java怎么去JTF边框,关于java：我怎样才能摆脱“静态”？

本问题已经有最佳答案&＃xff0c;请猛点这里访问。

这是我的代码&＃xff1a;

public class Main extends JFrame{

static int NoOfUsers;

static String[][] Accounts &＃61; new String[NoOfUsers][2];

public static void main(String[] args){

Login();

}

private static void Login() {

final String FileName &＃61;"F:/TextFiles/loginaccs.txt";

try {

BufferedReader file &＃61; new BufferedReader(new InputStreamReader(new FileInputStream(FileName)));

int NoOfUsersL &＃61; Integer.parseInt(file.readLine());

String[][] Accounts &＃61; new String[NoOfUsersL][2];

NoOfUsers &＃61; NoOfUsersL;

for (int i&＃61;0; i

Accounts[i][0] &＃61; file.readLine();

Accounts[i][1] &＃61; file.readLine();

}

for (int i&＃61;0; i

System.out.println(Accounts[i][0]);

System.out.println(Accounts[i][1]);

}

file.close();

} catch (IOException e) {

System.out.println("ERROR: unable to read file.");

e.printStackTrace();

}

String username &＃61; null;

String password &＃61; null;

JTextField usernamejtf &＃61; new JTextField(username);

JPasswordField passwordjtf &＃61; new JPasswordField(password);

String[] buttons &＃61; {"Login","Create new account"};

Object[] InputDialog &＃61; {

"Username:", usernamejtf,"Password:", passwordjtf

};

do {

int option &＃61; JOptionPane.showOptionDialog(null,

InputDialog,

"Login",

JOptionPane.DEFAULT_OPTION,

JOptionPane.PLAIN_MESSAGE,

null,

buttons,

buttons[0]);

System.out.println(option); //Check

if (option &＃61;&＃61; JOptionPane.CLOSED_OPTION ) {

return;

}

else if (option &＃61;&＃61; 0) {

if (CheckAccount(username,password)) {

System.out.println("Logged in");

} else {

System.out.println("Wrong Password/Username");

}

} else if (option &＃61;&＃61; 1) {

System.out.println("Create Account.");

}

} while (!(CheckAccount(username,password)));

}

private static boolean CheckAccount(String username, String password) {

for (int i&＃61;0; i>NoOfUsers; i&＃43;&＃43;) {

if ((username &＃61;&＃61; Accounts[i][0]) && (password &＃61;&＃61; Accounts[i][1])) {

return true;

}

}

return false;

}

}

在"main"中&＃xff0c;我调用了login()方法&＃xff0c;Eclipse强迫我将单词"static"放在方法名前面。我是否可以修改程序&＃xff0c;使行可以写为&＃xff1a;private void login()…私有布尔支票帐户(…)…等&＃xff1f;

[附加问题&＃xff1a;因为"static"这个词&＃xff0c;我不能把"public"这个词放在string[]accounts&＃61;new string[noolfusersl][2]之前&＃xff1b;这使得checkaccount无法访问accounts数组。如何修改程序以解决此问题。]提前通知大家。

您必须创建一个EDOCX1的实例(0)&＃xff0c;以便将方法用作实例方法。

它强迫您使用static&＃xff0c;因为非静态方法属于instance&＃xff0c;而不是class。您必须创建一个Main的实例。

回答额外的问题&＃xff1a;可以。静态变量也被称为类变量。局部变量不能声明为静态。

静态方法静态方法是呼叫(不知道安安审审法)的呼叫建立和呼叫从第一页第一类为as belowP&＃xff1e;&＃xff1c;&＃xff0f;

public static void main(String[] args){

Main main &＃61; new Main();

main.login();

}

private void login() { //remove static from instance methods

哇&＃xff0c;不知道这么简单&＃xff0c;太多了。

为什么要将主实例存储在变量中&＃xff1f;你浪费了记忆。

&＃64;b&lint内存与new Main()一起使用。把它保存在变量中并不像你说的那样重要。这个变量只是对它的引用。

&＃64;很抱歉&＃xff0c;不客气。不要忘记调用setVisible方法来显示jframe&＃xff0c;还需要使用setBounds来设置帧的大小和位置。

在静态qualifiers阶to remove方法&＃xff0c;你必须让你的布尔变量的方法和实例变量。然后&＃xff0c;你可以和你的呼叫login()JFrame对象实例化。P&＃xff1e;&＃xff1c;&＃xff0f;

转换的方法也mixedcase /变量名称As to Java offical公约。恩&＃xff0c;你把我# VB或C语言编程&＃xff1f;P&＃xff1e;&＃xff1c;&＃xff0f;

import java.io.BufferedReader;

import java.io.FileInputStream;

import java.io.IOException;

import java.io.InputStreamReader;

import javax.swing.JFrame;

import javax.swing.JOptionPane;

import javax.swing.JPasswordField;

import javax.swing.JTextField;

import javax.swing.SwingUtilities;

public class Main extends JFrame {

private static final long serialVersionUID &＃61; -105943237549003486L;

private int numOfUsers;

private String[][] accounts;

public static void main(String[] args) {

SwingUtilities.invokeLater(new Runnable() {

&＃64;Override

public void run() {

Main m &＃61; new Main();

m.login("F:/TextFiles/loginaccs.txt");

}

});

}

// Constructor, set up instance values here.

public Main() {

super();

}

private void login(final String fileName) {

try {

BufferedReader file &＃61; new BufferedReader(new InputStreamReader(new FileInputStream(fileName)));

numOfUsers &＃61; Integer.parseInt(file.readLine());

accounts &＃61; new String[numOfUsers][2];

for (int i &＃61; 0; i

accounts[i][0] &＃61; file.readLine();

accounts[i][1] &＃61; file.readLine();

}

for (int i &＃61; 0; i

System.out.println(accounts[i][0]);

System.out.println(accounts[i][1]);

}

file.close();

} catch (IOException e) {

System.out.println("ERROR: unable to read file.");

e.printStackTrace();

}

String username &＃61; null;

String password &＃61; null;

JTextField usernamejtf &＃61; new JTextField(username);

JPasswordField passwordjtf &＃61; new JPasswordField(password);

String[] buttons &＃61; {"Login","Create new account" };

Object[] InputDialog &＃61; {"Username:", usernamejtf,"Password:", passwordjtf };

do {

int option &＃61; JOptionPane.showOptionDialog(null, InputDialog,"Login", JOptionPane.DEFAULT_OPTION,

JOptionPane.PLAIN_MESSAGE, null, buttons, buttons[0]);

System.out.println(option); // Check

if (option &＃61;&＃61; JOptionPane.CLOSED_OPTION) {

return;

} else if (option &＃61;&＃61; 0) {

if (checkAccount(username, password)) {

System.out.println("Logged in");

} else {

System.out.println("Wrong Password/Username");

}

} else if (option &＃61;&＃61; 1) {

System.out.println("Create Account.");

}

} while (!(checkAccount(username, password)));

}

private boolean checkAccount(String username, String password) {

for (int i &＃61; 0; i > numOfUsers; i&＃43;&＃43;) {

if (username &＃61;&＃61; accounts[i][0] && password &＃61;&＃61; accounts[i][1]) {

return true;

}

}

return false;

}

}

使用&＃xff1a;P&＃xff1e;&＃xff1c;&＃xff0f;

public static void main(String[] args){

Main main &＃61; new Main();

main.login();

}

为什么需要将实例存储在变量中&＃xff1f;你浪费了记忆。

&＃64;B&lint它无论如何都将存储在内存中&＃xff0c;因为它是在启动线程中执行的。

给new Main().login();P&＃xff1e;&＃xff1c;&＃xff0f;

You should naming约定后续变量和Java method should start&＃xff0c;lowercase名称与字母。P&＃xff1e;&＃xff1c;&＃xff0f;