Preface

The official explanation is that setting an attribute on EditText: android:inputType="textCapWords" capitalizes each word, but it turns out that there is no egg to use. I don't know what's going on. (If you know why, please let me know!) Now let's talk about the plan.

programme

Find an answer on Stakoverflow and use TextWatcher to achieve this goal!
Motorola Bionic - input type textPersonName and textCapWords not working

public class WordUtil {

    public static String capitalize(String str) {
        return capitalize(str, (char[]) null);
    }

    public static String capitalize(String str, char... delimiters) {
        int delimLen = delimiters == null ? -1 : delimiters.length;
        if (!TextUtils.isEmpty(str) && delimLen != 0) {
            char[] buffer = str.toCharArray();
            boolean capitalizeNext = true;

            for (int i = 0; i < buffer.length; ++i) {
                char ch = buffer[i];
                if (isDelimiter(ch, delimiters)) {
                    capitalizeNext = true;
                } else if (capitalizeNext) {
                    buffer[i] = Character.toTitleCase(ch);
                    capitalizeNext = false;
                }
            }

            return new String(buffer);
        } else {
            return str;
        }
    }

    private static boolean isDelimiter(char ch, char[] delimiters) {
        if (delimiters == null) {
            return Character.isWhitespace(ch);
        } else {
            char[] arr$ = delimiters;
            int len$ = delimiters.length;

            for (int i$ = 0; i$ < len$; ++i$) {
                char delimiter = arr$[i$];
                if (ch == delimiter) {
                    return true;
                }
            }

            return false;
        }
    }
}

Then in activity:

TextWatcher capitalizeTW = new TextWatcher() {
    @Override
    public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) {

    }

    @Override
    public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) {
        try{
            String inputString = ""+YOUR_TEXT_VIEW.getText().toString();
            String firstLetterCapString = WordUtil.capitalize(inputString);
            if(!firstLetterCapString.equals(""+YOUR_TEXT_VIEW.getText().toString())){
                YOUR_TEXT_VIEW.setText(""+firstLetterCapString);
                YOUR_TEXT_VIEW.setSelection(YOUR_TEXT_VIEW.getText().length());
            }
        }catch (Exception e){
            e.printStackTrace();
        }
    }

    @Override
    public void afterTextChanged(Editable editable) {

    }
};

Add TextWatcher for EditText:

YOUR_TEXT_VIEW.addTextChangedListener(capitalizeTW);

For TextView, a similar solution can be used, except that you don't need to set up TextWatcher, and you can simply call the relevant code to manually convert it.

Other relevant

Set all capitals

android:textAllCaps="true" is an attribute that capitalizes all letters for TextView, but it cannot be used for EdidText. IndexOutOfBoundsException is erroneously set in xml and is useless in code. If you want to type all capitals in EditText, you'll think of android: inputType= "tCapacters", but it's useless. It's the same property that doesn't have any eggs to use. So the corresponding solution:
Solution 1: Similarly, we can use the method of adding TextWatcher above to solve the problem.
Scheme 2: Refer to this article: Setting EditText to enter all text in capitals or lowercases

In Button, if there is English in text, it will default to all capitals. We can set textAllCaps to false and make it lowercase!

inputType attribute of EditText

    //Text type, mostly capitals, lowercase and numeric numbers.
    android:inputType="none"
    android:inputType="text"
    android:inputType="textCapCharacters" //Capital letters
    android:inputType="textCapWords" //title case
    android:inputType="textCapSentences" //Only the first letter is capitalized
    android:inputType="textAutoCorrect" //Automatic completion
    android:inputType="textAutoComplete" //Automatic completion
    android:inputType="textMultiLine" //Multi-line input
    android:inputType="textImeMultiLine" //Input method with multiple lines (if supported)
    android:inputType="textNoSuggestions" //No prompt
    android:inputType="textUri" //Website
    android:inputType="textEmailAddress" //E-mail address
    android:inputType="textEmailSubject" //Mail Subject
    android:inputType="textShortMessage" //SMS
    android:inputType="textLongMessage" //Long message
    android:inputType="textPersonName" //Name
    android:inputType="textPostalAddress" //address
    android:inputType="textPassword" //Password
    android:inputType="textVisiblePassword" //Visible password
    android:inputType="textWebEditText" //Text as a Web Form
    android:inputType="textFilter" //Text filtering
    android:inputType="textPhonetic" //Pinyin input//numeric type
    android:inputType="number"// number
    android:inputType="numberSigned" //Symbolized numeric format
    android:inputType="numberDecimal" //Floating-point scheme with decimal point
    android:inputType="phone" //Dial-up keyboard
    android:inputType="datetime" //Time and date
    android:inputType="date" //Date keyboard
    android:inputType="time" //Time Keyboard