Android Edittext implements inputting lowercase letters to display uppercase letters

You can use the setFilters method with InputFilter to achieve this function

• Here is a simple example:

EditText editText = (EditText) findViewById(R.id.edit_text);
InputFilter filter = new InputFilter() {
    
    
    public CharSequence filter(CharSequence source, int start, int end, Spanned dest, int dstart, int dend) {
    
    
        for (int i = start; i < end; i++) {
    
    
            if (Character.isLowerCase(source.charAt(i))) {
    
    
                char[] v = new char[end - start];
                TextUtils.getChars(source, start, end, v, 0);
                String s = new String(v).toUpperCase();

                return s;
            }
        }
        return null;
    }
};
editText.setFilters(new InputFilter[] {
    
     filter });

In this example, we created a custom InputFilter that converts all lowercase letters to uppercase letters. We then apply this filter to the EditText so that every time a lowercase letter is entered, an uppercase letter is displayed.