GWT - GWT Designer开发Ajax应用 (06) - 常用控件使用
http://blog.csdn.net/pathuang68/article/details/4272424
概要说明:
Tab、RadioButton和ComboBox的使用方法。
1.
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图1
设定项目名称为:TestSeveralWidgets,点击Finish按钮:
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图2
做一下工作:
-?选中Create GWT Module
-?将Module Name设为:TestSeveralWidgets
-?将Package Name设为:com.pnft.ajax
点击Finish按钮。
?
做完这些工作后,这个新建的项目大致是这样的:
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图3
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选中src目录,修改项目属性,使其字符集为UTF-8。因为后面我们要用到中文。?
注意:创建GWT Project的详细过程,请见GWT Designer04。
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2.?新建一个Composite
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图4
如下图将Composite的Name设定为:TestSeveralWidgetsComposite。
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图5
点击Finish按钮。做完这些工作后Composite的情况大致如下:
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图6
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3.?切换到TestSeveralWidgetsComposite的Design视图
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图7
?
选中Palette中的TabPanel,
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图8
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放置到Empty Composite上,得到:
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图9
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4.?在Palette中选中AbsolutePanel,
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图10
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将AbsolutePanel放置到步骤3中TabPanel上,得到:
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图11
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修改刚才放置的AbsolutePanel的属性:
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图12
- variable:??????????absolutePanel1
- height:?????????????300px
- styleName:?????tabpanel
- tab title:????????????First Tab
?
?
其中,tabpanel是新增加的css,其内容如下图:
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图13
注意在新增css时,前面的“.”不能去掉(如上图所示“.tabpanel”),但在程序中或者属性栏中,使用或显示的均是“tabpanel”,
比如,前面属性修改完成后,GWT Designer会在程序中自动为我们生成一些代码,其中有:
????absolutePanel1.setStyleName("tabpanel");
这就是在程序中引用css的方法。
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5.?重复4,再增加一个tab(在红线处)
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图14
其属性修改情况如下:
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图15
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6.?在First Tab (即absolutePanel1)上增加一个Label、一个TextBox和一个按钮:
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图16
增加.gwt-button这个css
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7.?在第二个Tab (即absolutePanel2)上增加6个Radio Button:
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图17
6个RadioButton分成两组:
group1:
variable: radioButton1???????text:?单选按钮一
variable: radioButton2???????text:?单选按钮二
variable: radioButton3???????text:?单选按钮三
group2:
variable: radioButton4???????text:?单选按钮四
variable: radioButton5???????text:?单选按钮五
variable: radioButton6???????text:?单选按钮六
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8.?继续在第二个Tab (即absolutePanel2)上增加一个ComboBox:
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图18
variable:?????????????comboBox
修改items属性:
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图19
点击OK按钮。
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预览一下我们的设计:
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图20
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9.?修改GWT Designer自动生成的代码。到目前为止,GWT Designer为我们生成了一下代码:
public?class?TestSeveralWidgetsComposite?extends?Composite
{
????public?TestSeveralWidgetsComposite()
{
????????final?TabPanel tabPanel =?new?TabPanel();
????????initWidget(tabPanel);
?
????????final?AbsolutePanel absolutePanel1 =?new?AbsolutePanel();
????????tabPanel.add(absolutePanel1,?"First Tab");
????????absolutePanel1.setStyleName("tabpanel");
????????absolutePanel1.setHeight("300px");
?
????????final?Label label =?new?Label("New Label");
????????absolutePanel1.add(label, 38, 64);
?
????????final?TextBox textBox =?new?TextBox();
????????absolutePanel1.add(textBox, 109, 58);
?
????????final?Button okButtonOK =?new?Button();
????????absolutePanel1.add(okButtonOK, 276, 57);
????????okButtonOK.setText("OK");
?
????????final?AbsolutePanel absolutePanel2 =?new?AbsolutePanel();
????????tabPanel.add(absolutePanel2,?"第二个Tab");
????????absolutePanel2.setStyleName("tabpanel");
????????absolutePanel2.setHeight("300px");
?
????????final?RadioButton radioButton1 =?new?RadioButton("group1");
????????absolutePanel2.add(radioButton1, 39, 73);
????????radioButton1.setText("单选按钮一");
?
????????final?RadioButton radioButton2 =?new?RadioButton("group1");
????????absolutePanel2.add(radioButton2, 39, 98);
????????radioButton2.setText("单选按钮二");
?
????????final?RadioButton radioButton3 =?new?RadioButton("group1");
????????absolutePanel2.add(radioButton3, 39, 123);
????????radioButton3.setText("单选按钮三");
?
????????final?RadioButton radioButton4 =?new?RadioButton("group2");
????????absolutePanel2.add(radioButton4, 246, 73);
????????radioButton4.setText("单选按钮四");
?
????????final?RadioButton radioButton5 =?new?RadioButton("group2");
????????absolutePanel2.add(radioButton5, 246, 98);
????????radioButton5.setText("单选按钮五");
?
????????final?RadioButton radioButton6 =?new?RadioButton("group2");
????????absolutePanel2.add(radioButton6, 246, 123);
????????radioButton6.setText("单选按钮六");
?
????????final?ListBox comboBox =?new?ListBox();
????????absolutePanel2.add(comboBox, 39, 181);
????????comboBox.addItem("");
????????comboBox.addItem("谁家玉笛暗飞声,");
????????comboBox.addItem("散入春风满洛城。");
????????comboBox.addItem("此夜曲中闻折柳,");
????????comboBox.addItem("何人不起故园情。");
????????comboBox.addItem("一树寒梅白玉条,");
????????comboBox.addItem("迥邻村路傍溪桥。");
????????comboBox.addItem("不知近水花先发,");
????????comboBox.addItem("疑是经冬雪未消。");
????????comboBox.addItem("湖光秋月两相和,");
????????comboBox.addItem("潭面无风镜未磨。");
????????comboBox.addItem("遥望洞庭山水翠,");
????????comboBox.addItem("白银盘里一青螺。");
????????comboBox.setWidth("287px");
????????tabPanel.selectTab(0);
????}
}
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修改上面的代码,将所有widget从构造方法TestSeveralWidgetsComposite中提出来,使其作为类的私有成员变量,修改后的代码如下:
public?class?TestSeveralWidgetsComposite?extends?Composite
{
????private?TabPanel?tabPanel;
????private?AbsolutePanel?absolutePanel1;
????private?Label?label;
????private?TextBox?textBox;
????private?Button?okButtonOK;
????private?AbsolutePanel?absolutePanel2;
????private?RadioButton?radioButton1;
????private?RadioButton?radioButton2;
????private?RadioButton?radioButton3;
????private?RadioButton?radioButton4;
????private?RadioButton?radioButton5;
????private?RadioButton?radioButton6;
????private?ListBox?comboBox;
?
????public?TestSeveralWidgetsComposite()
????{
????????tabPanel?=?new?TabPanel();
????????initWidget(tabPanel);
?
????????absolutePanel1?=?new?AbsolutePanel();
????????tabPanel.add(absolutePanel1,?"First Tab");
????????absolutePanel1.setStyleName("tabpanel");
????????absolutePanel1.setHeight("300px");
?
????????label?=?new?Label("New Label");
????????absolutePanel1.add(label, 38, 64);
?
????????textBox?=?new?TextBox();
????????absolutePanel1.add(textBox, 109, 58);
?
????????okButtonOK?=?new?Button();
????????absolutePanel1.add(okButtonOK, 276, 57);
????????okButtonOK.setText("OK");
?
????????absolutePanel2?=?new?AbsolutePanel();
????????tabPanel.add(absolutePanel2,?"第二个Tab");
????????absolutePanel2.setStyleName("tabpanel");
????????absolutePanel2.setHeight("300px");
?
????????radioButton1?=?new?RadioButton("group1");
????????absolutePanel2.add(radioButton1, 39, 73);
????????radioButton1.setText("单选按钮一");
?
????????radioButton2?=?new?RadioButton("group1");
????????absolutePanel2.add(radioButton2, 39, 98);
????????radioButton2.setText("单选按钮二");
?
????????radioButton3?=?new?RadioButton("group1");
????????absolutePanel2.add(radioButton3, 39, 123);
????????radioButton3.setText("单选按钮三");
?
????????radioButton4?=?new?RadioButton("group2");
????????absolutePanel2.add(radioButton4, 246, 73);
????????radioButton4.setText("单选按钮四");
?
????????radioButton5?=?new?RadioButton("group2");
????????absolutePanel2.add(radioButton5, 246, 98);
????????radioButton5.setText("单选按钮五");
?
????????radioButton6?=?new?RadioButton("group2");
????????absolutePanel2.add(radioButton6, 246, 123);
????????radioButton6.setText("单选按钮六");
?
????????comboBox?=?new?ListBox();
????????absolutePanel2.add(comboBox, 39, 181);
????????comboBox.addItem("");
????????comboBox.addItem("谁家玉笛暗飞声,");
????????comboBox.addItem("散入春风满洛城。");
????????comboBox.addItem("此夜曲中闻折柳,");
????????comboBox.addItem("何人不起故园情。");
????????comboBox.addItem("一树寒梅白玉条,");
????????comboBox.addItem("迥邻村路傍溪桥。");
????????comboBox.addItem("不知近水花先发,");
????????comboBox.addItem("疑是经冬雪未消。");
????????comboBox.addItem("湖光秋月两相和,");
????????comboBox.addItem("潭面无风镜未磨。");
????????comboBox.addItem("遥望洞庭山水翠,");
????????comboBox.addItem("白银盘里一青螺。");
????????comboBox.setWidth("287px");
????????tabPanel.selectTab(0);
????}
}
这样做的好处是,如果在类中增加了其他方法,那么其他方法也可以访问到这些widget,而前面那种方法是不方便的。
?
?
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10.?增加单选按钮消息处理方法
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图21
GWT Designer将自动生成下面带下划线的代码:
????????radioButton1?=?new?RadioButton("group1");
????????absolutePanel2.add(radioButton1, 39, 73);
????????radioButton1.addClickListener(new?ClickListener()
????????{
????????????public?void?onClick(final?Widget sender)
????????????{
????????????}
????????});
????????radioButton1.setText("单选按钮一");
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可以采用同样的方法,给其他Widget增加消息处理方法。
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但我们也可以采用另外一种方式,即将上面的代码带下划线的部分改为下面带下划线的代码:
????????radioButton1?=?new?RadioButton("group1");
????????absolutePanel2.add(radioButton1, 39, 73);
????????radioButton1.addClickListener(this);
????????radioButton1.setText("单选按钮一");
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这时MyEclipse认为有问题了:
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图22
选中最后一条,即“Let ‘TestSeveralWidgetsComposite’ implement ‘ClickListener’”,就是说让类
TestSeveralWidgetsComposite实现接口ClickListener。
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但到此MyEclipse还是在提示问题,这是因为接口ClickListener中由一个onClick方法,TestSeveralWidgetsComposite类必须要实现它。
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图23
选择“Add unimplemented methods”,
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图24
注意:去掉@Override这个annotation,GWT 1.4.62(支持jdk1.4-)不支持java1.5中开始有的标注特性。
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到此,MyEclipse不提示错误信息了。现在为radioButton2 ~ 6增加消息监听器,就像radioButton1那样:
????…
????radioButton2.addClickListener(this);
?????????...
????radioButton2.addClickListener(this);
?????????...
radioButton2.addClickListener(this);
?????????...
????radioButton2.addClickListener(this);
?????????...
????radioButton2.addClickListener(this);
?????????…
?
修改类的onClick方法,使之如下:
????public?void?onClick(Widget sender)
????{
????????if(sender ==?radioButton1)
????????{
????????????if(radioButton1.isChecked())
????????????{
????????????????Window.alert("RadioButton1 is checked...");
????????????}
????????}
????????else?if(sender ==?radioButton2)
????????{
????????????if(radioButton2.isChecked())
????????????{
????????????????Window.alert("RadioButton2 is checked...");
????????????}
????????}
????????else?if(sender ==?radioButton3)
????????{
????????????if(radioButton3.isChecked())
????????????{
????????????????Window.alert("RadioButton3 is checked...");
????????????}
????????}
????????else?if(sender ==?radioButton4)
????????{
????????????if(radioButton4.isChecked())
????????????{
????????????????Window.alert("RadioButton4 is checked...");
????????????}
????????}
????????else?if(sender ==?radioButton5)
????????{
????????????if(radioButton5.isChecked())
????????????{
????????????????Window.alert("RadioButton5 is checked...");
????????????}
????????}
????????else?if(sender ==?radioButton6)
????????{
????????????if(radioButton6.isChecked())
????????????{
????????????????Window.alert("RadioButton6 is checked...");
????????????}
????????}
????}
?
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11.?增加comboBox的消息处理方法
?
图25
增加了下面带下划线的代码(当然也可以象10中那样进行处理):
????????comboBox?=?new?ListBox();
????????absolutePanel2.add(comboBox, 39, 181);
????????comboBox.addChangeListener(new?ChangeListener()
????????{
????????????public?void?onChange(final?Widget sender)
????????????{
????????????}
????????});
????????comboBox.addItem("");
????????comboBox.addItem("谁家玉笛暗飞声,");
????????comboBox.addItem("散入春风满洛城。");
????????comboBox.addItem("此夜曲中闻折柳,");
????????comboBox.addItem("何人不起故园情。");
????????comboBox.addItem("一树寒梅白玉条,");
????????comboBox.addItem("迥邻村路傍溪桥。");
????????comboBox.addItem("不知近水花先发,");
????????comboBox.addItem("疑是经冬雪未消。");
????????comboBox.addItem("湖光秋月两相和,");
????????comboBox.addItem("潭面无风镜未磨。");
????????comboBox.addItem("遥望洞庭山水翠,");
????????comboBox.addItem("白银盘里一青螺。");
????????comboBox.setWidth("287px");
?
?????????修改上面带下划线的代码为:
????????comboBox.addChangeListener(new?ChangeListener()
????????{
????????????public?void?onChange(final?Widget sender)
????????????{
????????????????int?i =?comboBox.getSelectedIndex();
????????????????String z =?comboBox.getItemText(i);
????????????????Window.alert("Item "?+ i +?"'s text is "?+ z);
????????????}
????????});
?
?
12.?注意,两个不同Tab之间的Widget的variable必须唯一,不可重复。如在Tab1中有一个Widget对应的variable是“button”,那么在Tab2中就不可能有另外Widget对应的variable是“button”。
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13.?将Tab1中的textBox,Tab2中的6个RadioButton和CombBox等Widget,用类似下图所示的方法进行Expose,这样就会让引用TestSeveralWidgetsComposite这个控件的其他应用,对TestSeveralWidgetsComposite中被Expose了的widget直接进行存取(见16)。
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图26
到此,整个Composite的开发工作告一段落。
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14.?在TestSeveralWidgets类中引用上面开发好的TestSeveralWidgetsComposite。
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图27
点击Palette中的Choose Widget,
如下图,输入TestSeveralWidgetsComposite的名字,还未输入完成的时候,便可以在下面的文本框中看到我们想要引用的TestSeveralWidgetsComposite,选中它,
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图28
点击OK按钮,在适当位置放置TestSeveralWidgetsComposite,如下图:
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图29
调整TestSeveralWidgetsComposite的大小和位置,使之如下:
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图30
这将会在TestSeveralWidgets类中的onModuleLoad方法的最后增加以下代码:
final?TestSeveralWidgetsComposite testSeveralWidgetsComposite =?new
TestSeveralWidgetsComposite();
????????rootPanel.add(testSeveralWidgetsComposite, 10, 10);
????????testSeveralWidgetsComposite.setSize("580px",?"358px");
?
修改上面的代码,将testSeveralWidgetsComposite作为类的私有成员。修改后TestSeveralWidgets类的代码如下:
…
public?class?TestSeveralWidgets?implements?EntryPoint
{
????private?TestSeveralWidgetsComposite?testSeveralWidgetsComposite;
????private?Button?clickMeButton;
?
????public?void?onModuleLoad()
????{
????????RootPanel rootPanel = RootPanel.get();
?
????????clickMeButton?=?new?Button();
????????rootPanel.add(clickMeButton, 265, 380);
????????clickMeButton.setText("Click me!");
????????clickMeButton.addClickListener(new?ClickListener()
????????{
????????????public?void?onClick(Widget sender)
????????????{
????????????????Window.alert("Hello, GWT World!");
????????????}
????????});
?
????????testSeveralWidgetsComposite?=?new?TestSeveralWidgetsComposite();
????????rootPanel.add(testSeveralWidgetsComposite, 10, 10);
????????testSeveralWidgetsComposite.setSize("580px",?"358px");
????}
…
?
15.?在hosted mode下的运行结果:
?
图31?
?
图32
??
图33
?
图34
应用的表现和我们预想的完全一致。
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16.?增加Clickme按钮的代码,使得当点击Click Me按钮时,能够将Tab1?和Tab2中的Widget的状态合在一起显示出来。修改后整个TestSeveralWidgets类的代码如下:
public?class?TestSeveralWidgets?implements?EntryPoint
{
????private?TestSeveralWidgetsComposite?testSeveralWidgetsComposite;
????private?Button?clickMeButton;
?
????public?void?onModuleLoad()
????{
????????RootPanel rootPanel = RootPanel.get();
?
????????clickMeButton?=?new?Button();
????????rootPanel.add(clickMeButton, 265, 380);
????????clickMeButton.setText("Click me!");
????????clickMeButton.addClickListener(new?ClickListener()
????????{
????????????public?void?onClick(Widget sender)
????????????{
????????????????String summary;
????????????????//?获取Tab1中的文本框中的文字
????????????????summary =?testSeveralWidgetsComposite.getTextBox().getText();
????????????????//?获取RadioButton 1~6的状态,未考虑代码之优雅程度
????????????????if(testSeveralWidgetsComposite.getRadioButton1().isChecked()) summary +=
"/nRadio Button 1 is checked.";
????????????????if(testSeveralWidgetsComposite.getRadioButton2().isChecked()) summary +=
"/nRadio Button 2 is checked.";
????????????????if(testSeveralWidgetsComposite.getRadioButton3().isChecked()) summary +=
"/nRadio Button 3 is checked.";
????????????????if(testSeveralWidgetsComposite.getRadioButton4().isChecked()) summary +=
"/nRadio Button 4 is checked.";
????????????????if(testSeveralWidgetsComposite.getRadioButton5().isChecked()) summary +=
"/nRadio Button 5 is checked.";
????????????????if(testSeveralWidgetsComposite.getRadioButton6().isChecked()) summary +=
"/nRadio Button 6 is checked.";
?
????????????????//?获取ComboBox中被选中Item的index
????????????????int?index =?testSeveralWidgetsComposite.getComboBox().getSelectedIndex();
????????????????//?获取ComboBox中被选中Item的text,并加入到summary中
????????????????summary +=?"/n"?+
testSeveralWidgetsComposite.getComboBox().getItemText(index);
?
????????????????Window.alert(summary);
????????????}
????????});
?
????????testSeveralWidgetsComposite?=?new?TestSeveralWidgetsComposite();
????????rootPanel.add(testSeveralWidgetsComposite, 10, 10);
????????testSeveralWidgetsComposite.setSize("580px",?"358px");
????}
}
?
17.?再次在hosted mode下运行。
?
图35
如下图,在First Tab中输入“玄机逸士之武功研究”
?
图36
点击“第二个Tab”,并做出如下图所示的选择:?
?
图37
点击Click me!按钮,得到:
?
图38
所得结果和预想相同。
?
18.?部署到Tomcat6上,并在IE6和FireFox3中运行。
?
图39
?
图40
点击OK按钮,开始部署。下图是部署成功后的情形:
?
图41
?
启动Tomcat6,如果还没有启动的话。
?
?
IE中的运行结果:
?
图42
点击“第二个Tab”,并做出如下图所示的选择:
?
图43
点击Click me!按钮,得到:
?
图44
结果正确。
?
FireFox3中的运行结果与上相同,略。