我遇到了位于 HBox 内的画布的尺寸问题。似乎“_graphic”、“_border”和“_fill”画布(在 com.example.ThingRenderer.mxml 中)没有与渲染器内的所有其他测量值同时进行测量。但是,此问题仅在第一次通过时观察到。请参阅图像以获得视觉效果... 第一张图像显示了应用程序完成加载后的状态。Populate
第二张图片代表点击按钮后屏幕的样子。第三张图片显示了当步进器增加时会发生什么。问题是,如何将数据填充到表格中后,第三张图像中的绘图不会被渲染?
渲染器测试.mxml
<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"
layout="absolute"
creationComplete="handleCreationComplete(event)"
>
<mx:Script>
<![CDATA[
import com.example.Thing;
import mx.collections.ArrayCollection;
import mx.events.FlexEvent;
import mx.events.NumericStepperEvent;
private const _thingProvider:ArrayCollection = new ArrayCollection();
private var _thing1:Thing;
protected function handleCreationComplete(event:FlexEvent):void {
_thing1 = new Thing("thingy", 0xff0000, 0.3);
_stepper.value = _thing1.ratio;
}
protected function handlePopulateClick(event:MouseEvent):void {
_thingProvider.addItem(_thing1);
}
protected function handleStepperChange(event:NumericStepperEvent):void {
_thing1.ratio = event.value;
}
]]>
</mx:Script>
<mx:VBox>
<mx:Button label="Populate" click="handlePopulateClick(event)" />
<mx:NumericStepper id="_stepper" minimum="0" maximum="1" stepSize="0.01" change="handleStepperChange(event)" />
<mx:AdvancedDataGrid dataProvider="{_thingProvider}" variableRowHeight="true" width="100%" height="100%">
<mx:columns>
<mx:AdvancedDataGridColumn headerText="Name" dataField="name" />
<mx:AdvancedDataGridColumn headerText="Display"
width="150" sortable="false"
itemRenderer="com.example.ThingRenderer"
/>
</mx:columns>
</mx:AdvancedDataGrid>
</mx:VBox>
</mx:Application>
com.exampleThingRenderer.mxml
<?xml version="1.0" encoding="utf-8"?>
<mx:Canvas
xmlns:mx="http://www.adobe.com/2006/mxml"
width="100%"
horizontalScrollPolicy="off" verticalScrollPolicy="off"
>
<mx:Script>
<![CDATA[
import mx.binding.utils.ChangeWatcher;
private var _thing:Thing;
private var _ratioWatcher:ChangeWatcher;
private var _doClearContent:Boolean;
private var _doDrawBorder:Boolean;
private var _doUpdateFill:Boolean;
override public function set data(value:Object):void {
if(value && value is Thing) {
_thing = Thing(value);
if(_ratioWatcher) {
_ratioWatcher.unwatch();
}
_ratioWatcher = ChangeWatcher.watch(_thing, "ratio", handleRatioChanged);
_doClearContent = false;
_doDrawBorder = true;
_doUpdateFill = true;
_graphic.invalidateSize();
_border.invalidateSize();
}
else {
_doClearContent = true;
_doDrawBorder = false;
_doUpdateFill = false;
}
super.data = value;
}
private function handleRatioChanged(event:Event):void {
_doUpdateFill = true;
invalidateDisplayList();
}
override protected function updateDisplayList(unscaledWidth:Number, unscaledHeight:Number):void {
if(_doClearContent) {
_container.visible = false;
_container.includeInLayout = false;
_doClearContent = false;
}
super.updateDisplayList(unscaledWidth, unscaledHeight);
if(_doDrawBorder) {
trace("_thingContainer.width="+_container.width, "_thingGraphic.width="+_graphic.width, "_thingBorder.width="+_border.width);
_border.graphics.clear();
_border.graphics.moveTo(0, 0);
_border.graphics.lineStyle(1, _thing.color);
_border.graphics.lineTo(_border.width, 0);
_border.graphics.lineTo(_border.width, _border.height);
_border.graphics.lineTo(0, _border.height);
_border.graphics.lineTo(0, 0);
_doDrawBorder = false;
}
if(_doUpdateFill) {
_percentage.text = Math.round(_thing.ratio * 100.0) + "%";
_fill.graphics.clear();
_fill.graphics.beginFill(_thing.color);
_fill.graphics.drawRect(0, 0, _fill.width * _thing.ratio, _fill.height);
_doUpdateFill = false;
}
}
]]>
</mx:Script>
<mx:HBox id="_container" width="100%" paddingLeft="5" paddingTop="5" paddingRight="5" paddingBottom="5">
<mx:Label id="_percentage" width="45" />
<mx:Canvas id="_graphic" width="100%" height="15">
<mx:Canvas id="_border" x="0" y="0" width="100%" height="100%" />
<mx:Canvas id="_fill" x="0" y="0" width="100%" height="100%" />
</mx:Canvas>
</mx:HBox>
</mx:Canvas>
com.example.Thing.as
package com.example {
public class Thing {
[Bindable] public var name:String;
[Bindable] public var color:uint;
[Bindable] public var ratio:Number;
public function Thing(name:String, color:uint, ratio:Number) {
this.name = name;
this.color = color;
this.ratio = ratio;
}
}
}