Java AWT | SpringLayout 类
原文:https://www.geeksforgeeks.org/java-awt-springlayout-class/
AWT(抽象窗口工具包)中的一个 SpringLayout 类根据一组布局约束将子级布局到其关联的容器中。每个约束由一个弹簧对象表示，该对象控制两个组件边之间的垂直或水平距离。这些边可以属于容器的任何子级，也可以属于容器本身。默认情况下，弹簧布局创建约束，使其关联组件具有最小、首选、最大和实际值。
施工方:
- SpringLayout(): 用于构造一个新的 SpringLayout 类。
常用方法:
- void addLayoutComponent(Component com，Object cons): 如果约束是 SpringLayout 的一个实例。约束，将约束与指定的组件相关联。
- getLayoutAlignmentX(容器 c): 用于返回 0.5f(居中)。
- getLayoutAlignmentY(容器 c): 用于返回 0.5f(居中)。
- getConstraint((String edge name，Component c): 返回控制组件指定边缘与其父组件顶部或左侧边缘之间距离的弹簧。
- 获取约束(组件 c): 返回指定组件的约束。
- layoutContainer(容器父级):用于布局指定的容器。
下面的程序说明了 SpringLayout 类:
-
Program 1: Below program arranges the components in a JFrame. We create 1 JLabel components named “label” and create a 1 JTextField named “textfield” and create a 2 classes, one is JFrame class and another is SpringLayout class and then add them to the JFrame by the method add(). We set the visibility of the frame using setvisible() method. The layout is set by using setLayout() method.
```java // Java program to show Example of SpringLayout. // in java. Importing different Package. import java.awt.Container; import javax.swing.JFrame; import javax.swing.JLabel; import javax.swing.JTextField; import javax.swing.SpringLayout;
// construct a class springdemo public class Springdemo {
// It is used to create and show GUI private static void createAndShowGUI() {
// Creating Object of "JFrame" class JFrame frame = new JFrame("MySpringDemp");
// Function to set default // close operation of JFrame. frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
// to get content pane Container contentPane = frame.getContentPane();
// Creating Object of "Springlayout" class SpringLayout layout = new SpringLayout();
// to set content pane contentPane.setLayout(layout);
// Initialization of object // "label" of JLabel class. JLabel label = new JLabel("Label: ");
// Initialization of object // "label" of JLabel class. JTextField textField = new JTextField("Enter the text ", 15);
// to add content pane of JLabel contentPane.add(label);
// to add content pane of JTextField contentPane.add(textField);
// It is used to put the layout // constraint in JFrame using springLayout class layout.putConstraint(SpringLayout.WEST, label, 6, SpringLayout.WEST, contentPane);
layout.putConstraint(SpringLayout.NORTH, label, 6, SpringLayout.NORTH, contentPane);
layout.putConstraint(SpringLayout.WEST, textField, 6, SpringLayout.EAST, label);
layout.putConstraint(SpringLayout.NORTH, textField, 6, SpringLayout.NORTH, contentPane);
layout.putConstraint(SpringLayout.EAST, contentPane, 6, SpringLayout.EAST, textField);
layout.putConstraint(SpringLayout.SOUTH, contentPane, 6, SpringLayout.SOUTH, textField);
// Function to pack the JFrame. frame.pack();
// Function to set visible status of JFrame. frame.setVisible(true); }
// Main Method public static void main(String[] args) { javax.swing.SwingUtilities.invokeLater(new Runnable() {
// create a class public void run() { // to create and show GUI createAndShowGUI(); } }); } } ```
输出:
https://media.geeksforgeeks.org/wp-content/uploads/gfgspr1.mp4.mp4 * Program 2: Below program arranges the components in a JFrame. We create 1 class named “springlayout class” and create a 4 JButton components named “b1″, “b2”, “b3”, “b4”, “b5” and then add them to the JFrame by the method add(). We set the visibility of the frame by using the method setvisible(). The layout is set by setLayout() method.
```java // Java program to show Example of SpringLayout. // in java. Importing different Package. import java.awt.; import javax.swing.;
// construct a class Springclassdemo public class Springclassdemo {
// Main Method public static void main(String[] arguments) {
// main window // Function to set the default look // and feel decorated status of JFrame. JFrame.setDefaultLookAndFeelDecorated(true);
// Creating Object of "JFrame" class JFrame frame = new JFrame("SpringLayoutExample Example");
// Function to set the default // close operation status of JFrame frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
// Function to set the // size status of JFrame frame.setSize(300, 200);
// to get the content pane Container content = frame.getContentPane();
// Creating Object of "SpringLayout" class SpringLayout layout = new SpringLayout();
// to set the layout class frame.setLayout(layout);
// Initialization of object // "b1" of JButton class. Component b1 = new JButton("GEEKS");
// Initialization of object // "b2" of JButton class. Component b2 = new JButton("GFG");
// Initialization of object // "b3" of JButton class. Component b3 = new JButton("JAVA");
// Initialization of object // "b4" of JButton class. Component b4 = new JButton("Sudo Placement");
// Adding the JButton "b1" on frame frame.add(b1);
// Adding the JButton "b2" on frame frame.add(b2);
// Adding the JButton "b3" on frame frame.add(b3);
// Adding the JButton "b4" on frame frame.add(b4);
// It is used to put the layout // constraint in JFrame using // springLayout class on b1 JButton layout.putConstraint(SpringLayout.WEST, b1, 25, SpringLayout.WEST, content);
layout.putConstraint(SpringLayout.NORTH, b1, 10, SpringLayout.NORTH, content);
// It is used to put the layout // constraint in JFrame using // springLayout class on b2 JButton layout.putConstraint(SpringLayout.WEST, b2, 50, SpringLayout.WEST, content);
layout.putConstraint(SpringLayout.NORTH, b2, 10, SpringLayout.SOUTH, b1);
// It is used to put the layout // constraint in JFrame using // springLayout class on b3 JButton layout.putConstraint(SpringLayout.WEST, b3, 75, SpringLayout.WEST, content);
layout.putConstraint(SpringLayout.NORTH, b3, 10, SpringLayout.SOUTH, b2);
// It is used to put the layout // constraint in JFrame using // springLayout class on b4 JButton layout.putConstraint(SpringLayout.WEST, b4, 15, SpringLayout.EAST, b1);
layout.putConstraint(SpringLayout.NORTH, b4, 10, SpringLayout.NORTH, content);
// Function to set the // visible status of JFrame frame.setVisible(true); } } ```
输出:
https://media.geeksforgeeks.org/wp-content/uploads/gfgspring.mp4
注意:上述程序可能无法在在线 IDE 中运行。请使用离线编译器。
参考:https://docs . Oracle . com/javase/7/docs/API/javax/swing/springlayout . html
版权属于：月萌API www.moonapi.com，转载请注明出处
