安卓简单登录与注册

首先是效果图

1.MainXML

<?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:id="@+id/activity_main"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:orientation="vertical"    tools:context="com.bawei.day1010.MainActivity">    <RelativeLayout        android:layout_width="match_parent"        android:layout_height="wrap_content">        <EditText            android:id="@+id/etName"            android:drawableLeft="@mipmap/ic_launcher"            android:hint="请输入用户名"            android:layout_width="match_parent"            android:layout_height="wrap_content"/>        <Button            android:id="@+id/butClearName"            android:layout_centerVertical="true"            android:background="@mipmap/ic_launcher"            android:layout_alignParentRight="true"            android:layout_width="30dp"            android:layout_height="30dp"/>    </RelativeLayout>    <RelativeLayout        android:layout_width="match_parent"        android:layout_height="wrap_content">        <EditText            android:id="@+id/etPwd"            android:drawableLeft="@mipmap/ic_launcher"            android:hint="密码"            android:inputType="textPassword"            android:layout_width="match_parent"            android:layout_height="wrap_content"/>        <CheckBox            android:layout_centerVertical="true"            android:layout_alignParentRight="true"            android:id="@+id/pwdShow"            android:button="@mipmap/ic_launcher"            android:layout_width="wrap_content"            android:layout_height="wrap_content"/>        <Button            android:id="@+id/butClearPwd"            android:layout_centerVertical="true"            android:background="@mipmap/ic_launcher"            android:layout_toLeftOf="@id/pwdShow"            android:layout_width="30dp"            android:layout_height="30dp"/>    </RelativeLayout>    <Button        android:id="@+id/butLog"        android:text="登录"        android:layout_gravity="center_horizontal"        android:layout_width="match_parent"        android:layout_height="wrap_content"/>    <RelativeLayout        android:layout_width="match_parent"        android:layout_height="wrap_content">        <Button            android:background="@drawable/nullstroke"            android:textColor="#f00"            android:id="@+id/butReg"            android:text="注册"            android:layout_alignParentLeft="true"            android:layout_width="wrap_content"            android:layout_height="wrap_content"/>        <Button            android:background="@drawable/nullstroke"            android:textColor="#f00"            android:id="@+id/butForgetPwd"            android:text="忘记密码"            android:layout_alignParentRight="true"            android:layout_width="wrap_content"            android:layout_height="wrap_content"/>    </RelativeLayout></LinearLayout>

2.空Shape

<?xml version="1.0" encoding="utf-8"?><shape xmlns:android="http://schemas.android.com/apk/res/android"></shape>

3.Helper

public class MyHelper extends SQLiteOpenHelper {    public MyHelper(Context context) {        super(context, "mydb", null, 1);    }    @Override    public void onCreate(SQLiteDatabase db) {        db.execSQL("create table mytb(id integer primary key autoincrement,name text,pwd text)");    }    @Override    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {        db.execSQL("drop table if exists mydb");        onCreate(db);    }}

4.MainActivity

public class MainActivity extends AppCompatActivity implements View.OnClickListener {    private static final String TABLE = "mytb";    /**     * 请输入用户名     */    private EditText mEtName;    /**     * 密码     */    private EditText mEtPwd;    private CheckBox mPwdShow;    private Button mButClearName;    private Button mButClearPwd;    /**     * 登录     */    private Button mButLog;    /**     * 注册     */    private Button mButReg;    /**     * 忘记密码     */    private Button mButForgetPwd;    private SQLiteDatabase db;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        initView();        db = new MyHelper(this).getWritableDatabase();    }    private void initView() {        mEtName = (EditText) findViewById(R.id.etName);        mEtPwd = (EditText) findViewById(R.id.etPwd);        mPwdShow = (CheckBox) findViewById(R.id.pwdShow);        mPwdShow.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {            @Override            public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {                if (isChecked) {                    //选择状态 显示明文--设置为可见的密码                    mEtPwd.setInputType(InputType.TYPE_TEXT_VARIATION_VISIBLE_PASSWORD);                } else {                    //默认状态显示密码--设置文本 要一起写才能起作用 InputType.TYPE_CLASS_TEXT | InputType.TYPE_TEXT_VARIATION_PASSWORD                    mEtPwd.setInputType(InputType.TYPE_CLASS_TEXT | InputType.TYPE_TEXT_VARIATION_PASSWORD);                }            }        });        mButClearName = (Button) findViewById(R.id.butClearName);        mButClearName.setOnClickListener(this);        mButClearPwd = (Button) findViewById(R.id.butClearPwd);        mButClearPwd.setOnClickListener(this);        mButLog = (Button) findViewById(R.id.butLog);        mButLog.setOnClickListener(this);        mButReg = (Button) findViewById(R.id.butReg);        mButReg.setOnClickListener(this);        mButForgetPwd = (Button) findViewById(R.id.butForgetPwd);        mButForgetPwd.setOnClickListener(this);    }    @Override    public void onClick(View v) {        switch (v.getId()) {            case R.id.butClearName:                mEtName.setText("");                break;            case R.id.butClearPwd:                mEtPwd.setText("");                break;            case R.id.butLog:                String edNameLog1 = getEdString(mEtName);                String edPwdLog1 = getEdString(mEtPwd);                if(edNameLog1==null){                    Toast.makeText(MainActivity.this,"请输入用户名",Toast.LENGTH_SHORT).show();                    return;                }                if(edPwdLog1==null){                    Toast.makeText(MainActivity.this,"请输入密码",Toast.LENGTH_SHORT).show();                    return;                }                String sql="select * from mytb where name=? and pwd=?";                Cursor cursor = db.rawQuery(sql,new String[]{edNameLog1+"",edPwdLog1+""});                if(!cursor.moveToNext()){                        Toast.makeText(MainActivity.this,"用户名或密码不匹配",Toast.LENGTH_SHORT).show();                }else{                    Toast.makeText(MainActivity.this,"登录成功",Toast.LENGTH_SHORT).show();                }                break;            case R.id.butReg:                String edNameReg = getEdString(mEtName);                String edPwdReg= getEdString(mEtPwd);                if(edNameReg==null){                    Toast.makeText(MainActivity.this,"请输入用户名",Toast.LENGTH_SHORT).show();                    return;                }                if(edPwdReg==null){                    Toast.makeText(MainActivity.this,"请输入密码",Toast.LENGTH_SHORT).show();                    return;                }                //保存到数据库                ContentValues values=new ContentValues();                values.put("name",edNameReg);                values.put("pwd",edPwdReg);                long insert = db.insert(TABLE, null, values);                if(insert>0){                    Toast.makeText(MainActivity.this,"注册成功,请登录",Toast.LENGTH_SHORT).show();                }                break;            case R.id.butForgetPwd:                break;        }    }    /**     * 得到editText的字符串     */    public String getEdString(EditText editText) {        String s = editText.getText().toString();        if (s != null && !s.equals("")) {            return s;        }        return null;    }}

提示:这里可以加入自动登录的,使用SharePreferences  ,先保存一个标识,然后通过改变标识.每次进去先获取标识.