package com.xdw.a122;import android.support.v7.app.AppCompatActivity;import android.os.Bundle;import android.text.Editable;import android.text.TextWatcher;import android.util.Log;import android.view.View;import android.widget.Button;import android.widget.EditText;import android.widget.Toast;public class EdittextActivity extends AppCompatActivity { private Button mBtnLogin; private EditText mEtUserName; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_edittext); mBtnLogin=findViewById(R.id.btn_login); mBtnLogin.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { Toast.makeText(EdittextActivity.this,"登陆成功!",Toast.LENGTH_LONG).show(); } }); mEtUserName=findViewById(R.id.et_1); mEtUserName.addTextChangedListener(new TextWatcher() { @Override public void beforeTextChanged(CharSequence s, int start, int count, int after) { }//文字改变之前 @Override public void onTextChanged(CharSequence s, int start, int before, int count) { Log.d("edittext",s.toString()); }//文字改变中 @Override public void afterTextChanged(Editable s) { }//文字改变之后 }); }}

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
 xmlns:app="http://schemas.android.com/apk/res-auto"
 xmlns:tools="http://schemas.android.com/tools"
 android:layout_width="match_parent"
 android:layout_height="match_parent"
 tools:context=".EdittextActivity">

 <EditText
 android:id="@+id/et_1"
 android:layout_width="match_parent"
 android:layout_height="50dp"
 android:layout_alignParentStart="true"
 android:layout_alignParentTop="true"
 android:layout_marginStart="0dp"
 android:layout_marginTop="10dp"
 android:background="@drawable/bg_username"
 android:drawableLeft="@drawable/user1"
 android:hint=" 用户名"
 android:inputType="text"
 android:maxLines="1"
 android:paddingLeft="10dp"
 android:paddingRight="10dp"
 android:textColor="#FFAD33"
 android:textSize="16sp" />
 <EditText
 android:id="@+id/et_2"
 android:layout_width="match_parent"
 android:layout_height="50dp"
 android:textSize="16sp"
 android:textColor="#FFAD33"
 android:drawableLeft="@drawable/pass1"
 android:hint=" 密码"
 android:inputType="textPassword"
 android:background="@drawable/bg_username"
 android:layout_below="@+id/et_1"
 android:layout_marginTop="15dp"
 android:paddingLeft="10dp"
 android:paddingRight="10dp"/>
 <Button
 android:id="@+id/btn_login"
 android:layout_width="match_parent"
 android:layout_height="40dp"
 android:layout_marginTop="40dp"
 android:layout_below="@id/et_2"
 android:background="@drawable/bg_btn3"
 android:text="登陆"

 android:textColor="#fff"
 android:textSize="20sp"/>
</RelativeLayout>

private Button mBtnLogin;mBtnLogin=findViewById(R.id.btn_login); mBtnLogin.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { Toast.makeText(EdittextActivity.this,"登陆成功!",Toast.LENGTH_LONG).show(); } });