在 java netbeans 中调用方法

Question

I want to write clear button method in one class in another package. And i want to call that method in clear button as button click event.

Eg-

Package A class a <---- I want to write method in here.

Package B class b <---- in here i have that clear button i want to call that method here.

I'm facing some error in text fields!!!.

public boolean Clear(){
    boolean clearDate =false;
    Connection dbConn = null;

    StaffId_Text.setText("");
    First_Name_Text.setText("");
    Middle_Name_Text.setText("");
    Last_Name_Text.setText("");
    Civil_Status_Text.setText("");
    NIC_Text.setText("");
    Email_Text.setText("");
    Address_Text.setText("");
    Contact_Number_Text.setText("");

    return clearDate;
}

Answer 1

In order to use a variable inside a method this variable has to be "known" there. This can be done either be declare a variable like private String text or by passing the variable to method as an argument like b.Clear(textField) . That way the method Clear knows the variable textField and can work with it.

This is an example how this can be done:

public boolean clear(JTextField... textfields) { // method names should begin
    boolean clearDate = false;                   // with a lower case letter
    Connection dbConn = null;

    for (JTextField textField : textfields) {
        textField.setText("");
    }

    return clearDate;
}

Here I declare a method called clear which will take an amount of variables of type JTextField . Inside that method I iterate over every passed JTextField and call the method setText("") on it.

Now you can call your method like this:

public void clearEvent() {
    b.clear(staffIdText, firstNameText, middleNameText, [and so on...]);
}

You can pass as many JTextFields to this method as you like.

You can also use a list like I mentioned in the comment, but I guess this variant here is much more convenient.