Android06——实现简单的登录功能

一、简介

二、效果图

三、核心代码

 1. activity_login.xml

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns: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=".LoginActivity">

<TextView

android:id="@+id/sign"

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:text="用户登录"

android:gravity="center"

android:textStyle="bold"

android:textSize="20sp"

/>

<RelativeLayout

android:id="@+id/main"

android:layout_width="match_parent"

android:layout_height="match_parent">

<TextView

android:id="@+id/userLabel"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:layout_below="@id/userLabel"

android:layout_alignBaseline="@id/userNameText"

android:text="用户名："

android:textSize="20sp"/>

<EditText

android:id="@+id/userNameText"

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:layout_toRightOf="@id/userLabel"

android:textSize="20sp"

android:hint="请输入用户名"/>

<TextView

android:id="@+id/pswLabel"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:layout_below="@id/userNameText"

android:layout_alignBaseline="@id/passwordText"

android:textSize="20sp"

android:text="密 码："/>

<EditText

android:id="@+id/passwordText"

android:layout_width="250dp"

android:layout_height="wrap_content"

android:layout_below="@id/userNameText"

android:layout_toRightOf="@id/pswLabel"

android:layout_alignLeft="@id/userNameText"

android:inputType="textPassword"

android:textSize="20sp"

android:hint="请输入密码"/>

<ToggleButton

android:id="@+id/showPwd"

android:layout_width="25dp"

android:layout_height="25dp"

android:layout_toRightOf="@id/passwordText"

android:layout_below="@id/userNameText"

android:layout_alignBaseline="@id/passwordText"

android:background="@drawable/close"

android:textOn=""

android:textOff=""/>

<TextView

android:id="@+id/register"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:layout_below="@id/passwordText"

android:layout_alignBaseline="@id/loginBtn"

android:textSize="15sp"

android:layout_marginLeft="20dp"

android:text="注册"

android:clickable="true"/>

<Button

android:id="@+id/resetBtn"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:text="重置"

android:layout_below="@id/passwordText"

android:layout_toRightOf="@id/register"

android:layout_marginLeft="100dp"

android:textSize="20sp"

android:textStyle="bold"/>

<Button

android:id="@+id/loginBtn"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:layout_below="@id/passwordText"

android:layout_toRightOf="@id/resetBtn"

android:layout_alignRight="@id/passwordText"

android:textSize="20sp"

android:textStyle="bold"

android:text="登录"/>

</RelativeLayout>

</LinearLayout>

2. LoginActivity.java

package com.kjgym.demologin01;

import android.support.v7.app.AppCompatActivity;

import android.os.Bundle;

import android.text.method.HideReturnsTransformationMethod;

import android.text.method.PasswordTransformationMethod;

import android.view.View;

import android.widget.Button;

import android.widget.CompoundButton;

import android.widget.EditText;

import android.widget.TextView;

import android.widget.Toast;

import android.widget.ToggleButton;

public class LoginActivity extends AppCompatActivity {

private Button resetBtn;

private Button loginBtn;

private TextView register;

private EditText userNameText;

private EditText passwordText;

private ToggleButton showPwd;

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_login);

init();

}

public void init(){

resetBtn = findViewById(R.id.resetBtn);

loginBtn = findViewById(R.id.loginBtn);

register = findViewById(R.id.register);

userNameText = findViewById(R.id.userNameText);

passwordText = findViewById(R.id.passwordText);

showPwd = findViewById(R.id.showPwd);

showPwd.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {

@Override

public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {

if(isChecked){

showPwd.setBackgroundResource(R.drawable.open);

passwordText.setTransformationMethod(HideReturnsTransformationMethod.getInstance());

passwordText.setSelection(passwordText.getText().toString().length());

}else{

showPwd.setBackgroundResource(R.drawable.close);

passwordText.setTransformationMethod(PasswordTransformationMethod.getInstance());

passwordText.setSelection(passwordText.getText().toString().length());

}

}

});

loginBtn.setOnClickListener(new View.OnClickListener() {

@Override

public void onClick(View v) {

Toast.makeText(getApplicationContext(),"登录功能尚未实现",Toast.LENGTH_LONG).show();

}

});

register.setOnClickListener(new View.OnClickListener() {

@Override

public void onClick(View v) {

Toast.makeText(getApplicationContext(),"注册功能尚未实现",Toast.LENGTH_LONG).show();

}

});

resetBtn.setOnClickListener(new View.OnClickListener(){

@Override

public void onClick(View v){

userNameText.setText("");

passwordText.setText("");

showPwd.setBackgroundResource(R.drawable.close);

}

});

}

}