在Android中的EditText中更改用户输入的字符

Question

I want to change user entered character in a EditText. in fact i want when user types in Edit text, If input character is "S", replaces it with "B" character. i want do this realtime.

Answer 1

I want to change user entered character in a EditText. in fact i want when user types in Edit text, If input character is "S", replaces it with "B" character. i want do this realtime.

Most likely you need to use TextWatcher that it pretty designated for your goal and allows you to manipulate with content of EditText in realtime.

Example:

edittext.addTextChangedListener(new TextWatcher() {

    public void onTextChanged(CharSequence s, int start, int before, int count) {           

    }

    public void beforeTextChanged(CharSequence s, int start, int count, int after) {    

    }

    public void afterTextChanged(Editable s) {

    }
});

Answer 2

Like Sajmon explained, you have to implement a TextWatcher. You have to take care for the cursor. Because the user can input the next character (or a sequence from the clipboard) at any position in the existing text string. To handle this, you have to change the character at the right position (don't replace the whole text):

        damageEditLongText.addTextChangedListener(new TextWatcher() {

        @Override
        public void beforeTextChanged(CharSequence s, int start, int count, int after) {}

        @Override
        public void onTextChanged(CharSequence s, int start, int before, int count) {}

        @Override
        public void afterTextChanged(Editable s) {
            // Nothing to replace
            if (s.length() == 0)
                return;

            // Replace 'S' by 'B'
            String text = s.toString();
            if (Pattern.matches(".*S.*", text)) {
                int pos = text.indexOf("S");
                s.replace(pos, pos + 1, "B");
            }
        }
    });

Answer 3

use

EditText textField = findViewById(R.id.textField);
String text = textField.getText().toString();

then you can use

text.replace('b','s');

followed by

textField.setText(text,TextView.BufferType);

TextView.BufferType can have 3 values as stated here