Question

我想让我的代码检查我的表单中的文本字段是否为空＆amp;然后显示弹出警报消息。我的问题是，即使文本字段填写在这个警报消息中，一旦我点击“ENTER”就会弹出。任何帮助表示赞赏！

  BtnEnter.setOnAction((ActionEvent e) -> {


        if  (txtfName.getText().isEmpty() | txtlName.getText().isEmpty() | 
                txtMI.getText().isEmpty() | txtStreeAdd.getText().isEmpty()
                | txtCity.getText().isEmpty() | txtZip.getText().isEmpty()
                | txtPhone.getText().isEmpty() | txtEmail.getText().isEmpty()
                | txtSecEmail.getText().isEmpty()) {



            Alert alert = new Alert(Alert.AlertType.WARNING);
            alert.setTitle("Warning");
            alert.setHeaderText("Required Fields Empty");
            alert.setContentText("The fields highlighted in red must be filled "
                    + "out.\nPlease try again.");
            alert.showAndWait();

Answer 1

我认为部分问题可能是使用单个管道|代替标准||。

然而，您可以采取另一种方法，可能更容易阅读。这就是我在应用程序中处理验证的方法：

public boolean validate() {

        StringBuilder errors = new StringBuilder();

        // Confirm mandatory fields are filled out
        if (txtfName.getText().trim().isEmpty()) {
            errors.append("- Please enter a first name.\n");
        }
        if (txtlName.getText().trim().isEmpty()) {
            errors.append("- Please enter a last name.\n");
        }
        if (txtMI.getText().trim().isEmpty()) {
            errors.append("- Please enter a middle initial.\n");
        }
        if (txtStreetAdd.getText().trim().isEmpty()) {
            errors.append("- Please enter a street address.\n");
        }
        if (txtCity.getText().trim().isEmpty()) {
            errors.append("- Please enter a city.\n");
        }
        if (txtZip.getText().trim().isEmpty()) {
            errors.append("- Please enter a ZIP code.\n");
        }
        if (txtPhone.getText().trim().isEmpty()) {
            errors.append("- Please enter a phone number.\n");
        }
        if (txtEmail.getText().trim().isEmpty()) {
            errors.append("- Please enter a primary email address.\n");
        }
        if (txtSecEmail.getText().trim().isEmpty()) {
            errors.append("- Please enter a secondary email address.\n");
        }

        // If any missing information is found, show the error messages and return false
        if (errors.length() > 0) {
            Alert alert = new Alert(Alert.AlertType.WARNING);
            alert.setTitle("Warning");
            alert.setHeaderText("Required Fields Empty");
            alert.setContentText(errors.toString());

            alert.showAndWait();
            return false;
        }

        // No errors
        return true;
    }

这样做的另一个好处是让用户确切地知道缺少哪些信息。这样，您只需在用户单击操作按钮时调用validate()方法。如果validate()恢复正常，您就知道您拥有所需的所有信息。

Answer 2

您也可以通过另一种方式来处理它，而无需Alert Alert = new Alert（Alert.AlertType.WARNING）;这是一段代码：

public boolean validateForm() {

    StringBuilder errors = new StringBuilder();

    // Confirm mandatory fields are filled out
    if (jTextField1.getText().trim().isEmpty()) {
        errors.append("- Please enter a first name.\n");
        jTextField1.requestFocusInWindow();
        JOptionPane.showMessageDialog(null, errors, "Warning!", JOptionPane.ERROR_MESSAGE);
        return false;
    }
     if (jTextField2.getText().trim().isEmpty()) {
        errors.append("- Please enter a last name.\n");
        jTextField2.requestFocusInWindow();
        JOptionPane.showMessageDialog(null, errors, "Warning!", JOptionPane.ERROR_MESSAGE);
        return false;
    }
     String s = ((JTextField)jDateChooser1.getDateEditor().getUiComponent()).getText();
   if (s.equals("")) {
    errors.append("- Please choose a date.\n");
    jDateChooser1.requestFocusInWindow();
JOptionPane.showMessageDialog(null, errors, "Warning!", JOptionPane.ERROR_MESSAGE);
return false;

}

   if (jTextField3.getText().trim().isEmpty()) {
        errors.append("- Please enter the age.\n");
        jTextField3.requestFocusInWindow();
        JOptionPane.showMessageDialog(null, errors, "Warning!", JOptionPane.ERROR_MESSAGE);
        return false;
    }




return true;

}

通过这种方式，您可以检查用户是否知道确切缺少的内容，并向他们显示警告消息。为按钮添加一个侦听器。

private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {                                         
   if(validateForm()) {
      System.out.println("First name: "+jTextField1.getText());
      System.out.println("Last name: "+jTextField2.getText());
      System.out.println("Date: "+jDateChooser1.getDate());
       System.out.println("Age: "+jTextField3.getText());
   }
}

TextField为空时的警报消息（javafx）

2 个答案: