TextInputLayout输入框验证

<!--
通过修改<color name="colorAccent">#023cfa</color>可以修改正确提示文本的颜色
添加<item name="android:textColorPrimary">@color/textColorPrimary</item>属性可以修改输入文本的颜色
-->
<android.support.design.widget.TextInputLayout
    android:id="@+id/text_input_layout"
    android:layout_width="match_parent"
    android:layout_height="wrap_content">

    <EditText
        android:layout_width="match_parent"
        android:layout_height="48dp"/>
</android.support.design.widget.TextInputLayout>

public class MainActivity extends AppCompatActivity {

    private TextInputLayout textInputLayout;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        textInputLayout = (TextInputLayout) findViewById(R.id.text_input_layout);
        textInputLayout.setHint("请输入邮箱地址");
        //获取到TextInputLayout包裹的EditText
        EditText editText = textInputLayout.getEditText();
        editText.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) {
                //如果不包含@认为是非法邮箱地址
                if (!s.toString().contains("@")) {
                    //允许TextInputLayout显示错误信息
                    textInputLayout.setErrorEnabled(true);
                    //设置错误信息
                    textInputLayout.setError("邮箱地址非法");
                } else {
                    textInputLayout.setErrorEnabled(false);
                }
            }
        });
    }
}