Question

youtube中有此视频https://www.youtube.com/watch?v=Idtm2Y6I23w 因此，该人具有动态填充的按钮，这些按钮是从存储在数据库中的项目创建的。例如在该图片中

它有一些类别包括Tables，Stock，Reports和Users 当用户单击Table类别时，它会显示从存储在数据库mysql中的项目动态创建的Buttons。例如，这是结果图像：

如何像这样发展？是否有一个将要使用的for循环语句？

编辑

这就是我做的。这是源代码。

public class OrderController implements Initializable {

    @FXML
    private ListView<Button> listvieww;

    @FXML
    private HBox hboxx;

    List<String> listOfSomething = null;
//@FXML
//    private Pane panedynamic;
    private DBConnection database = new DBConnection();
    private Connection connection;
    private Statement statement;
    private ResultSet resultSet;

    private ObservableList<Button> buttons = FXCollections.observableArrayList();

    /**
     * Initializes the controller class.
     */
    @Override
    public void initialize(URL url, ResourceBundle rb) {
    hboxx.getChildren().add(buttons)
    }

    @FXML
    void acttable(ActionEvent event) {

        // TODO
        String sqlQuery = "SELECT * FROM restauranttables;";
        try {
            connection = database.getConnection();
            statement = connection.createStatement();
            resultSet = statement.executeQuery(sqlQuery);
            while (resultSet.next()) {
                String current = resultSet.getString("tablename");
                ObservableList<String> list = FXCollections.observableArrayList(current);
                Button b = new Button(list.toString());
                buttons.add(b);

            }

        } catch (SQLException e) {
            e.printStackTrace();
        }

    }

    @FXML
    void actlogout(ActionEvent event) {

    }

    @FXML
    void actnew(ActionEvent event) {

    }

    @FXML
    void actorder(ActionEvent event) {

    }

    @FXML
    void actreports(ActionEvent event) {

    }

    @FXML
    void actstock(ActionEvent event) {

    }



    @FXML
    void actusers(ActionEvent event) {

    }

}

这就是我的场景构建器的样子

<?xml version="1.0" encoding="UTF-8"?>

<?import com.jfoenix.controls.JFXButton?>
<?import com.jfoenix.controls.JFXTextField?>
<?import javafx.scene.control.Menu?>
<?import javafx.scene.control.MenuBar?>
<?import javafx.scene.control.MenuItem?>
<?import javafx.scene.control.TableColumn?>
<?import javafx.scene.control.TableView?>
<?import javafx.scene.layout.AnchorPane?>
<?import javafx.scene.layout.ColumnConstraints?>
<?import javafx.scene.layout.GridPane?>
<?import javafx.scene.layout.HBox?>
<?import javafx.scene.layout.RowConstraints?>
<?import javafx.scene.layout.StackPane?>

<AnchorPane id="AnchorPane" prefHeight="600.0" prefWidth="1080.0" xmlns="http://javafx.com/javafx/8.0.111" xmlns:fx="http://javafx.com/fxml/1" fx:controller="controllers.OrderController">
    <children>
        <AnchorPane layoutX="55.0" layoutY="29.0" prefHeight="600.0" prefWidth="1080.0" AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="0.0" AnchorPane.topAnchor="0.0">
            <children>
                <TableView layoutX="21.0" layoutY="49.0" prefHeight="386.0" prefWidth="413.0">
                    <columns>
                        <TableColumn prefWidth="122.0" text="Description" />
                        <TableColumn prefWidth="57.0" text="Price" />
                        <TableColumn prefWidth="81.0" text="Sub Total" />
                        <TableColumn prefWidth="96.0" text="Table Id" />
                        <TableColumn prefWidth="57.0" text="Price" />
                    </columns>
                </TableView>
                <JFXTextField layoutX="53.0" layoutY="439.0" prefHeight="37.0" prefWidth="155.0" />
                <JFXTextField layoutX="253.0" layoutY="439.0" prefHeight="37.0" prefWidth="155.0" />
                <GridPane layoutX="63.0" layoutY="503.0" prefHeight="75.0" prefWidth="345.0">
                    <columnConstraints>
                        <ColumnConstraints hgrow="SOMETIMES" minWidth="10.0" prefWidth="100.0" />
                        <ColumnConstraints hgrow="SOMETIMES" minWidth="10.0" prefWidth="100.0" />
                    </columnConstraints>
                    <rowConstraints>
                        <RowConstraints minHeight="10.0" prefHeight="30.0" vgrow="SOMETIMES" />
                    </rowConstraints>
                    <children>
                        <AnchorPane prefHeight="200.0" prefWidth="200.0">
                            <children>
                                <JFXButton layoutX="25.0" layoutY="25.0" onAction="#actorder" prefHeight="75.0" prefWidth="173.0" text="Order" AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="0.0" AnchorPane.topAnchor="0.0" />
                            </children>
                        </AnchorPane>
                        <AnchorPane prefHeight="200.0" prefWidth="200.0" GridPane.columnIndex="1">
                            <children>
                                <JFXButton layoutX="39.0" layoutY="14.0" onAction="#actnew" prefHeight="75.0" prefWidth="172.0" text="New" AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="0.0" AnchorPane.topAnchor="0.0" />
                            </children>
                        </AnchorPane>
                    </children>
                </GridPane>
                <MenuBar layoutX="21.0" layoutY="14.0" prefHeight="29.0" prefWidth="413.0">
                    <menus>
                        <Menu mnemonicParsing="false" text="File">
                            <items>
                                <MenuItem mnemonicParsing="false" text="Close" />
                            </items>
                        </Menu>
                        <Menu mnemonicParsing="false" text="Edit">
                            <items>
                                <MenuItem mnemonicParsing="false" text="Delete" />
                            </items>
                        </Menu>
                        <Menu mnemonicParsing="false" text="Help">
                            <items>
                                <MenuItem mnemonicParsing="false" text="About" />
                            </items>
                        </Menu>
                    </menus>
                </MenuBar>
                <StackPane fx:id="acContent" layoutX="454.0" layoutY="49.0" prefHeight="525.0" prefWidth="605.0">
                    <children>
                        <AnchorPane fx:id="anchora" prefHeight="200.0" prefWidth="200.0">
                           <children>

                               <GridPane fx:id="sasa" layoutX="17.0" layoutY="7.0" prefHeight="90.0" prefWidth="571.0">
                                   <columnConstraints>
                                       <ColumnConstraints hgrow="SOMETIMES" minWidth="10.0" prefWidth="100.0" />
                                       <ColumnConstraints hgrow="SOMETIMES" minWidth="10.0" prefWidth="100.0" />
                                       <ColumnConstraints hgrow="SOMETIMES" minWidth="10.0" prefWidth="100.0" />
                                       <ColumnConstraints hgrow="SOMETIMES" minWidth="10.0" prefWidth="100.0" />
                                       <ColumnConstraints hgrow="SOMETIMES" minWidth="10.0" prefWidth="100.0" />
                                   </columnConstraints>
                                   <rowConstraints>
                                       <RowConstraints minHeight="10.0" prefHeight="30.0" vgrow="SOMETIMES" />
                                   </rowConstraints>
                                   <children>
                                       <AnchorPane prefHeight="200.0" prefWidth="200.0">
                                           <children>
                                               <JFXButton fx:id="table" layoutX="37.0" layoutY="19.0" onAction="#acttable" prefHeight="90.0" prefWidth="135.0" text="TABLE" AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="0.0" AnchorPane.topAnchor="0.0" />
                                           </children>
                                       </AnchorPane>
                                       <AnchorPane prefHeight="200.0" prefWidth="200.0" GridPane.columnIndex="1">
                                           <children>
                                               <JFXButton fx:id="stock" layoutX="43.0" layoutY="32.0" onAction="#actstock" prefHeight="90.0" prefWidth="134.0" text="STOCK" AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="0.0" AnchorPane.topAnchor="0.0" />
                                           </children>
                                       </AnchorPane>
                                       <AnchorPane prefHeight="200.0" prefWidth="200.0" GridPane.columnIndex="2">
                                           <children>
                                               <JFXButton fx:id="reports" layoutX="26.0" layoutY="32.0" onAction="#actreports" prefHeight="90.0" prefWidth="134.0" text="REPORTS" AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="0.0" AnchorPane.topAnchor="0.0" />
                                           </children>
                                       </AnchorPane>
                                       <AnchorPane prefHeight="200.0" prefWidth="200.0" GridPane.columnIndex="3">
                                           <children>
                                               <JFXButton fx:id="users" layoutX="26.0" layoutY="32.0" onAction="#actusers" prefHeight="90.0" prefWidth="134.0" text="USERS" AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="0.0" AnchorPane.topAnchor="0.0" />
                                           </children>
                                       </AnchorPane>
                                       <AnchorPane prefHeight="200.0" prefWidth="200.0" GridPane.columnIndex="4">
                                           <children>
                                               <JFXButton fx:id="logout" layoutX="28.0" layoutY="32.0" onAction="#actlogout" prefHeight="90.0" prefWidth="134.0" text="LOGOUT" AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="0.0" AnchorPane.topAnchor="0.0" />
                                           </children>
                                       </AnchorPane>
                                   </children>
                               </GridPane>
                        <HBox fx:id="hboxx" layoutX="17.0" layoutY="110.0" prefHeight="398.0" prefWidth="571.0" />
                           </children>
                        </AnchorPane>
                    </children>
                </StackPane>
            </children>
        </AnchorPane>
    </children>
</AnchorPane>

我想在hbox中对齐按钮，但在这里收到错误

@Override
    public void initialize(URL url, ResourceBundle rb) {
    hboxx.getChildren().add(buttons)
    }

任何帮助谢谢。

Answer 1

您要实施的工作流程：

根据动作事件从DB中检索一些信息
对于从（1）返回的每一行 - ＆gt;创建一个按钮

将所有创建的按钮添加到某个容器

@FXML
void acttable(ActionEvent event) {

String sqlQuery = "SELECT * FROM restauranttables;";
List<Button> buttonlist = new ArrayList<>(); //our Collection to hold newly created Buttons
try {
    connection = database.getConnection();
    statement = connection.createStatement();
    resultSet = statement.executeQuery(sqlQuery);
    while (resultSet.next()) { //iterate over every row returned
        String restaurant = resultSet.getString("restaurantname"); //extract button text, adapt the String to the columnname that you are interested in
        buttonlist.add(new Button(restaurant));

    }
    hboxx.getChildren().clear(); //remove all Buttons that are currently in the container
    hboxx.getChildren().addAll(buttonlist); //then add all your Buttons that you just created

} catch (SQLException e) {
    e.printStackTrace();
} finally{
    resultSet.close();
    statement.close();
    connection.close;
}
}

因此，作为工作流程，会发生什么：

您创建一个将包含所有新按钮的列表。
执行查询
从2
您获取要设置为Button Text
您将该按钮添加到列表
您从以前添加的按钮中清除您的HBox
您将所有新按钮添加到HBox

编辑：不要忘记关闭ResultSet，Statement和Connection。如果要将try / catch切换为try with resources，则可以避免显式.close（），因为所有三个对象都实现了Autoclosable接口。我添加了一个“finally”语句，将在try块退出时执行。您还可以检查resultSet / statement / connection是否为空。

Answer 2

你需要一个循环。基本上，您可以循环浏览项目，并为每个项目创建一个按钮并将其添加到窗格中。

List<Element> databaseItems = getElementFromDataBase(); 
int i = 0;
int j = 0;
for(Element databaseItem : databaseItems) {
    Button tempButton = new Button(databaseItem.getName());
    tempButton.setOnAction(new MyClickListener()) //handle button click
    gridPane.add(i, j);
    i ++;
    if(i == GridPane.getRowIndex()) {
        j++; // get to the new row.
    }
}

这段代码可能不准确，但它提供了一般性的想法。

Answer 3

// connectivity for mysql database coding
String category_name= "Stock";
 
Class.forName("com.mysql.jdbc.Driver");
Connection con=DriverManager.getConnection("jdbc:mysql://localhost:3306/sonoo","root","root");  
Statement stmt=con.createStatement();  
ResultSet rs=stmt.executeQuery("select * from category where category_name=" + "'" + category_name + "'");  
rs.next();


int num_of_rows = rs.getInt(3); (Fetched from database according to category)

Panel p1=new Panel();
p1.setLayout(new GridLayout(Math.Ceil(num_of_rows/6),6,10,10));

Button b[];

b=new Button[num_of_rows];

for(int i=0;i<num_of_rows;i++)
{
	b[i]=new Button(category_name + "" + (i+1));
	p1.add(b[i]);
	b[i].addActionListener(this); // needed if to perform button click
}

//adding the panel to the container
add(p1);


public void actionPerformed(ActionEvent ae)
{
	// The event click code goes here
}

JavaFX如何添加元素，例如。从存储在数据库Mysql中的项动态创建的按钮？

3 个答案: