SWT中的布局之-----FormLayout(表格式布局)-阿里云开发者社区

表格式(FormLayout类) 表格式布局管理器,通过创建组件各个边的距离来布局组件,和GridLayout一样强大.

　　用GridLayout与FormLayout都可以实现相同的界面效果,但有时使用后者会更有效,而且不会像GridLayout因为容器大小变化而导致布局错位.

　　使用marignWidth,marginHeight设置边距(这两个属性,来设置容器的左边距和上边距(单位:像素))

　　使用FormData的构造函数(FormLayout也有自己的布局数据类,他的使用方法是new FormData()或new FormData(int width,int height))

　　FormAttachment类的用法

　　FormAttachment是在FormData下的,更进一步的布局数据类,它的用法主要体现在它不同的构造函数中.

FormLayout1.java

 1 import org.eclipse.swt.SWT;
 2 import org.eclipse.swt.layout.FormLayout;
 3 import org.eclipse.swt.widgets.Button;
 4 import org.eclipse.swt.widgets.Display;
 5 import org.eclipse.swt.widgets.Shell;
 6 
 7 public class FormLayout1 {
 8     public static void main(String[] args) {
 9         final Display display = Display.getDefault();
10         final Shell shell = new Shell();
11         shell.setSize(327, 253);
12         // ---------创建窗口中的其他界面组件-------------
13         FormLayout formLayout = new FormLayout();
14         formLayout.marginWidth = 100; // 左边距，单位：像素
15         formLayout.marginHeight = 50; // 上边距
16         shell.setLayout(formLayout);
17         new Button(shell, SWT.NONE).setText("button1");
18         // -----------------END------------------------
19         shell.layout();
20         shell.open();
21         while (!shell.isDisposed()) {
22             if (!display.readAndDispatch())
23                 display.sleep();
24         }
25         display.dispose();
26     }
27 }

1.使用marginWidth,marginHeight设置边距

这两个属性用来设置容器的左边距和上边距(单位:像素).下面给出一个具体的实例:

 1 public class FormLayout1 {
 2     public static void main(String[] args) {
 3         final Display display = Display.getDefault();
 4         final Shell shell = new Shell();
 5         shell.setSize(327, 253);
 6         shell.setText("SWT Application");
 7         // ------------------新插入的界面核心代码------------------------
 8         FormLayout formLayout = new FormLayout();
 9         formLayout.marginWidth = 100;
10         formLayout.marginHeight = 50;
11         shell.setLayout(formLayout);
12         new Button(shell, SWT.NONE).setText("button1");
13         // ------------------END---------------------------------------------
14         shell.layout();
15         shell.open();
16         while (!shell.isDisposed()) {
17             if (!display.readAndDispatch()) {
18                 display.sleep();
19             }
20         }
21     }
22 }

2.使用FormData的构造函数

FromLayout也有自己的布局数据类FormData,它的使用方法是:new FormData()或者new FormData(int width,int height)

 1 public class FormData1 {
 2     public static void main(String[] args) {
 3         final Display display = Display.getDefault();
 4         final Shell shell = new Shell();
 5         shell.setSize(327, 253);
 6         shell.setText("SWT Application");
 7         // ------------------新插入的界面核心代码------------------------
 8         shell.setLayout(new FormLayout());
 9         // new FormData ()
10         Button button1 = new Button(shell, SWT.NONE);
11         button1.setText("button1");
12         FormData formData = new FormData();
13         button1.setLayoutData(formData);
14         // new FormData (int width, int height)，单位：像素
15         Button button2 = new Button(shell, SWT.NONE);
16         button2.setText("button2");
17         FormData formData2 = new FormData(200, 50);// button2变成200长，50宽
18         button2.setLayoutData(formData2);
19         // ------------------END---------------------------------------------
20         shell.layout();
21         shell.open();
22         while (!shell.isDisposed()) {
23             if (!display.readAndDispatch()) {
24                 display.sleep();
25             }
26         }
27     }
28 }

3.FormAttachment类的用法:

FromAttachment是在FormData下的,更进一步的布局数据类.它的用法体现在他不同的构造函数中.

(1) new FormAttachment(int numerator,int offset)

　　button1的顶边(fromData.top)离shell容器的空白边距是shell容器总体空白长度的60%.

　　偏移的点数(points)为0,效果如下:

 1         //>>>>>>>>>>>>>>>华丽丽的分割线>>>>>>>>>>>>>>>>>>>>>>>>>>>>
 2         shell.setLayout(new FormLayout());
 3         new Text(shell, SWT.BORDER).setText("text1");
 4         //将button1应用FormData
 5         Button button1 = new Button(shell, SWT.NONE);
 6         button1.setText("button1");
 7         
 8         FormData formData = new FormData();
 9         formData.top = new FormAttachment(60, 0); // button1的顶端应用FormAttachment设置
10         button1.setLayoutData(formData);
11         
12         //>>>>>>>>>>>>>>>华丽丽的分割线>>>>>>>>>>>>>>>>>>>>>>>>>>>>

如果改成了 formData.top = new FormAttachment(60, 30)

从图中更以看出FormAttachment(60,30)是先按照FormAttachment(60,0)

的方式布局后,再下移动10个像素.这个地方有一个布局的次序.

new FormAttachment(int numerator)相当于new FormAttachment(int numerator,int offset)

当offset=0时,new FormAttachment(int numerator,int offset)相当于FormAttachmetn(int numerator,int denominator,int offset)当denominator(分母的意思)=100时,其中denominator是分母,例如FormAttachment(30,50,0)就是长度比例为30/50=60%,也就是和FormAttachment(60,0)的效果是一样的.

(2) new FormAttachment(Control control,int offset,int alignment)

　　参数1是一个Control类,一般在使用的时候,都传入一个组件(如文本框来做参数),应用此FormAttachment的组件将

　　依据参数1的contorl为基准来布局,offset为离control偏移量(单位:像素),alignment为对齐方式.

　　下面给出一个例子:

 1         //======================华丽丽的分割线===========================
 2         shell.setLayout(new FormLayout());
 3         Text text1 = new Text(shell, SWT.BORDER);
 4         text1.setLayoutData(new FormData(100, 50));
 5         //定义并设置FormData
 6         FormData formData = new FormData();
 7         //以text1为基准偏移50像素
 8         FormAttachment formAttachment = new FormAttachment(text1,50);
 9         formData.top = formAttachment;
10         formData.left = formAttachment;
11         // 将button1应用FormData
12         Button button1 = new Button(shell, SWT.NONE);
13         button1.setText("button1");
14         button1.setLayoutData(formData);
15         //======================华丽丽的分割线===========================

new FormAttachment(text1,50,int alignment)中alignment的设置的效果如图所示,

表中的效果的程序就是按照上面的代码为基础修改"FormAttachment formAttachment = new FormAttachment(text1,50);"

这一句得到的.

FormAttachment1.java

 1 public class FormAttachment1 {
 2     public static void main(String[] args) {
 3         final Display display = Display.getDefault();
 4         final Shell shell = new Shell();
 5         shell.setSize(327, 253);
 6         // ---------创建窗口中的其他界面组件-------------
 7         shell.setLayout(new FormLayout());
 8         Button button = new Button(shell, SWT.NONE);
 9         button.setText("button");
10         FormData formData = new FormData();
11         // 按钮的顶端（formData.top）离shell容器的空白边距是shell容器总体空白长度的60%
12         formData.top = new FormAttachment(60, 0);
13         button.setLayoutData(formData);
14         // -----------------END------------------------
15         shell.layout();
16         shell.open();
17         while (!shell.isDisposed()) {
18             if (!display.readAndDispatch())
19                 display.sleep();
20         }
21         display.dispose();
22     }
23 }

FormAttachment2.java

 1 public class FormAttachment2 {
 2     public static void main(String[] args) {
 3         final Display display = Display.getDefault();
 4         final Shell shell = new Shell();
 5         shell.setSize(327, 253);
 6         // ---------创建窗口中的其他界面组件-------------
 7         shell.setLayout(new FormLayout());
 8         Text text1 = new Text(shell, SWT.BORDER);
 9         text1.setLayoutData(new FormData(100, 50));
10         // 定义并设置FormData
11         FormData formData = new FormData();
12         // 以text1为基准偏移50像素
13         FormAttachment formAttachment = new FormAttachment(text1, 50);
14         // FormAttachment formAttachment = new FormAttachment(text1, 50,
15         // SWT.LEFT);参数3的可选值包括SWT.DEFAULT、SWT.LEFT、SWT.CENTER、SWT.RIGHT、SWT.TOP、SWT.BOTTOM
16         formData.top = formAttachment;
17         formData.left = formAttachment;
18         // 将button1应用FormData
19         Button button1 = new Button(shell, SWT.NONE);
20         button1.setText("button1");
21         button1.setLayoutData(formData);
22         // -----------------END------------------------
23         shell.layout();
24         shell.open();
25         while (!shell.isDisposed()) {
26             if (!display.readAndDispatch())
27                 display.sleep();
28         }
29         display.dispose();
30     }
31 }

本文转自SummerChill博客园博客，原文链接：http://www.cnblogs.com/DreamDrive/p/4171868.html，如需转载请自行联系原作者

SWT中的布局之-----FormLayout(表格式布局)

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