简单的员工记录 java 程序 GUI 删除按钮

Question

I have a program GUI that the user enters ID#, First Name, Last Name, Salary, Start Date. After the user enters this information into a text area for each information need, the users clicks the add button which stores the information into an arrayList. After clicking add, the user presses a "list" button to output all the information entered into a Panel.

Array list to store users data:

public class EmploymentRecords extends javax.swing.JFrame {

ArrayList <Data> Output = new ArrayList <Data>();

Remove Button code:

private void btnRemoveActionPerformed(java.awt.event.ActionEvent evt) {                                          
    
    int index;
    String id = txtID.getText();
    boolean idCheck = Output.contains(id);

    if (idCheck = true){
        index = Output.indexOf(id);
        Output.remove(index);
        lblError.setText("Employee found and has been removed.");
    }
    else {
        lblError.setText("Employee not found. Please try again.");
    }

class Data:

class Data {
    String id, firstName, lastName, salary, startDate;
    Data (String _id, String _firstName, String _lastName, String _salary, String _startDate) {
        id = _id;
        firstName = _firstName;
        lastName = _lastName;
        salary = _salary;
        startDate = _startDate;

Heres my problem: I want the user to be able to enter an id in the text area of the GUI where the program checks if that ID is entered before and totally removes all the data from the output screen and arraylist using just the ID. The code I entered above is not working for me and when I press the remove button nothing happens.

Please help as i would appreciate this... Thanks!

Answer 1

You are missing some code to share. But lets suppose your "add" functionality is working. Lets also suppose that "String id = txtID.getText();" will be able to get the id for you as a string. An obvious mistake is "if (idCheck = true)", as in java you compare with "==" So maybe you can try to fix it that way and report the answer.

Answer 2

What you have done works alright for single entity objects within an ArrayList (like ArrayList<String> or ArrayList<Integer> for example) but not so good for multi-entity objects like what you have in your Data class. In other words, each element within your ArrayList is holding an instance of a class and all members related to it, not just a simple String or an Integer.

You will need to go a wee bit deeper in order to actually acquire the ID of any particular Data object instance for comparison to what someone has supplied within a GUI, for example:

private void btnRemoveActionPerformed(java.awt.event.ActionEvent evt) {                                          
    String id = txtID.getText();

    boolean found = false;

    for (Data data : Output) {
        if (data.id.equals(id) {
           found = true;
           Output.remove(data);
           clearFieldsInForm();
           break;
        }
    }
    if (found) {
        lblError.setText("Employee was successfully removed.");
    }
    else {
        lblError.setText("Invalid ID! Employee not found! Please try again.");
    }
}

You will notice the clearFieldsInForm(); method use in the above code. This method would just set all pertinent form fields to Null String ("") which is essentially nothing:

private void clearFieldsInForm() {
    txtID.setText("");
    txtFirstName.setText("");
    txtLastName.setText("");
    txtsalary.setText("");
    txtStartDate.setText("");
}