SWT应用之：随机RGB颜色、ScrolledComposite控件的使用（二）————SWT Component（SWT组件）使用

本文与文章《 SWT应用之：随机RGB颜色、ScrolledComposite控件的使用 》实现相同的效果和功能，只是实现的方式不同。

文章《 SWT应用之：随机RGB颜色、ScrolledComposite控件的使用 》是采用直接实现的方式，就是所有的功能和组件都在同一个类中，这样不能达到组件重用，在其他类中使

用又要实现相同的功能。本文采用SWT 组件的功能，对ScrolledComposite控件进行分离实现，使之成为一个公用组件，能够被其他类使用。

开始分步骤进行实现：

A：分离ScrolledComposite控件，新建一个类，继承ScrolledComposite控件类。实现ScrolledComposite类的构造方法。代码如下：

package com.swtcomponent;import java.io.File;import java.io.FileInputStream;import java.io.IOException;import org.eclipse.swt.SWT;import org.eclipse.swt.custom.ScrolledComposite;import org.eclipse.swt.events.SelectionAdapter;import org.eclipse.swt.events.SelectionEvent;import org.eclipse.swt.graphics.Color;import org.eclipse.swt.graphics.Image;import org.eclipse.swt.graphics.ImageData;import org.eclipse.swt.layout.GridData;import org.eclipse.swt.layout.GridLayout;import org.eclipse.swt.layout.grouplayout.GroupLayout;import org.eclipse.swt.layout.grouplayout.LayoutStyle;import org.eclipse.swt.widgets.Button;import org.eclipse.swt.widgets.Composite;import org.eclipse.swt.widgets.Display;import org.eclipse.swt.widgets.Group;import org.eclipse.swt.widgets.Label;import org.eclipse.swt.widgets.ScrollBar;public class SubScrollCompsite extends ScrolledComposite {private Composite composite;public Color color;public SubScrollCompsite(Composite parent, int count) {super(parent, SWT.BORDER | SWT.H_SCROLL | SWT.V_SCROLL);{showComposite(this,parent,count);}setContent(composite);setMinSize(composite.computeSize(SWT.DEFAULT, SWT.DEFAULT));}//设置ScrolledComposite相关属性private void setScrollBar(ScrolledComposite scrolledComposite){if (scrolledComposite != null) {ScrollBar vscrollBar = this.getVerticalBar();vscrollBar.setIncrement(100);super.setContent(composite);super.setExpandHorizontal(true);super.setExpandVertical(true);super.setMinSize(composite.computeSize(SWT.DEFAULT, SWT.DEFAULT));super.setFocus();}}//用于显示Composite里面的组件public void showComposite(ScrolledComposite scrolledComposite,Composite parent,int count) {if (scrolledComposite == null) {scrolledComposite = new ScrolledComposite(parent, SWT.BORDER | SWT.H_SCROLL | SWT.V_SCROLL);}composite = new Composite(scrolledComposite, SWT.NONE);GridLayout gridLayout = new GridLayout();gridLayout.numColumns = 5;composite.setLayout(gridLayout);{for (int i = 0; i < count; i++) {Group group_1 = new Group(composite, SWT.NONE);final Button button2 = new Button(group_1, SWT.NONE);Label label2 = new Label(group_1, SWT.NONE);group_1.setLayoutData(new GridData(SWT.CENTER, SWT.CENTER,true, true, 1, 1));{FileInputStream inputStream = null;try {inputStream = new FileInputStream(new File(".\\IMAGE\\a.jpg"));ImageData imageData = new ImageData(inputStream);button2.setImage(new Image(Display.getDefault(),imageData));color = new ProduceColor().produceColor();button2.setBackground(color);inputStream.close();} catch (IOException e) {e.printStackTrace();}button2.addSelectionListener(new SelectionAdapter() {@Overridepublic void widgetSelected(SelectionEvent e) {color = button2.getBackground();ProduceColor.color = color;}});}{label2.setBounds(10, 40, 54, 12);label2.setText("Label" + i);}GroupLayout gl_group_1 = new GroupLayout(group_1);gl_group_1.setHorizontalGroup(gl_group_1.createParallelGroup(GroupLayout.LEADING).add(button2,GroupLayout.DEFAULT_SIZE, 90, Short.MAX_VALUE).add(GroupLayout.TRAILING,gl_group_1.createSequentialGroup().add(10).add(label2,GroupLayout.DEFAULT_SIZE, 101, Short.MAX_VALUE).addContainerGap()));gl_group_1.setVerticalGroup(gl_group_1.createParallelGroup(GroupLayout.LEADING).add(GroupLayout.TRAILING,gl_group_1.createSequentialGroup().addContainerGap().add(button2, GroupLayout.DEFAULT_SIZE, 84,Short.MAX_VALUE).addPreferredGap(LayoutStyle.UNRELATED).add(label2).addContainerGap()));group_1.setLayout(gl_group_1);}}setScrollBar(scrolledComposite);}}

B：新建一个SWT Application Window类，通过选择上面的 SubScrollCompsite 为组件拖动到设计界面上进行布局。如下图：

然后，如图：

点击“OK”，这样就可以在设计界面上进行使用了。

（当然，也可以进行手动在代码中，进行添加组件）。

处理过后的源代码为：

package com.swtcomponent;import org.eclipse.swt.SWT;import org.eclipse.swt.events.MouseAdapter;import org.eclipse.swt.events.MouseEvent;import org.eclipse.swt.events.SelectionAdapter;import org.eclipse.swt.events.SelectionEvent;import org.eclipse.swt.graphics.Color;import org.eclipse.swt.graphics.Font;import org.eclipse.swt.graphics.GC;import org.eclipse.swt.graphics.Rectangle;import org.eclipse.swt.layout.FillLayout;import org.eclipse.swt.layout.grouplayout.GroupLayout;import org.eclipse.swt.widgets.Button;import org.eclipse.swt.widgets.Canvas;import org.eclipse.swt.widgets.Composite;import org.eclipse.swt.widgets.Display;import org.eclipse.swt.widgets.Shell;public class DemoTest {protected Shell shell;private SubScrollCompsite subScrollCompsite;private Canvas canvas;/** * Launch the application. *  * @param args */public static void main(String[] args) {try {DemoTest window = new DemoTest();window.open();} catch (Exception e) {e.printStackTrace();}}/** * Open the window. */public void open() {Display display = Display.getDefault();createContents();shell.open();shell.layout();while (!shell.isDisposed()) {if (!display.readAndDispatch()) {display.sleep();}}}/** * Create contents of the window. */protected void createContents() {shell = new Shell();shell.setSize(944, 664);shell.setText("SWT Application");shell.setLayout(new FillLayout(SWT.HORIZONTAL));Composite composite = new Composite(shell, SWT.NONE);{canvas = new Canvas(composite, SWT.BORDER);canvas.setBackground(new Color(Display.getDefault(), 200,200, 200));canvas.addMouseListener(new MouseAdapter() {@Overridepublic void mouseDown(MouseEvent e) {GC gc = new GC(canvas);Rectangle rect = canvas.getClientArea();gc.fillRectangle(rect.x, rect.y, rect.width,rect.height);gc.setForeground(ProduceColor.color);Font font = new Font(Display.getDefault(),"Arial", 32, SWT.BOLD);gc.setFont(font);gc.drawText("SHOW TEXT", e.x, e.y);}});}Button btnbutton = new Button(composite, SWT.NONE);btnbutton.addSelectionListener(new SelectionAdapter() {@Overridepublic void widgetSelected(SelectionEvent e) {showSomething(500);}});btnbutton.setText("500个Button");Button button_1 = new Button(composite, SWT.NONE);button_1.setText("改变字体颜色");GroupLayout gl_composite = new GroupLayout(composite);gl_composite.setHorizontalGroup(gl_composite.createParallelGroup(GroupLayout.LEADING).add(canvas, GroupLayout.DEFAULT_SIZE, 468,Short.MAX_VALUE).add(GroupLayout.TRAILING,gl_composite.createSequentialGroup().addContainerGap(125,Short.MAX_VALUE).add(button_1).add(68).add(btnbutton).add(131)));gl_composite.setVerticalGroup(gl_composite.createParallelGroup(GroupLayout.LEADING).add(gl_composite.createSequentialGroup().add(canvas,GroupLayout.DEFAULT_SIZE, 479, Short.MAX_VALUE).add(48).add(gl_composite.createParallelGroup(GroupLayout.BASELINE).add(btnbutton).add(button_1)).add(81)));composite.setLayout(gl_composite);{showSomething(300);}}public void showSomething(int count) {if (subScrollCompsite == null) {subScrollCompsite = new SubScrollCompsite(shell, count);} else {subScrollCompsite.showComposite(subScrollCompsite, shell, count);}}}

C：处理颜色的类为：

package com.swtcomponent;import java.util.Random;import org.eclipse.swt.graphics.Color;import org.eclipse.swt.graphics.RGB;import org.eclipse.swt.widgets.Display;public class ProduceColor {public static Color color;public Color produceColor() {Random random = new Random();int red = random.nextInt(255);int green = random.nextInt(255);int blue = random.nextInt(255);System.out.println("(" + red + "," + green + "," + blue + ")");RGB rgb = new RGB(red, green, blue);Color color = new Color(Display.getDefault(), rgb);return color;}}

D：实现完成，效果图为：

D：文章到此结束。

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