http://www.masterqna.com/android/20262/%EC%97%90%EB%94%94%ED%8A%B8-%ED%85%8D%EC%8A%A4%ED%8A%B8-%EC%9E%85%EB%A0%A5%ED%95%9C-%EA%B8%80%EC%9E%90-%EC%88%98-%ED%85%8D%EC%8A%A4%ED%8A%B8%EB%B7%B0%EB%A1%9C-%EC%B6%9C%EB%A0%A5%ED%95%98%EA%B8%B0-%EC%A7%88%EB%AC%B8%EC%9E%85%EB%8B%88%EB%8B%A4

if (Strings.isNullOrEmpty(string)) { return 0; }

Strings << 이건 google guava 라이브러리에 있는 스트링 Null or Empty 검사입니다.

string == null || “”.equals(string) 과 같은 메서드죠…

 

그리고 제가 드린 static int getLength 메서드는 글자수를 바이트로 계산해야하는 경우에 사용하는 메서드 입니다.

바이트 계산이 필요없다면 그냥

@Override

public void onTextChanged(CharSequence s, int start, int before,

int count) {

int textLength = s.toString().length();

}

이렇게 얻으시면 되구요.

필요하다면

int textBytes = getLength(s.toString());

이렇게 하시면 됩니다.

package location.androidtown.org.mydoit_chap01_2;

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.text.Editable;
import android.text.TextWatcher;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;

public class TextChangeListener extends AppCompatActivity {

    EditText editText;
    TextView textCount;

    Button transButton, closeBtn;

    int count2=0;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_text_change_listener);


        editText =(EditText)findViewById(R.id.edit_text);
        textCount=(TextView)findViewById(R.id.textCount);



        transButton =(Button)findViewById(R.id.btnTrans);
        closeBtn=(Button)findViewById(R.id.btnClose);

        transButton.setOnClickListener(listener);
        closeBtn.setOnClickListener(listener);

        editText.addTextChangedListener(cWatcher);
       // editText.setFilters(new InputFilter[80]);

    }



    View.OnClickListener listener =new View.OnClickListener() {
        @Override
        public void onClick(View v) {


            switch (v.getId()){


                case R.id.btnTrans:

                    Toast.makeText(getApplicationContext(), editText.getText().toString(), Toast.LENGTH_SHORT).show();


                    break;




                case R.id.btnClose:

                    break;

            }
        }
    };



        TextWatcher cWatcher = new TextWatcher() {

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

               count2=getLength(s.toString());
                textCount.setText(String.valueOf(count2));

             //   Toast.makeText(getApplicationContext(), String.valueOf(count), Toast.LENGTH_SHORT).show();
            }

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


            }

            @Override
            public void afterTextChanged(Editable s) {

            }
        };



        public static int getLength(String string) {

            if (string == null || "".equals(string) ) {
                return 0;
            }
            int length = string.length();
            int charLength = 0;
            for (int i = 0; i < length; i++) {
                charLength += string.codePointAt(i) > 0x00ff ? 2 : 1;

            }
            return charLength;

        }




}