从另一个类禁用JButton

Question

我试图在同时使用Input Verifier时禁用按钮。 我想在文本字段为空时禁用按钮。 这是我的方法。

AddEmployee.class

public class AddEmployee extends javax.swing.JInternalFrame
{
    public JButton getJButton()
    {
        return addEmployeeButton;
    }

    public void setJButton(JButton buttonObject)
    {
        buttonObject = addEmployeeButton;
    }
}

ValidateComponents.class

public class ValidateComponents extends InputVerifier
{
   public void disable(JButton name)
   {
       AddEmployee employee = new AddEmployee();
       employee.setJButton(name);
       name.setEnabled(false);
   }

@Override
public boolean verify(JComponent input) 
{
    String tf = null;
    String ta = null;
    String name = input.getName(); //GETTING THE NAME OF THE COMPONENT
    if(input instanceof JTextField)
    {
        tf = ((JTextField) input).getText();

        if(name.equals("tfLastName") || name.equals("tfFirstName") || name.equals("tfMiddleName") || name.equals("tfNickname") || name.equals("tfGuardianContactName"))
        {
            if(tf.trim().length() == 0 || tf.equals(""))
            {
                input.setBackground(Color.PINK);//Set background color to pink if false.
                input.setToolTipText("Fields cannot left blank");
                return false;//Return false if the component need to keep focus
            }
       }
   }
}

在if条件下调用disable()方法是否有效？ 因此，如果文本字段为空，它可以调用。 任何帮助，将不胜感激！ 谢谢 ：）

更新：

public class ValidateComponents extends InputVerifier
{
      private AddEmployee employee = new AddEmployee();
      JButton myButton;
      public void disable(JButton name, boolean disable)
      {
        employee.setJButton(name);
        name.setEnabled(!disable);
        myButton = name;
      }

@Override
public boolean verify(JComponent input) 
{
    String tf = null;

    String name = input.getName(); //GETTING THE NAME OF THE COMPONENT
    if(input instanceof JTextField)
    {
        tf = ((JTextField) input).getText();

        if(name.equals("tfLastName") || name.equals("tfFirstName") || name.equals("tfMiddleName") || name.equals("tfNickname") || name.equals("tfGuardianContactName"))
        {
            boolean valid = tf.trim().length() > 0;

            disable(myButton, !valid);
            if(!valid)
            {
                input.setBackground(Color.PINK);//Set background color to pink if false.
                input.setToolTipText("Fields cannot left blank");
                return false;//Return false if the component need to keep focus
            }
}
}
}

Answer 1

您的班级应该稍作修改以更加灵活

private AddEmployee employee = new AddEmployee();

public void disable(JButton name, boolean disable){
    employee.setJButton(name);
    name.setEnabled(!disable); //NOT because yours is called disable and Swing's is called enabled ;)
}

由此，您可以轻松更改按钮的状态。 问题是，为什么需要将此添加到AddEmployee ？ 使用验证程序创建一个布尔值（每个示例有效），该布尔值将告诉您是否应该启用按钮。 如果您不这样做，则永远不会重新激活该按钮。

if(name.equals("tfLastName") || name.equals("tfFirstName") || name.equals("tfMiddleName") || name.equals("tfNickname") || name.equals("tfGuardianContactName"))
        {
            boolean valid = tf.trim().length() > 0; //Change the sign here and no need for the following > || tf.equals("")
            disable(myButton, !valid); // YOU NEED TO HAVE THE BUTTON INSTANCE SOMEWHERE, IN THE CONSTRUCTOR OR A SETTER...
            if(!valid){
                input.setBackground(Color.PINK);//Set background color to pink if false.
                input.setToolTipText("Fields cannot left blank");
                return false;//Return false if the component need to keep focus
            } else {
                // ADD THE VALID CASE HERE
            }
       }

仅需注意，您应该将要检查的实例发送到验证程序并将其存储在Collection中，然后作为input ，检查集合中是否有相同的实例（例如List），这比检查要干净名字 ;）

public class ValidateComponents extends InputVerifier
{
    JButton myButton;

    public ValidateComponents(JButton button)
        this.myButton = button;
    }

    ...

}

创建ValidateComponents实例时，只需设置按钮即可。