页面登录

一、建立布局文件：activity_login.xml

<?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:id="@+id/activity_login"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:paddingBottom="@dimen/activity_vertical_margin"    android:paddingLeft="@dimen/activity_horizontal_margin"    android:paddingRight="@dimen/activity_horizontal_margin"    android:paddingTop="@dimen/activity_vertical_margin"    android:background="@drawable/loginbg"    tools:context="cn.edn.bzu.case_login.LoginActivity">    <include layout="@layout/login_top"></include>    <ImageView        android:layout_width="wrap_content"        android:layout_height="wrap_content"        app:srcCompat="@drawable/deer"        android:layout_alignParentBottom="true"        android:layout_alignParentRight="true"        android:layout_alignParentEnd="true"        android:layout_marginRight="28dp"        android:layout_marginEnd="28dp"        android:layout_marginBottom="16dp"        android:id="@+id/imageView" /></RelativeLayout>

这个布局文件中并没有对相应的控件进行设置，这个页面主要完成背景和样式然后将其他页面加载到此页面中。

Android:background=”@drawable/loginbg”引用了自己设置的背景 loginbg.xml如下

<?xml version="1.0" encoding="utf-8"?><shape xmlns:android="http://schemas.android.com/apk/res/android">    <gradient        android:startColor="#FFACDAE5"        android:endColor="#FF72CAE1"        android:angle="45"        /></shape>
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注意：<include layout="@layout/login_top"></include>的作用时将login_top.xml加载到该布局文件中。

二、建立布局文件：login_top.xml

<?xml version="1.0" encoding="utf-8"?><RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="match_parent"    android:layout_height="wrap_content"    android:background="@drawable/logintop_roundbg"    android:padding="@dimen/activity_horizontal_margin">    <EditText        android:id="@+id/etName"        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:ems="10"        android:background="@android:drawable/edit_text"        android:drawableLeft="@drawable/icon_user"        android:hint="@string/etName"        >        <requestFocus/>        </EditText>    <EditText        android:id="@+id/etPassword"        android:layout_below="@id/etName"        android:inputType="textPassword"        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:ems="10"        android:background="@android:drawable/edit_text"        android:drawableLeft="@drawable/icon_pass"        android:hint="@string/etPass"        >        <requestFocus/>    </EditText>    <LinearLayout        android:layout_below="@id/etPassword"        android:layout_width="match_parent"        android:layout_height="wrap_content">        <CheckBox            android:id="@+id/cbIsRememberPass"            android:layout_width="0dp"            android:layout_height="wrap_content"            android:layout_weight="1"            android:text="记住密码"            android:textSize="20sp"/>        <Button            android:id="@+id/button"            android:layout_width="0dp"            android:layout_height="wrap_content"            android:layout_weight="1"            android:background="@drawable/btn_select"            android:text="@string/btnLogin"            android:onClick="login"/>    </LinearLayout></RelativeLayout>
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这个布局文件主要设置了控件，控件添加了自己的样式相应的布局文件（从上到下）

（1）.logintop_roundbg.xml

<?xml version="1.0" encoding="utf-8"?><shape xmlns:android="http://schemas.android.com/apk/res/android" android:shape="rectangle">    <corners android:radius="10dp"></corners>    <solid android:color="#55FFFFFF"></solid></shape>
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（2）.btn_select.xml

<?xml version="1.0" encoding="utf-8"?><selector xmlns:android="http://schemas.android.com/apk/res/android">    <item android:drawable="@drawable/btn_shape" android:state_pressed="false"/>    <item android:drawable="@drawable/btn_shape_after" android:state_pressed="true"/></selector>
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三、编辑输入的信息正确然后跳转的布局文件：activity_main.xml

<?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="cn.edn.bzu.case_login.MainActivity">    <TextView        android:id="@+id/textView"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:text="Welcome you"        android:layout_alignParentTop="true"        android:layout_centerHorizontal="true"        android:textSize="40sp"/></RelativeLayout>
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四、在LoginActivity中进行相应的操作

package cn.edn.bzu.case_login;import android.content.Context;import android.content.Intent;import android.content.SharedPreferences;import android.support.v7.app.AppCompatActivity;import android.os.Bundle;import android.support.v7.widget.ShareActionProvider;import android.view.View;import android.widget.CheckBox;import android.widget.EditText;import android.widget.Toast;public class LoginActivity extends AppCompatActivity {    private EditText etName;    private EditText etPassword;    private CheckBox cbIsRememberPass;    private SharedPreferences sharedPreferences;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_login);        initViews();        sharedPreferences=getSharedPreferences("rememberpassword", Context.MODE_PRIVATE);        boolean isRemember= sharedPreferences.getBoolean("rememberpassword",false);        if(isRemember)        {            String name=sharedPreferences.getString("name","");            String password=sharedPreferences.getString("password","");            etName.setText(name);            etPassword.setText(password);            cbIsRememberPass.setChecked(true);        }    }    private void initViews()    {        etName= (EditText) findViewById(R.id.etName);        etPassword= (EditText) findViewById(R.id.etPassword);        cbIsRememberPass= (CheckBox) findViewById(R.id.cbIsRememberPass);    }    public void login(View view)    {        String name=etName.getText().toString();        String password=etPassword.getText().toString();        if("admin".equals(name)&&"123456".equals(password))        {            SharedPreferences.Editor editor=sharedPreferences.edit();            if(cbIsRememberPass.isChecked())            {                editor.putBoolean("rememberpassword",true);                editor.putString("name",name);                editor.putString("password",password);            }            else            {                editor.clear();            }            editor.commit();            Intent intent=new Intent(this,MainActivity.class);            startActivity(intent);            finish();        }else        {            Toast.makeText(this,"账号或密码有误",Toast.LENGTH_LONG).show();        }    }}

五、登录成功跳转到MainActivity

package cn.edn.bzu.case_login;import android.support.v7.app.AppCompatActivity;import android.os.Bundle;public class MainActivity extends AppCompatActivity {    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);    }}

六、打开虚拟机的Android Device Monitor