LoginAvtivity如下:
主要是sharedpreference和文本框.getText对于各个界面的密码用户名的保存和使用，还有就是状态的保存，第一次注册过就不能再注册.
其中我发现在一个活动中使用TextView,****比如TextView tv=(TextView)findViewById(R.id.tv);中即使你将TextView tv设置成public TextView tv;
在其他活动中也无法使用，这是因为TextView是在onCreate()方法中定义的,局部变量设置public,private之类的都是无效的.此时只能依赖preference。
public class LoginActivity extends Activity implements OnClickListener{
private Button loginButton;
private Button registerButton;
public EditText username;
private EditText password;
// public SharedPreferences sp;
private String aString;
private String bString;
private SharedPreferences preferences;
private Editor editor;
private Boolean ab;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView(R.layout.activity_login);
preferences = getSharedPreferences("config", MODE_PRIVATE);
editor = preferences.edit();
loginButton = (Button) findViewById(R.id.btn_login);
registerButton = (Button) findViewById(R.id.btn_register);
username = (EditText) findViewById(R.id.username);
password = (EditText) findViewById(R.id.password);
loginButton.setOnClickListener(this);
registerButton.setOnClickListener(this);
ab = preferences.getBoolean("ok", false);
aString = preferences.getString("YY", "");
bString = preferences.getString("LL", "");
}
public void login(){
String aa=username.getText().toString();
String bb=password.getText().toString();
if (aa.equals(aString)&& bb.equals(bString)) {
Intent intent2=new Intent(LoginActivity.this,MainActivity.class);
startActivity(intent2);
}
else {
Intent intent = new Intent(LoginActivity.this,
AgainLoginActivity.class);
startActivity(intent);
}
}
public void register(){
if (ab) {
Toast.makeText(getApplicationContext(), "你已经注册过了", 0).show();
}else {
Intent intent = new Intent(LoginActivity.this,
RegisterActivity.class);
startActivity(intent);
editor.putBoolean("ok",true);
editor.commit();
finish();
}
}
@Override
public void onClick(View v) {
switch (v.getId()) {
case R.id.btn_login:
login();
break;
case R.id.btn_register:
register();
break;
default:
break;
}
}
}
register.java如下:
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView(R.layout.activity_register);
username = (EditText) findViewById(R.id.username);
password = (EditText) findViewById(R.id.password);
confirm_password = (EditText) findViewById(R.id.confirm_password);
registerButton = (Button) findViewById(R.id.btn_register);
registerButton.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View arg0) {
yonghuming=username.getText().toString();
mima=password.getText().toString();
querenmima=confirm_password.getText().toString();
sp=getSharedPreferences("config", MODE_PRIVATE);
Editor editor=sp.edit();
editor.putString("YY", yonghuming);
editor.putString("LL", mima);
editor.commit();
if (!TextUtils.isEmpty(yonghuming)) {
if (mima.equals(querenmima)) {
register();
}
else{
Toast.makeText(getApplicationContext(), "两次密码不一致", Toast.LENGTH_LONG).show(); }
}
else {
Toast.makeText(getApplicationContext(), "用户名为空", 0).show();
}
}
});
}
public void register() {
Intent intent = new Intent(RegisterActivity.this,AgainLoginActivity.class);
startActivity(intent);
finish();
}
}
AgainLoginAtivity.java如下:
public class AgainLoginActivity extends Activity implements OnClickListener{
private Button loginButton;
private Button registerButton;
public EditText username2;
public EditText password2;
public String mima2;
public String yonghuming2;
SharedPreferences sp;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView(R.layout.activity_login2_again);
username2 = (EditText) findViewById(R.id.username2);
password2 = (EditText) findViewById(R.id.password2);
loginButton = (Button) findViewById(R.id.btn_login);
loginButton.setOnClickListener(this);
}
public void login(){
mima2=password2.getText().toString();
yonghuming2=username2.getText().toString();
SharedPreferences preferences=getSharedPreferences(“config”, MODE_PRIVATE);
String name=preferences.getString(“YY”, “”);
String mimaa=preferences.getString(“LL”,”“);
if (yonghuming2.equals(name)) {
if (mima2.equals(mimaa)) {
Intent intent = new Intent(AgainLoginActivity.this,
MainActivity.class);
startActivity(intent);
finish();
}
else {
Toast.makeText(getApplicationContext(), "密码不同", Toast.LENGTH_SHORT).show();
}
}
else {
Toast.makeText(getApplicationContext(), "用户名不同", Toast.LENGTH_SHORT).show();
}
}
@Override
public void onClick(View v) {
switch (v.getId()) {
case R.id.btn_login:
login();
break;
default:
break;
}
}
}