Android：注册登录

注册登录的实现

先在layout里新建一个xml文件：

//login.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="fill_parent"
    android:layout_height="fill_parent" >
    <TableLayout android:layout_width="fill_parent" android:layout_height="fill_parent" android:stretchColumns="1">
        <TableRow>
            <TextView android:text="用户名称：" android:id="@+id/TextView"
                android:layout_width="wrap_content" android:layout_height="wrap_content"></TextView>
            <EditText android:text="" android:id="@+id/userEditText"
                android:layout_width="fill_parent" android:layout_height="wrap_content"></EditText>
        </TableRow>
        <TableRow>
            <TextView android:text="用户密码：" android:id="@+id/TextView"
                android:layout_width="wrap_content" android:layout_height="wrap_content"></TextView>
            <EditText android:text="" android:id="@+id/pwdEditText"
                android:layout_width="fill_parent" android:layout_height="wrap_content"
                android:password="true"></EditText>
        </TableRow>
        <TableRow android:gravity="right">
            <Button android:text="取消" android:id="@+id/cancelButton"
                android:layout_width="wrap_content" android:layout_height="wrap_content"></Button>
            <Button android:text="登陆" android:id="@+id/loginButton"
                android:layout_width="wrap_content" android:layout_height="wrap_content"></Button>
        </TableRow>
    </TableLayout>
</LinearLayout>

然后在java代码里实现控件的功能：

public class AndroidWorld extends Activity {
    private Button cancelBtn,loginBtn;
    private EditText userEditText,pwdEditText;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.login);
        cancelBtn = (Button)findViewById(R.id.cancelButton);
        loginBtn = (Button)findViewById(R.id.loginButton);
        userEditText = (EditText)findViewById(R.id.userEditText);
        pwdEditText = (EditText)findViewById(R.id.pwdEditText);

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

        loginBtn.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {
                if(validate()){
                    if(login()){
                        Intent intent = new Intent(AndroidWorld.this,LoginSuccess.class);
                        startActivity(intent);
                    }else{
                        showDialog("用户名称或者密码错误，请重新输入！");
                    }
                }
            }
        });
    }

    private boolean login(){
        String username = userEditText.getText().toString();
        String pwd = pwdEditText.getText().toString();
        String result=query(username,pwd);
        if(result!=null&&result.equals("1")){
            return true;
        }else{
            return false;
        }
    }

    private boolean validate(){
        String username = userEditText.getText().toString();
        if(username.equals("")){
            showDialog("用户名称是必填项！");
            return false;
        }
        String pwd = pwdEditText.getText().toString();
        if(pwd.equals("")){
            showDialog("用户密码是必填项！");
            return false;
        }
        return true;
    }
    private void showDialog(String msg){
        AlertDialog.Builder builder = new AlertDialog.Builder(this);
        builder.setMessage(msg)
               .setCancelable(false)
               .setPositiveButton("确定", new DialogInterface.OnClickListener() {
                   public void onClick(DialogInterface dialog, int id) {
                   }
               });
        AlertDialog alert = builder.create();
        alert.show();
    }

    private String query(String username,String password){
        String queryString = "username="+username+"&password="+password;
        String url = HttpUtil.BASE_URL+"servlet/LoginServlet?"+queryString;
        return HttpUtil.queryStringForPost(url);
    }
}

参考资料链接：

代码下载链接： http://www.apkbus.com/android-139324-1-1.html
http://www.apkbus.com/android-139325-1-1.html
http://www.apkbus.com/android-139361-1-1.html
http://www.apkbus.com/android-139375-1-1.html