layoutdemo.java

J2ME lwuit实现屏幕九宫图,功能十分强大

/*
 * Copyright ?2008 Sun Microsystems, Inc. All rights reserved.
 * Use is subject to license terms.
 *
 */
package com.sun.lwuit.uidemo;

import com.sun.lwuit.Button;
import com.sun.lwuit.Form;
import com.sun.lwuit.events.ActionEvent;
import com.sun.lwuit.events.ActionListener;
import com.sun.lwuit.layouts.BorderLayout;
import com.sun.lwuit.layouts.BoxLayout;
import com.sun.lwuit.layouts.FlowLayout;
import com.sun.lwuit.layouts.GridLayout;

/**
 *本例演示如何布局窗体控件
 */
public class LayoutDemo implements ActionListener {

    public Form form = new Form("LayoutDemo");
    private Button border;
    private Button boxY;
    private Button boxX;
    private Button flow;
    private Button grid;

    LayoutDemo(){
        
        form.setLayout(new BoxLayout(BoxLayout.Y_AXIS));

        //BorderLayout,就是把窗体布局分成东、南、西、北、中这5部分
        border = new Button("BorderLayout");
        //顾名思义，设置按钮背景的透明度,范围0~255，可以用Util的资源编辑器来预先修改
        border.getStyle().setBgTransparency(100);
        //每个button都需要设计监听事件
        border.addActionListener(this);

        //BoxLayout-Y，就是把控件从上往下排列
        boxY = new Button("BoxLayout-Y");
        boxY.getStyle().setBgTransparency(100);
        boxY.addActionListener(this);

        //BoxLayout-X，就是把控件从左往右排列
        boxX = new Button("BoxLayout-X");
        boxX.getStyle().setBgTransparency(100);
        boxX.addActionListener(this);

        //FlowLayout，就是把控件按行排列，一行装不下则放到第二行......
        flow = new Button("FlowLayout");
        flow.getStyle().setBgTransparency(100);
        flow.addActionListener(this);

        //GridLayout,这就是实现九宫图的排列方式！！！！！
        grid = new Button("GridLayout");
        grid.getStyle().setBgTransparency(100);
        grid.addActionListener(this);
        
        addComponents(form);
        form.show();
    }
    private void addComponents(final Form f){
        f.removeAll();
        f.addComponent(boxY);
        f.addComponent(boxX);
        f.addComponent(border);
        f.addComponent(flow);
        f.addComponent(grid);
    }

    public void actionPerformed(ActionEvent arg0) {
        String button_name=((Button)(arg0.getSource())).getText();
        if(button_name.equals("BorderLayout"))
        {
            form.setLayout(new BorderLayout());
            form.removeAll();
            form.setScrollable(false);
            form.addComponent(BorderLayout.NORTH, border);
            form.addComponent(BorderLayout.EAST, boxY);
            form.addComponent(BorderLayout.CENTER, grid);
            form.addComponent(BorderLayout.WEST, flow);
            form.addComponent(BorderLayout.SOUTH, boxX);
            form.show();
        }
        else if(button_name.equals("BoxLayout-Y"))
        {
            form.setLayout(new BoxLayout(BoxLayout.Y_AXIS));
            form.setScrollable(false);
            addComponents(form);
            form.show();
        }
        else if(button_name.equals("FlowLayout"))
        {
            form.setLayout(new FlowLayout());
            form.setScrollable(false);
            addComponents(form);
            form.show();
        }
        else if(button_name.equals("GridLayout"))
        {
            form.setLayout(new GridLayout(3, 2));
            form.setScrollable(false);
            addComponents(form);
            form.show();
        }
        else if(button_name.equals("BoxLayout-X"))
        {
            form.setLayout(new BoxLayout(BoxLayout.X_AXIS));
            form.setScrollable(true);
            addComponents(form);
            form.show();
        }
    }
}