AS3.0中根据类名创建组件实例

最新推荐文章于 2019-09-07 16:33:38 发布

xiaolong2006

最新推荐文章于 2019-09-07 16:33:38 发布

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本文链接：https://blog.youkuaiyun.com/xiaolong2006/article/details/88642278

本文介绍了一种利用ActionScript 3.0中的getDefinitionByName方法动态创建UI组件实例的技术。通过实例展示了如何从字符串形式的类名创建不同类型的UI组件，并针对每种组件进行特定配置。

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本例将知识内涵iruguo通过调用类的getDefinitionByName()方法来创建组件实例。

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DE<<?xml version="1.0" encoding="utf-8"?>

<mx:Application name="getDefinitionByName_test"
        xmlns:mx="http://www.adobe.com/2006/mxml"
        layout="vertical"
        verticalAlign="middle"
        backgroundColor="white">

    <mx:Script>
        <![CDATA[
            import mx.core.UIComponent;
            import flash.utils.getDefinitionByName;
            import mx.controls.*;

            /**
             * Create references to component classes so the classes get
             * included in the SWF document.
             */
            private var dummyArr:Array = [Button, CheckBox, ComboBox,
                                            List, TextInput, TextArea];

            private function createBtn_click(evt:MouseEvent):void {
                var className:String = comboBox.selectedItem.toString();
                // Convert class name to Class object.
                var cls:Class = getDefinitionByName(className) as Class;

                // Create a new instance of the class.
                var instance:UIComponent = new cls();
                if (instance) {
                    switch (instance.className) {
                        case "Button":
                            Button(instance).label = "I am a Button";
                            break;
                        case "CheckBox":
                            CheckBox(instance).label = "I am a CheckBox";
                            break;
                        case "ComboBox":
                            ComboBox(instance).dataProvider = ["I am a ComboBox"];
                            break;
                        case "List":
                            List(instance).dataProvider = ["I am a List"];
                            instance.width = 100;
                            break;
                        case "TextInput":
                            TextInput(instance).text = "I am a TextInput";
                            break;
                        case "TextArea":
                            TextArea(instance).text = "I am a TextArea";
                            break;
                    }

                    // Remove all children and add new child.
                    canvas.removeAllChildren();
                    canvas.addChild(instance);
                }
            }
        ]]>
    </mx:Script>

    <mx:ApplicationControlBar dock="true">
        <mx:Form styleName="plain"
                defaultButton="{createBtn}">
            <mx:FormItem label="Class:"
                    direction="horizontal">
                <mx:ComboBox id="comboBox">
                    <mx:dataProvider>
                        <mx:Array>
                            <mx:String>mx.controls.Button</mx:String>
                            <mx:String>mx.controls.CheckBox</mx:String>
                            <mx:String>mx.controls.ComboBox</mx:String>
                            <mx:String>mx.controls.List</mx:String>
                            <mx:String>mx.controls.TextInput</mx:String>
                            <mx:String>mx.controls.TextArea</mx:String>
                        </mx:Array>
                    </mx:dataProvider>
                </mx:ComboBox>
                <mx:Button id="createBtn"
                        label="Create"
                        click="createBtn_click(event);" />
            </mx:FormItem>
        </mx:Form>
    </mx:ApplicationControlBar>

    <mx:Canvas id="canvas"
            horizontalCenter="0"
            verticalCenter="0" />

</mx:Application>
DE<

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