@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_text_input);textInput = (TextInputLayout) findViewById(R.id.text_input_layout);textInput.getEditText().addTextChangedListener(this);}@Overridepublic void beforeTextChanged(CharSequence s, int start, int count, int after) {}@Overridepublic void onTextChanged(CharSequence s, int start, int before, int count) {}//完成@Overridepublic void afterTextChanged(Editable s) {if(s.length()<6){textInput.setError("密码不能小于6！");textInput.setErrorEnabled(true);}else{textInput.setErrorEnabled(false);}}

<?xml version="1.0" encoding="utf-8"?>
<LinearLayoutxmlns:android="http://schemas.android.com/apk/res/android"xmlns:tools="http://schemas.android.com/tools"android:layout_width="match_parent"android:layout_height="match_parent"android:orientation="vertical"tools:context="com.example.nanchen.designcoodinatordemo.TextInputActivity"><EditTextandroid:layout_width="match_parent"android:hint="输入用户名.."android:layout_height="wrap_content"/><android.support.design.widget.TextInputLayoutandroid:layout_width="match_parent"android:id="@+id/text_input_layout"android:layout_height="wrap_content"><EditTextandroid:layout_width="match_parent"android:hint="输入密码..."android:layout_height="wrap_content"/></android.support.design.widget.TextInputLayout><android.support.design.widget.TextInputEditTextandroid:layout_width="match_parent"android:layout_height="wrap_content"android:hint="邮箱"/></LinearLayout>

package com.example.nanchen.designcoodinatordemo;import android.content.Context;
import android.support.design.widget.CoordinatorLayout;
import android.support.design.widget.FloatingActionButton;
import android.util.AttributeSet;
import android.view.View;/*** 自定义Behavior* Created by 南尘 on 16-7-14.*/
public class MyBehavior extends FloatingActionButton.Behavior {//写了这个构造方法才能在XML文件中直接指定public MyBehavior(Context context, AttributeSet attrs) {super();}@Overridepublic boolean onStartNestedScroll(CoordinatorLayout coordinatorLayout, FloatingActionButton child, View directTargetChild, View target, int nestedScrollAxes) {return true;//返回true代表我们关心这个滚动事件}@Overridepublic void onNestedPreScroll(CoordinatorLayout coordinatorLayout, FloatingActionButton child, View target, int dx, int dy, int[] consumed) {super.onNestedPreScroll(coordinatorLayout, child, target, dx, dy, consumed);if (dy < 0) {//向下滚动
//            ViewCompat.animate(child).scaleX(1).alpha(1).start();child.show();} else {//向上滚动
//            ViewCompat.animate(child).scaleX(0).alpha(0).start();child.hide();}}
}