介绍

FlowLayout类组件排列为左到右的流动。

类的声明

以下是声明的java.awt.FlowLayout类：

public class FlowLayout
   extends Object
      implements LayoutManager, Serializable

字段域

下面的java.awt.BorderLayout类的字段：

• static int CENTER -- 该值指示每一行组件都应该为中心。

• static int LEADING -- 此值指示每一行组件都应该是合理的容器的方向的前缘，例如，在左到右的方向的左侧。

• static int LEFT -- 此值表示每行组件都应该是左对齐。

• static int RIGHT -- 此值表示每行组件都应该是右对齐。

• static int TRAILING -- 此值指示每一行组件都应该是合理的容器的方向的后边缘，例如，在左到右的方向的右侧。

类的构造函数

S.N.	构造函数与说明
1	FlowLayout()  Constructs a new FlowLayout with a centered alignment and a default 5-unit horizontal and vertical gap.
2	FlowLayout(int align)  Constructs a new FlowLayout with the specified alignment and a default 5-unit horizontal and vertical gap.
3	FlowLayout(int align, int hgap, int vgap)  Creates a new flow layout manager with the indicated alignment and the indicated horizontal and vertical gaps.

类方法

S.N.	方法和说明
1	void addLayoutComponent(String name, Component comp)  Adds the specified component to the layout.
2	int getAlignment()  Gets the alignment for this layout.
3	int getHgap()  Gets the horizontal gap between components.
4	int getVgap()  Gets the vertical gap between components.
5	void layoutContainer(Container target)  Lays out the container.
6	Dimension minimumLayoutSize(Container target)  Returns the minimum dimensions needed to layout the visible components contained in the specified target container.
7	Dimension preferredLayoutSize(Container target)  Returns the preferred dimensions for this layout given the visible components in the specified target container.
8	void removeLayoutComponent(Component comp)  Removes the specified component from the layout.
9	void setAlignment(int align)  Sets the alignment for this layout.
10	void setHgap(int hgap)  Sets the horizontal gap between components.
11	void setVgap(int vgap)  Sets the vertical gap between components.
12	String toString()  Returns a string representation of this FlowLayout object and its values.

继承的方法

这个类继承的方法从以下类：

• java.lang.Object

FlowLayout 实例

选择使用任何编辑器创建以下java程序D:/ > AWT > com > yiibai > gui >

AwtLayoutDemo

package com.yiibai.gui;

import java.awt.*;
import java.awt.event.*;

public class AwtLayoutDemo {
   private Frame mainFrame;
   private Label headerLabel;
   private Label statusLabel;
   private Panel controlPanel;
   private Label msglabel;

   public AwtLayoutDemo(){
      prepareGUI();
   }

   public static void main(String[] args){
      AwtLayoutDemo  awtLayoutDemo = new AwtLayoutDemo();  
      awtLayoutDemo.showFlowLayoutDemo();       
   }
      
   private void prepareGUI(){
      mainFrame = new Frame("Java AWT Examples");
      mainFrame.setSize(400,400);
      mainFrame.setLayout(new GridLayout(3, 1));
      mainFrame.addWindowListener(new WindowAdapter() {
         public void windowClosing(WindowEvent windowEvent){
            System.exit(0);
         }        
      });    
      headerLabel = new Label();
      headerLabel.setAlignment(Label.CENTER);
      statusLabel = new Label();        
      statusLabel.setAlignment(Label.CENTER);
      statusLabel.setSize(350,100);

      msglabel = new Label();
      msglabel.setAlignment(Label.CENTER);
      msglabel.setText("Welcome to TutorialsPoint AWT Tutorial.");

      controlPanel = new Panel();
      controlPanel.setLayout(new FlowLayout());

      mainFrame.add(headerLabel);
      mainFrame.add(controlPanel);
      mainFrame.add(statusLabel);
      mainFrame.setVisible(true);  
   }

   private void showFlowLayoutDemo(){
      headerLabel.setText("Layout in action: FlowLayout");      

      Panel panel = new Panel();
      panel.setBackground(Color.darkGray);
      panel.setSize(200,200);
      FlowLayout layout = new FlowLayout();
      layout.setHgap(10);              
      layout.setVgap(10);
      panel.setLayout(layout);        
      panel.add(new Button("OK"));
      panel.add(new Button("Cancel"));       

      controlPanel.add(panel);

      mainFrame.setVisible(true);  
   }
}

编译程序，使用命令提示符。进入到D:/> AWT，然后键入以下命令。

D:AWT>javac comyiibaiguiAwtlayoutDemo.java

如果没有错误出现，这意味着编译成功。使用下面的命令来运行程序。

D:AWT>java com.yiibai.gui.AwtlayoutDemo

验证下面的输出