如何从其他类中获取String的值到Android中的类？

Question

我的代码就像这样，创建了一个构造函数。我想从homepage.java访问该字符串到login.php。但android给了我一个错误“访问构造函数不允许”..我做错了吗？请帮助。 HomePage.java

public class HomePage extends Activity {

private Button clBtn;
private Button bcBtn;
private Button atBtn;
public String ip="";

 HomePage()
 {
    this.ip = "http://111.111.11.1/sp/";
 }

    public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.home_page);
    }
}

login.java

public class Login extends Activity {

private EditText etFacNo; 
private EditText etPassword;
private Button loginBtn;
HomePage getIP = new HomePage();
String url = getIP.ip;


public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.login_page);

    .
    .
    .
    .
    .
    HttpClient httpclient = new DefaultHttpClient();
    HttpPost request = new HttpPost(url+"loginteacher.php");

}
}

Answer 1

http://docs.oracle.com/javase/tutorial/java/javaOO/accesscontrol.html

您已使用 no modifier 声明了HomePage的构造函数。这意味着只有同一个包中的类可以调用它，这就是你收到错误的原因。

HomePage()
{
    ...

将其设为public

public HomePage()
{
    ...