText) findViewById(R.id.editText1);
        textAreas[1] = (EditText) findViewById(R.id.editText2);
        textAreas[2] = (EditText) findViewById(R.id.editText3); 

        for(EditText et : textAreas){
            aux.append( et.getText().toString() + "\n");
        }

        try{
            writer = new OutputStreamWriter(this.openFileOutput(filename, MODE_PRIVATE));
            writer.write(aux.toString());
        }catch (IOException e){
            Log.e("Hash Table", "Impossibile salvare il file", e);
        }
        finally{
            if (writer != null){
                try { 
                    writer.close(); 
                } catch (Throwable t) {
                    Log.e("Hash Table", "Impossibile chiudere il file", t);
                }
            }
        }
    }

    private void load(String filename){

        StringBuffer aux = new StringBuffer();
        Reader reader = null;
        String[] splits;
        int i=0;

        EditText[] textAreas = new EditText[3];
        textAreas[0] = (EditText) findViewById(R.id.editText1);
        textAreas[1] = (EditText) findViewById(R.id.editText2);
        textAreas[2] = (EditText) findViewById(R.id.editText3); 

        try{
            reader = new InputStreamReader(openFileInput(filename));
            char[] buf = new char[1024];

            int len;

            while ((len = reader.read(buf)) != -1) {
                aux.append(buf, 0, len);
            }
            splits = aux.toString().split("\\n");
            for(EditText et : textAreas){
                et.setText(splits[i++]);
            }

        } catch (FileNotFoundException e) {
            Log.e("Hash Table", "File non trovato", e);
        } catch (IOException e) {
            Log.e("Hash Table", "Impossibile aprire il file", e);
        } finally {
            if (reader != null) {
                try {
                    reader.close(); 
                } catch (Throwable t) {
                    Log.e("Hash Table", "Impossibile chiudere il file", t);
                }
            }
        }
    }
}

但考虑到以下变量：

    EditText[] textAreas = new EditText[3];
    textAreas[0] = (EditText) findViewById(R.id.editText1);
    textAreas[1] = (EditText) findViewById(R.id.editText2);
    textAreas[2] = (EditText) findViewById(R.id.editText3); 

在加载方法中出现比在save中出现，我想让它们“全局”如下：

import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.Reader;
import java.io.Writer;
import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.widget.EditText;

    public class HTableActivity extends Activity {

       public EditText textAreas;

       HTableActivity (){
            textAreas = new EditText[3];
            textAreas[0] = (EditText) findViewById(R.id.editText1);
            textAreas[1] = (EditText) findViewById(R.id.editText2);
            textAreas[2] = (EditText) findViewById(R.id.editText3); 
        }

        /** Called when the activity is first created. */
        @Override
        public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.main);
        }

        public boolean onCreateOptionsMenu(Menu menu){
            super.onCreateOptionsMenu(menu);
            MenuInflater inflater = getMenuInflater();
            inflater.inflate(R.menu.mymenu, menu);
            return true;
        }

        public boolean onOptionsItemSelected(MenuItem item){
            if (item.getItemId() == R.id.save_item){
                save("testo.txt");
                return true;
            } else if (item.getItemId() == (R.id.load_item)) {
                load("testo.txt");
                return true;
            } else
                return false;
        }

        private void save(String filename){

            StringBuffer aux = new StringBuffer();
            Writer writer = null;

            for(EditText et : textAreas){
                aux.append( et.getText().toString() + "\n");
            }

            try{
                writer = new OutputStreamWriter(this.openFileOutput(filename, MODE_PRIVATE));
                writer.write(aux.toString());
            }catch (IOException e){
                Log.e("Hash Table", "Impossibile salvare il file", e);
            }
            finally{
                if (writer != null){
                    try { 
                        writer.close(); 
                    } catch (Throwable t) {
                        Log.e("Hash Table", "Impossibile chiudere il file", t);
                    }
                }
            }
        }

        private void load(String filename){

            StringBuffer aux = new StringBuffer();
            Reader reader = null;
            String[] splits;
            int i=0;

            try{
                reader = new InputStreamReader(openFileInput(filename));
                char[] buf = new char[1024];

                int len;

                while ((len = reader.read(buf)) != -1) {
                    aux.append(buf, 0, len);
                }
                splits = aux.toString().split("\\n");
                for(EditText et : textAreas){
                    et.setText(splits[i++]);
                }

            } catch (FileNotFoundException e) {
                Log.e("Hash Table", "File non trovato", e);
            } catch (IOException e) {
                Log.e("Hash Table", "Impossibile aprire il file", e);
            } finally {
                if (reader != null) {
                    try {
                        reader.close(); 
                    } catch (Throwable t) {
                        Log.e("Hash Table", "Impossibile chiudere il file", t);
                    }
                }
            }
        }
    }

我还添加了权限：

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

在Android清单中

，但尽管如此，当我启动应用程序时，我收到以下错误：

E/dalvikvm(384): Unable to open stack trace file '/data/anr/traces.txt': Permission denied

有人可以解释为什么这种代码更改会导致此错误吗？

Full StackTrace：

[2012-05-27 13:11:00 - HTable] ------------------------------
[2012-05-27 13:11:00 - HTable] Android Launch!
[2012-05-27 13:11:00 - HTable] adb is running normally.
[2012-05-27 13:11:00 - HTable] Performing corso.terminali.HTableActivity activity launch
[2012-05-27 13:11:00 - HTable] Automatic Target Mode: using existing emulator 'emulator-5554' running compatible AVD 'MyDevice1.6'
[2012-05-27 13:11:00 - HTable] Uploading HTable.apk onto device 'emulator-5554'
[2012-05-27 13:11:00 - HTable] Installing HTable.apk...
[2012-05-27 13:11:03 - HTable] Success!
[2012-05-27 13:11:03 - HTable] Starting activity corso.terminali.HTableActivity on device emulator-5554
[2012-05-27 13:11:05 - HTable] ActivityManager: Starting: Intent { act=android.intent.action.MAIN cat=[android.intent.category.LAUNCHER] cmp=corso.terminali/.HTableActivity }

我还在与eclipse集成的Android模拟器（1.6版）中实现了512 MB的虚拟SD卡。

我一直在努力，我得出的结论是，您可以在全局范围内声明和初始化数组textareas（EditText textareas EditText＆gt; = new [n]），但是您无法执行全局赋值ID，在构造函数中，在方法“public void onCreate＆gt;（）”中，当方法“save”和“load”为＆gt;时会导致错误调用。因此，虽然我不了解原因，但我认为＆gt;最好的解决方案是全局声明数组“textareas”，＆gt;然后在两种形式'保存'和'加载'中继续分配ID“textareas [n] =（EditText）＆gt; findViewById（R.Id.editTextn）”。如果＆gt;有人知道为什么会这样，请告诉我。

---

我一直在努力，我得出的结论是，您可以在全局范围内声明和初始化数组textareas（EditText textareas EditText＆gt; = new [n]），但是您无法执行ID的全局分配，在构造函数中，在方法“public void onCreate＆gt;（）”中，当方法“save”和“load”为＆gt;时会导致错误。调用。因此，虽然我不了解原因，但我认为＆gt;最好的解决方案是全局声明数组“textareas”，＆gt;然后在两种形式'保存'和'加载'中继续分配ID“textareas [n] =（EditText）＆gt; findViewById（R.Id.editTextn）”。如果＆gt;谁知道为什么会这样，请告诉我。