Android文件读写

Question

It's shows me some letters and numbers when i enter a number in the TextField for example i will type 100 and it gives me letter "d" how can i fix this ? I have this code.

btn.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            int takeMoney = Integer.parseInt(txtEdit.getText().toString());
            String filename = "moneySavings.txt";
            int asd = takeMoney;
            FileOutputStream outputStream;

            try {
                outputStream = openFileOutput(filename, Context.MODE_PRIVATE);
                outputStream.write(asd);
                outputStream.close();
                savings.setText("File Created !");
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    });

    btn2.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {

            FileInputStream fis;
            final StringBuffer storedString = new StringBuffer();

            try {
                fis = openFileInput("moneySavings.txt");
                DataInputStream dataIO = new DataInputStream(fis);
                String strLine = null;

                if((strLine = dataIO.readLine()) != null) {
                    storedString.append(strLine);
                    savings.setText(strLine);
                }
                dataIO.close();
                fis.close();
            }
            catch  (Exception e) {
                e.printStackTrace();
            }
        }
    });

Explain me whats causes this problem and how do i fix it ... thanks :)

Answer 1

100 is the ASCII value for d. Your string value is being type casted to its ASCII value at the OutputStream .

You cannot write strings in OutputStream directly. Try:

outputStream.write(txtEdit.getText().toString().getBytes());

To limit your inputs to numbers, you can specify the keyboard. See the TextFields documentation .

Ex 1:

<EditText
    android:id="@+id/numberInput"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:hint="@string/number_hint"
    android:inputType="number" />

Ex 2 - Phone Dialer Keyboard:

<EditText
    android:id="@+id/numberInput"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:hint="@string/number_hint"
    android:inputType="phone" />

Answer 2

OutputStream.write(int) is writing that int as byte, so if you write .write(100) and later you read as string you will get d since 100 is the ASCII code for d . If you try 101 it then will be e .

If you want to save 100 as "100" then try: How to write Strings to an OutputStream