Material Design风格登录注册

本文实现了以下功能

完整的代码和样例托管在Github
当接口锁定时，防止后退按钮显示在登录Activity 上。
自定义 ProgressDialog来显示加载的状态。
符合材料设计规范。
悬浮标签（floating labels）（来自设计支持库）
用户表单输入校验
自定义状态栏样式
在每一个Activity 测试模仿验证的方法。

剩下的就是实现自己的身份验证逻辑。

源码

登录Activity

如果你想要添加社交登录按钮，请继续，但是当前在这个文章范围内，只给你基本的代码，让你有一个坚固的起点去构建你的验证流程。需要注意的是 onBackPressed 方法将会被重写，这样将会防止用户关闭登录Activity。

 @Override
    public void onBackPressed() {
        // Disable going back to the MainActivity
        moveTaskToBack(true);
    }

moveTaskToBack用户在按返回键的时候你并不希望退出（默认就finish了），而是只希望置后台，就可以调这个方法

参考链接

moveTaskToback退后台 - Android探索之路 - 博客频道 - CSDN.NET

LoginActivity

package com.sourcey.materiallogindemo;

import android.app.ProgressDialog;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;

import android.content.Intent;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;

import butterknife.ButterKnife;
import butterknife.Bind;

public class LoginActivity extends AppCompatActivity {
    private static final String TAG = "LoginActivity";
    private static final int REQUEST_SIGNUP = 0;

    @Bind(R.id.input_email) EditText _emailText;
    @Bind(R.id.input_password) EditText _passwordText;
    @Bind(R.id.btn_login) Button _loginButton;
    @Bind(R.id.link_signup) TextView _signupLink;
    
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_login);
        ButterKnife.bind(this);
        
        _loginButton.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {
                login();
            }
        });

        _signupLink.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {
                // Start the Signup activity
                Intent intent = new Intent(getApplicationContext(), SignupActivity.class);
                startActivityForResult(intent, REQUEST_SIGNUP);
            }
        });
    }

    public void login() {
        Log.d(TAG, "Login");

        if (!validate()) {
            onLoginFailed();
            return;
        }

        _loginButton.setEnabled(false);

        final ProgressDialog progressDialog = new ProgressDialog(LoginActivity.this,
                R.style.AppTheme_Dark_Dialog);
        progressDialog.setIndeterminate(true);
        progressDialog.setMessage("Authenticating...");
        progressDialog.show();

        String email = _emailText.getText().toString();
        String password = _passwordText.getText().toString();

        // TODO: Implement your own authentication logic here.

        new android.os.Handler().postDelayed(
                new Runnable() {
                    public void run() {
                        // On complete call either onLoginSuccess or onLoginFailed
                        onLoginSuccess();
                        // onLoginFailed();
                        progressDialog.dismiss();
                    }
                }, 3000);
    }


    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        if (requestCode == REQUEST_SIGNUP) {
            if (resultCode == RESULT_OK) {

                // TODO: Implement successful signup logic here
                // By default we just finish the Activity and log them in automatically
                this.finish();
            }
        }
    }

    @Override
    public void onBackPressed() {
        // Disable going back to the MainActivity
        moveTaskToBack(true);
    }

    public void onLoginSuccess() {
        _loginButton.setEnabled(true);
        finish();
    }

    public void onLoginFailed() {
        Toast.makeText(getBaseContext(), "Login failed", Toast.LENGTH_LONG).show();

        _loginButton.setEnabled(true);
    }

    public boolean validate() {
        boolean valid = true;

        String email = _emailText.getText().toString();
        String password = _passwordText.getText().toString();

        if (email.isEmpty() || !android.util.Patterns.EMAIL_ADDRESS.matcher(email).matches()) {
            _emailText.setError("enter a valid email address");
            valid = false;
        } else {
            _emailText.setError(null);
        }

        if (password.isEmpty() || password.length() < 4 || password.length() > 10) {
            _passwordText.setError("between 4 and 10 alphanumeric characters");
            valid = false;
        } else {
            _passwordText.setError(null);
        }

        return valid;
    }
}

res/layout/activity_login.xml

<?xml version="1.0" encoding="utf-8"?>
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:fitsSystemWindows="true">

    <LinearLayout
        android:orientation="vertical"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:paddingTop="56dp"
        android:paddingLeft="24dp"
        android:paddingRight="24dp">

        <ImageView android:src="@drawable/logo"
            android:layout_width="wrap_content"
            android:layout_height="72dp"
            android:layout_marginBottom="24dp"
            android:layout_gravity="center_horizontal" />

        <!--  Email Label -->
        <android.support.design.widget.TextInputLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="8dp"
            android:layout_marginBottom="8dp">
            <EditText android:id="@+id/input_email"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:inputType="textEmailAddress"
                android:hint="Email" />
        </android.support.design.widget.TextInputLayout>

        <!--  Password Label -->
        <android.support.design.widget.TextInputLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="8dp"
            android:layout_marginBottom="8dp">
            <EditText android:id="@+id/input_password"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:inputType="textPassword"
                android:hint="Password"/>
        </android.support.design.widget.TextInputLayout>

        <android.support.v7.widget.AppCompatButton
            android:id="@+id/btn_login"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="24dp"
            android:layout_marginBottom="24dp"
            android:padding="12dp"
            android:text="Login"/>

        <TextView android:id="@+id/link_signup"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:layout_marginBottom="24dp"
            android:text="No account yet? Create one"
            android:gravity="center"
            android:textSize="16dip"/>

    </LinearLayout>
</ScrollView>

注册Activity

注册Activity 可以让你在App 中创建一个用户，通常会在登录Activity 中显示（注册的）链接。

需要注意的是当用户注册成功时我们会设置一个RESULT_OK 的结果值，这个结果将会在登录Activity 中的 onActivityResult 方法中调用，并且确定注册成功是如何处理的。当前逻辑是很简单的，当用户注册成功时我们会马上做一个记录。当然你想要实现邮箱验证，你需要自己来实现。

SignupActivity.java

package com.sourcey.materiallogindemo;

import android.app.ProgressDialog;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;

import butterknife.ButterKnife;
import butterknife.Bind;

public class SignupActivity extends AppCompatActivity {
    private static final String TAG = "SignupActivity";

    @Bind(R.id.input_name) EditText _nameText;
    @Bind(R.id.input_email) EditText _emailText;
    @Bind(R.id.input_password) EditText _passwordText;
    @Bind(R.id.btn_signup) Button _signupButton;
    @Bind(R.id.link_login) TextView _loginLink;
    
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_signup);
        ButterKnife.bind(this);

        _signupButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                signup();
            }
        });

        _loginLink.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                // Finish the registration screen and return to the Login activity
                finish();
            }
        });
    }

    public void signup() {
        Log.d(TAG, "Signup");

        if (!validate()) {
            onSignupFailed();
            return;
        }

        _signupButton.setEnabled(false);

        final ProgressDialog progressDialog = new ProgressDialog(SignupActivity.this,
                R.style.AppTheme_Dark_Dialog);
        progressDialog.setIndeterminate(true);
        progressDialog.setMessage("Creating Account...");
        progressDialog.show();

        String name = _nameText.getText().toString();
        String email = _emailText.getText().toString();
        String password = _passwordText.getText().toString();

        // TODO: Implement your own signup logic here.

        new android.os.Handler().postDelayed(
                new Runnable() {
                    public void run() {
                        // On complete call either onSignupSuccess or onSignupFailed
                        // depending on success
                        onSignupSuccess();
                        // onSignupFailed();
                        progressDialog.dismiss();
                    }
                }, 3000);
    }


    public void onSignupSuccess() {
        _signupButton.setEnabled(true);
        setResult(RESULT_OK, null);
        finish();
    }

    public void onSignupFailed() {
        Toast.makeText(getBaseContext(), "Login failed", Toast.LENGTH_LONG).show();

        _signupButton.setEnabled(true);
    }

    public boolean validate() {
        boolean valid = true;

        String name = _nameText.getText().toString();
        String email = _emailText.getText().toString();
        String password = _passwordText.getText().toString();

        if (name.isEmpty() || name.length() < 3) {
            _nameText.setError("at least 3 characters");
            valid = false;
        } else {
            _nameText.setError(null);
        }

        if (email.isEmpty() || !android.util.Patterns.EMAIL_ADDRESS.matcher(email).matches()) {
            _emailText.setError("enter a valid email address");
            valid = false;
        } else {
            _emailText.setError(null);
        }

        if (password.isEmpty() || password.length() < 4 || password.length() > 10) {
            _passwordText.setError("between 4 and 10 alphanumeric characters");
            valid = false;
        } else {
            _passwordText.setError(null);
        }

        return valid;
    }
}

res/layout/activity_signup.xml

<?xml version="1.0" encoding="utf-8"?>
<ScrollView
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:fitsSystemWindows="true">

    <LinearLayout
        android:orientation="vertical"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:paddingTop="56dp"
        android:paddingLeft="24dp"
        android:paddingRight="24dp">

        <ImageView android:src="@drawable/logo"
            android:layout_width="wrap_content"
            android:layout_height="72dp"
            android:layout_marginBottom="24dp"
            android:layout_gravity="center_horizontal" />

        <!-- Name Label -->
        <android.support.design.widget.TextInputLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="8dp"
            android:layout_marginBottom="8dp">
            <EditText android:id="@+id/input_name"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:inputType="textCapWords"
                android:hint="Name" />
        </android.support.design.widget.TextInputLayout>

        <!--  Email Label -->
        <android.support.design.widget.TextInputLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="8dp"
            android:layout_marginBottom="8dp">
            <EditText android:id="@+id/input_email"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:inputType="textEmailAddress"
                android:hint="Email" />
        </android.support.design.widget.TextInputLayout>

        <!-- Password Label -->
        <android.support.design.widget.TextInputLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="8dp"
            android:layout_marginBottom="8dp">
            <EditText android:id="@+id/input_password"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:inputType="textPassword"
                android:hint="Password"/>
        </android.support.design.widget.TextInputLayout>

        <!-- Signup Button -->
        <android.support.v7.widget.AppCompatButton
            android:id="@+id/btn_signup"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="24dp"
            android:layout_marginBottom="24dp"
            android:padding="12dp"
            android:text="Create Account"/>

        <TextView android:id="@+id/link_login"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:layout_marginBottom="24dp"
            android:text="Already a member? Login"
            android:gravity="center"
            android:textSize="16dip"/>

    </LinearLayout>
</ScrollView>

配置

为了让程序一切正常工作，我们在需要在 app 目录下的 build.gradle 中添加一些依赖，ButterKnife 是可选的，当然我们更喜欢用它让我们的Java 代码更加整洁一些。

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    compile 'com.android.support:appcompat-v7:22.2.0'
    compile 'com.android.support:design:22.2.0'
    compile 'com.jakewharton:butterknife:7.0.1'
}

本文中使用了ButterKnife

也就是 findViewById()，一直以来的做法都是一个个定义，然后在 setContentView() 或 inflate() 之后一一来findViewById()进行实例化，而使用 ButterKnife，你只需要在代码中使用注解方式进行对象申明，然后在 setContentView() 或 inflate() 之后调用一句话，那么申明的所有对象自动创建出来。

 @Bind(R.id.input_email) EditText _emailText;
    @Bind(R.id.input_password) EditText _passwordText;
    @Bind(R.id.btn_login) Button _loginButton;
    @Bind(R.id.link_signup) TextView _signupLink;

 ButterKnife.bind(this);

参考链接

原文链接

教你写一个炫酷的Material Design 风格的登录和注册页面