GWT - SuggestionBox 小部件

简介

SuggestionBox 小部件表示一个文本框或文本区域，显示一组与用户输入相匹配的预配​​置选择。每个 SuggestBox 都与一个 SuggestOracle 相关联。SuggestOracle 用于根据特定查询字符串提供一组选择。

类声明

以下是 com.google.gwt.user.client.ui.SuggestionBox 类的声明 −

public final class SuggestBox
   extends Composite
      implements HasText, HasFocus, HasAnimation, 
         SourcesClickEvents, SourcesFocusEvents, 
            SourcesChangeEvents, SourcesKeyboardEvents, 
               FiresSuggestionEvents

CSS 样式规则

以下默认 CSS 样式规则将应用于所有 ListBox 小部件。您可以根据需要覆盖它。

.gwt-SuggestBox { }

.gwt-SuggestBoxPopup { }

.gwt-SuggestBoxPopup .item { }

.gwt-SuggestBoxPopup .item-selected { }

.gwt-SuggestBoxPopup .suggestPopupTopLeft { }

.gwt-SuggestBoxPopup .suggestPopupTopLeftInner { }

.gwt-SuggestBoxPopup .suggestPopupTopCenter { }

.gwt-SuggestBoxPopup .suggestPopupTopCenterInner { }

.gwt-SuggestBoxPopup .suggestPopupTopRight { }

.gwt-SuggestBoxPopup .suggestPopupTopRightInner { }

.gwt-SuggestBoxPopup .suggestPopupMiddleLeft { }

.gwt-SuggestBoxPopup .suggestPopupMiddleLeftInner { }

.gwt-SuggestBoxPopup .suggestPopupMiddleCenter { }

.gwt-SuggestBoxPopup .suggestPopupMiddleCenterInner { }

.gwt-SuggestBoxPopup .suggestPopupMiddleRight { }

.gwt-SuggestBoxPopup .suggestPopupMiddleRightInner { }

.gwt-SuggestBoxPopup .suggestPopupBottomLeft { }

.gwt-SuggestBoxPopup .suggestPopupBottomLeftInner { }

.gwt-SuggestBoxPopup .suggestPopupBottomCenter { }

.gwt-SuggestBoxPopup .suggestPopupBottomCenterInner { }

.gwt-SuggestBoxPopup .suggestPopupBottomRight { }

.gwt-SuggestBoxPopup .suggestPopupBottomRightInner { }

类构造函数

类方法

继承的方法

该类继承了以下类的方法 −

• com.google.gwt.user.client.ui.UIObject

• com.google.gwt.user.client.ui.Widget

• com.google.gwt.user.client.ui.Composite

• java.lang.Object

SuggestionBox 小部件示例

此示例将带您通过简单的步骤展示 GWT 中 SuggestionBox 小部件的使用方法。按照以下步骤更新我们在 GWT - 创建应用程序 一章中创建的 GWT 应用程序 −

以下是修改后的模块描述符src/com.tutorialspoint/HelloWorld.gwt.xml的内容。

<?xml version = "1.0" encoding = "UTF-8"?>
<module rename-to = 'helloworld'>
   <!-- Inherit the core Web Toolkit stuff.                        -->
   <inherits name = 'com.google.gwt.user.User'/>

   <!-- Inherit the default GWT style sheet.                       -->
   <inherits name = 'com.google.gwt.user.theme.clean.Clean'/>

   <!-- Specify the app entry point class.                         -->
   <entry-point class = 'com.tutorialspoint.client.HelloWorld'/>

   <!-- Specify the paths for translatable code                    -->
   <source path = 'client'/>
   <source path = 'shared'/>

</module>

以下是修改后的样式表文件war/HelloWorld.css的内容。

body {
   text-align: center;
   font-family: verdana, sans-serif;
}

h1 {
   font-size: 2em;
   font-weight: bold;
   color: #777777;
   margin: 40px 0px 70px;
   text-align: center;
}

.gwt-SuggestBox { 
   color: green;
}

.gwt-SuggestBoxPopup { 
   border: thin 1px solid green; 
   width: 200px;
}

.gwt-SuggestBoxPopup.item { 
   color: red; 
}

.gwt-SuggestBoxPopup .item-selected { 
   color: gray;
}

.gwt-SuggestBoxPopup .suggestPopupTopLeft { 
   border: thin 1px solid green; 
}

.gwt-SuggestBoxPopup .suggestPopupTopLeftInner { 
   border: thin 1px solid green; 
}

.gwt-SuggestBoxPopup .suggestPopupTopCenter { 
   border: thin 1px solid green; 
}

.gwt-SuggestBoxPopup .suggestPopupTopCenterInner { 
   border: thin 1px solid green; 
}

.gwt-SuggestBoxPopup .suggestPopupTopRight {
   border: thin 1px solid green; 
}

.gwt-SuggestBoxPopup .suggestPopupTopRightInner {
   border: thin 1px solid green; 
}

.gwt-SuggestBoxPopup .suggestPopupMiddleLeft { 
   border: thin 1px solid green;
}

.gwt-SuggestBoxPopup .suggestPopupMiddleLeftInner { 
   border: thin 1px solid green;
}

.gwt-SuggestBoxPopup .suggestPopupMiddleCenter { 
   border: thin 1px solid green; width:200px;
}

.gwt-SuggestBoxPopup .suggestPopupMiddleCenterInner { 
   border: thin 1px solid green;
}

.gwt-SuggestBoxPopup .suggestPopupMiddleRight { 
   border: thin 1px solid green;
}

.gwt-SuggestBoxPopup .suggestPopupMiddleRightInner { 
   border: thin 1px solid green;
}

.gwt-SuggestBoxPopup .suggestPopupBottomLeft {
   border: thin 1px solid green;
}

.gwt-SuggestBoxPopup .suggestPopupBottomLeftInner { 
   border: thin 1px solid green;
}

.gwt-SuggestBoxPopup .suggestPopupBottomCenter {
   border: thin 1px solid green;
 }

.gwt-SuggestBoxPopup .suggestPopupBottomCenterInner { 
   border: thin 1px solid green;
}

.gwt-SuggestBoxPopup .suggestPopupBottomRight { 
   border: thin 1px solid green;
}

.gwt-SuggestBoxPopup .suggestPopupBottomRightInner { 
   border: thin 1px solid green;
}

以下是修改后的 HTML 主机文件 war/HelloWorld.html 的内容。

<html>
   <head>
      <title>Hello World</title>
      <link rel = "stylesheet" href = "HelloWorld.css"/>
      <script language = "javascript" src = "helloworld/helloworld.nocache.js">
      </script>
   </head>

   <body>
      <h1>SuggestionBox Widget Demonstration</h1>
      <div id = "gwtContainer"></div>
   </body>
</html>

让我们来看看 Java 文件 src/com.tutorialspoint/HelloWorld.java 的以下内容，它将演示如何使用 SuggestionBox 小部件。

package com.tutorialspoint.client;

import com.google.gwt.core.client.EntryPoint;
import com.google.gwt.user.client.ui.MultiWordSuggestOracle;
import com.google.gwt.user.client.ui.RootPanel;
import com.google.gwt.user.client.ui.SuggestBox;
import com.google.gwt.user.client.ui.VerticalPanel;

public class HelloWorld implements EntryPoint {
   public void onModuleLoad() {
    //创建建议数据
    MultiWordSuggestOracle oracle = new MultiWordSuggestOracle();  
    oracle.add("A");
    oracle.add("AB");
    oracle.add("ABC");
    oracle.add("ABCD");
    oracle.add("B");
    oracle.add("BC");
    oracle.add("BCD");
    oracle.add("BCDE");
    oracle.add("C");
    oracle.add("CD");
    oracle.add("CDE");
    oracle.add("CDEF");
    oracle.add("D");
    oracle.add("DE");
    oracle.add("DEF");
    oracle.add("DEFG");
      
    //创建建议框并向其传递上面创建的数据
    SuggestBox suggestionsBox = new SuggestBox(oracle);
    
    //将宽度设置为 200px。
    suggestionsBox.setWidth("200");
    
    // 将建议框添加到根面板。
    VerticalPanel panel = new VerticalPanel();
    panel.add(suggestionBox);
    
    RootPanel.get("gwtContainer").add(panel);
   }	
}

完成所有更改后，让我们像在 GWT - 创建应用程序 一章中一样，在开发模式下编译并运行应用程序。如果您的应用程序一切正常，这将产生以下结果 −

gwt_form_widgets.html