Le changement dynamique de la largeur de la colonne de grille de données dans FLEX

C'est ce que je suis venu avec toutefois, il peut ne pas être efficace pour les grands fournisseurs de données:

<?xml version="1.0" encoding="utf-8"?>
<mx:WindowedApplication xmlns:mx="http://www.adobe.com/2006/mxml"
creationComplete="onComplete();">
<mx:Script>
<![CDATA[
//imports:
import mx.events.FlexEvent;
import mx.core.UIComponent;
import mx.controls.dataGridClasses.DataGridColumn;
import mx.controls.Text;
import mx.utils.ObjectUtil;
import mx.controls.Label;
import mx.collections.ArrayCollection;
//data provider:
[Bindable] private var dp:ArrayCollection = new ArrayCollection();
private function onComplete():void {
//populate data provider here
//to avoid calcMaxLengths execution when the app is created:
dp = new ArrayCollection(
[
{ col1: "Short", col2: "Other column 1" },
{ col1: "Some long string", col2: "Other column 2" },
{ col1: "Short", col2: "Other column 3" },
{ col1: "Short", col2: "Other column 4" },
{ col1: "The longest value in this column", col2: "Other column 5" },
{ col1: "Short", col2: "Other column 6" },
{ col1: "Short", col2: "Other column 7" }
]
);
}
//this is going to be executed whenever the data provider changes:
[Bindable("dataChange")]
private function calcMaxLengths(input:ArrayCollection):ArrayCollection {
//if there are items in the DP:
if ( input.length > 0 ) {
//and no SPECIAL child exists:
if ( getChildByName("$someTempUICToRemoveAfterFinished") == null ) {
//create new SPECIAL child
//this is required to call measureText
//if you use custom data grid item renderer
//then create instance of it instead of UIComponent:
var uic:UIComponent = new UIComponent();
//do not show and do not mess with the sizes:
uic.includeInLayout = false;
uic.visible = false;
//name it to leverage get getChildByName method:
uic.name = "$someTempUICToRemoveAfterFinished";
//add event listener:
uic.addEventListener(FlexEvent.CREATION_COMPLETE, onTempUICCreated);
//add to parent:
addChild(uic);
}
}
//return an input:
return input;
}
//called when SPECIAL child is created:
private function onTempUICCreated(event:FlexEvent):void {
//keep the ref to the SPECIAL child:
var renderer:UIComponent = UIComponent(event.target);
//output - this will contain max size for each column:
var maxLengths:Object = {};
//temp variables:
var key:String = "";
var i:int=0;
//for each item in the DP:
for ( i=0; i<dp.length; i++ ) {
var o:Object = dp.getItemAt(i);
// for each key in the DP row:
for ( key in o ) {
// if the output doesn't have current key yet create it and set to 0:
if ( !maxLengths.hasOwnProperty(key) ) {
maxLengths[key] = 0;
}
//check if it's simple object (may cause unexpected issues for Boolean):
if ( ObjectUtil.isSimple(o[key]) ) {
// measure the text:
var cellMetrics:TextLineMetrics = renderer.measureText(o[key]+"");
// and if the width is greater than longest found up to now:
if ( cellMetrics.width > maxLengths[key] ) {
//set it as the longest one:
maxLengths[key] = cellMetrics.width;
}
}
}
}
//apply column sizes:
for ( key in maxLengths ) {
for ( i=0; i<dg.columnCount; i++ ) {
// if the column actually exists:
if ( DataGridColumn(dg.columns[i]).dataField == key ) {
// set size + some constant margin
DataGridColumn(dg.columns[i]).width = Number(maxLengths[key]) + 12;
}
}
}
// cleanup:
removeChild(getChildByName("$someTempUICToRemoveAfterFinished"));
}
]]>
</mx:Script>
<mx:DataGrid id="dg" horizontalScrollPolicy="on" dataProvider="{calcMaxLengths(dp)}" width="400">
<mx:columns>
<mx:DataGridColumn dataField="col1" width="40" />
<mx:DataGridColumn dataField="col2" width="100" />
</mx:columns>
</mx:DataGrid>
</mx:WindowedApplication>

OriginalL'auteur radekg

Pour le contrôle Gridview, vous pouvez zoomer sur la SelectedRowStyle de la propriété et de l'ensemble de la pellicule pour Vrai.

OriginalL'auteur Cameron