Android開發-DesignDemo-AndroidStudio(十二)TextInputLayout

TextInputActivity.java:

package com.iwanghang.coordinatordemo;

import android.support.design.widget.TextInputLayout;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.text.Editable;
import android.text.TextWatcher;

public class TextInputActivity extends AppCompatActivity implements TextWatcher {
    TextInputLayout text_input;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_text_input);
        text_input = (TextInputLayout) findViewById(R.id.text_input);
        // 監聽editText的內容改變
        // 實現 addTextChangedListener 的 beforeTextChanged onTextChanged
        // afterTextChanged 這3個方法
        text_input.getEditText().addTextChangedListener(this);
    }

    @Override
    public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) {

    }

    @Override
    public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) {

    }

    @Override
    public void afterTextChanged(Editable editable) {
        if (editable.length()<6) {
            text_input.setError("用戶名必須為6位或以上");
            text_input.setErrorEnabled(true);
        } else {
            text_input.setErrorEnabled(false);
        }
    }
}