我無法登錄到我的帳戶（陣列）在JavaFX

Question

所以我想創建一個程序，爲用戶創建一個新的帳戶，用戶應該能夠'登錄'與同一個帳戶。現在，我已經設法完成第一部分（使用數組創建帳戶），但現在我不知道如何使用該帳戶登錄。

PS：當我說的密碼，它只是彈出

下面的代碼的alertbox：

import javafx.application.Application; 
import javafx.event.ActionEvent; 
import javafx.event.EventHandler; 
import javafx.scene.Scene; 
import javafx.scene.control.Button; 
import javafx.scene.control.TextField; 
import javafx.scene.control.PasswordField ; 
import javafx.scene.control.Label; 
import javafx.scene.layout.VBox; 
import javafx.stage.Stage; 
public class LoginEN extends Application { 

    Button btnCreate,btnLogin; 
    TextField txtUsername; 
    PasswordField Password; 
    Label lblUsername,lblPassword; 
    int index=0; 
    String[] user = new String[11]; 
    String[] pas = new String[11]; 


    public static void main(String[] args) { 
     launch(args); 
    } 

    @Override 
    public void start(Stage primaryStage) { 
     primaryStage.setTitle("Create and login"); 


     btnCreate = new Button(); 
     btnCreate.setText("Create"); 

     btnLogin = new Button(); 
     btnLogin.setText("Login"); 

     txtUsername=new TextField(); 
     txtUsername.setMaxWidth(200); 

     Password=new PasswordField(); 
     Password.setMaxWidth(200); 

     lblUsername=new Label(); 
     lblUsername.setText("Username"); 

     lblPassword=new Label(); 
     lblPassword.setText("Pasword"); 

     btnCreate.setOnAction(e ->{ 
      if (index < 12){ 
      index++; 
      user[index]=txtUsername.getText(); 
      pas[index]=Password.getText(); 

      AlertBox.display("Account information","Your account has been succesfully created: \n Username: " + user[index] + " \n Pasword: " + pas[index] ); 
      txtUsername.clear(); 
      Password.clear(); 
     }else{ 
      AlertBox.display("Error", "You reached the limit."); 
     } 
     }); 
     btnLogin.setOnAction(e ->{ 
      for (int c = 0; c < 11; c++) 
      { 
       if ((txtUsername.equals(user[c])) && (Password.equals(user[c]))) { 
        AlertBox.display("OK", " Welcome to your account"); 
       } 
       break; 
     } 
     }); 
     VBox layout = new VBox(); 
     layout.getChildren().addAll(lblUsername,txtUsername,lblPassword,Password,btnCreate,btnLogin); 
     Scene scene = new Scene(layout, 300, 250); 
     primaryStage.setScene(scene); 
     primaryStage.show(); 
    } 


} 

編輯，但仍然無法正常工作：■...

import javafx.application.Application; 
import javafx.event.ActionEvent; 
import javafx.event.EventHandler; 
import javafx.scene.Scene; 
import javafx.scene.control.Button; 
import javafx.scene.control.TextField; 
import javafx.scene.control.PasswordField ; 
import javafx.scene.control.Label; 
import javafx.scene.layout.VBox; 
import javafx.stage.Stage; 
public class LoginEN extends Application { 

    Button btnCreate,btnLogin; 
    TextField txtUsername; 
    PasswordField Password; 
    Label lblUsername,lblPassword; 
    int index=0; 
    String[] user = new String[11]; 
    String[] pas = new String[11]; 


    public static void main(String[] args) { 
     launch(args); 
    } 

    @Override 
    public void start(Stage primaryStage) { 
     primaryStage.setTitle("Create and login"); 


     btnCreate = new Button(); 
     btnCreate.setText("Create"); 

     btnLogin = new Button(); 
     btnLogin.setText("Login"); 

     txtUsername=new TextField(); 
     txtUsername.setMaxWidth(200); 

     Password=new PasswordField(); 
     Password.setMaxWidth(200); 

     lblUsername=new Label(); 
     lblUsername.setText("Username"); 

     lblPassword=new Label(); 
     lblPassword.setText("Pasword"); 

     btnCreate.setOnAction(e ->{ 
      if (index < 11){ 
      user[index]=txtUsername.getText(); 
      pas[index]=Password.getText(); 

      AlertBox.display("Account information","Your account has been succesfully created: \n Username: " + user[index] + " \n Pasword: " + pas[index] ); 
      txtUsername.clear(); 
      Password.clear(); 
      index++; 
      }else{ 
      AlertBox.display("Error", "You reached the limit."); 
      } 
     }); 
     btnLogin.setOnAction(e ->{ 
      for (int c = 0; c < 11; c++) 
      { 
       if ((txtUsername.equals(user[c])) && (Password.equals(pas[c]))) { 
        AlertBox.display("OK", " Welcome to your account"); 
        break; 
       } 

     } 
     }); 
     VBox layout = new VBox(); 
     layout.getChildren().addAll(lblUsername,txtUsername,lblPassword,Password,btnCreate,btnLogin); 
     Scene scene = new Scene(layout, 300, 250); 
     primaryStage.setScene(scene); 
     primaryStage.show(); 
    } 


} 

Answer 1

在

if (index < 12){ 
    index++; 
    user[index]=txtUsername.getText(); 
    pas[index]=Password.getText(); 

    AlertBox.display("Account information","Your account has been succesfully created: \n Username: " + user[index] + " \n Pasword: " + pas[index] ); 
    txtUsername.clear(); 
    Password.clear(); 
} 

您的第一個帳戶在user[1]創建的，因爲你這樣做

user[index]=txtUsername.getText(); 
pas[index]=Password.getText(); 

因此，有犯規之前增加'指數」存在於user[0]的用戶，但在

for (int c = 0; c < 11; c++) 
{ 
    if ((txtUsername.equals(user[c])) && (Password.equals(user[c]))) { 
     AlertBox.display("OK", " Welcome to your account"); 
    } 
    break; 
} 

你開始檢查用戶在索引0處，並在if之後，您離開循環break;，因此您從不檢查索引1到10處的任何用戶。 還將txtUsername和Password與字符串中的字符串進行了比較，但是txtUsername和Password是inputfields，它永遠不會等於任何字符串。

另外，你的用戶和密碼陣列具有長度11，所以他們的最高指數爲10，但在

if (index < 12) 

您檢查指數低於12，並增加了，所以你使用的索引可以12，如果您創建的用戶超過10個，則會導致IndexOutOfBoundsException。

要分配後解決這個問題，增量指標，如果裏面的

user[index]=txtUsername.getText(); 
pas[index]=Password.getText(); 
index++; 

突破和比較文字，而不是域本身

if ((txtUsername.getText().equals(user[c])) && (Password.getText().equals(user[c]))) { 
    AlertBox.display("OK", " Welcome to your account"); 
    break; 
} 

並檢查指數低於11

if (index < 11) { 
    ... 
}