我们可以通过单击列的边框来动态更改datagrid列的宽度，以显示太长而无法显示并需要滚动的完整字符串吗？如果是这样，怎么样？
另外，我们如何确保列宽根据字符数/字符串长度动态变化;因为很多次数据太长而无法显示。我们可以设置列宽以在显示到数据网格之前考虑数据的长度吗？
答案 0 :(得分：2)
所以我遇到了类似的问题，这就是我找到的。如果你设置：
horizontalScrollPolicy="off"
然后列宽将自动调整大小以适应DataGrid的宽度。您也可以手动设置列宽，只要滚动设置为打开或关闭，而不设置为自动。我发现了一篇有趣的文章，http://junleashed.wordpress.com/2008/07/10/flex-datagridcolumn-width-management/。基本上，他手动管理列宽，然后计算滚动条是打开还是关闭。
答案 1 :(得分：1)
这是我提出的，但对大型数据提供商而言可能效率不高：
<?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>
答案 2 :(得分：1)
我最近遇到了同样的问题，我找到的唯一解决方案是使用自定义函数，根据建议here优化DataGrid的列宽：
<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml">
<mx:Script>
<![CDATA[
import mx.core.UITextField;
import mx.controls.dataGridClasses.DataGridItemRenderer;
public function optimiseGridColumns(dg:DataGrid):void {
var dgCol:DataGridColumn;
var renderer:UITextField;
var tf:TextFormat;
var col:int;
if (dg.columnCount > 0 && dg.dataProvider != null) {
// initialize widths array
var widths:Array = new Array (dg.columnCount);
for (col = 0; col < widths.length; ++col) {
widths[col] = -1;
}
// go through each data item in the grid, estimate
// the width of the text in pixels
for each (var item:Object in dg.dataProvider) {
for (col = 0; col < widths.length; ++col) {
renderer = new DataGridItemRenderer();
// Must add to datagrid as child so that it inherits
// properties essential for text width estimation,
// such as font size
dg.addChild(renderer);
dgCol = dg.columns[col] as DataGridColumn;
renderer.text = dgCol.itemToLabel(item);
widths[col] = Math.max(renderer.measuredWidth + 10,widths[col]);
// remove renderer from datagrid when we're done
dg.removeChild(renderer);
}
}
// go through headers in the grid, estimate the width of
// the text in pixels, assuming the text is bold
for (col = 0; col < widths.length; ++col) {
// it's ok to reuse renderer, but I chose not
// to for safety reasons. Optimize if needed.
renderer = new DataGridItemRenderer();
// Must add to datagrid as child so that it inherits
// properties essential for text width estimation,
// such as font size
dg.addChild(renderer);
dgCol = dg.columns[col] as DataGridColumn;
renderer.text = dgCol.headerText;
tf = renderer.getTextFormat();
tf.bold = true;
renderer.setTextFormat (tf);
widths[col] = Math.max(renderer.measuredWidth + 25, widths[col]);
// remove renderer from datagrid when we're done
dg.removeChild(renderer);
}
// set width of columns to determined values
for (col = 0; col < widths.length; ++col)
{
if (widths[col] != -1)
{
dg.columns[col].width = widths[col];
}
}
}
}
]]>
</mx:Script>
<mx:XMLList id="employees">
<employee>
<name>Christina Coenraets</name>
<phone>555-219-2270</phone>
<email>ccoenraets@fictitious.com</email>
<active>true</active>
</employee>
<employee>
<name>Joanne Wall</name>
<phone>555-219-2012</phone>
<email>jwall@fictitious.com</email>
<active>true</active>
</employee>
<employee>
<name>Maurice Smith</name>
<phone>555-219-2012</phone>
<email>maurice@fictitious.com</email>
<active>false</active>
</employee>
<employee>
<name>Mary Jones</name>
<phone>555-219-2000</phone>
<email>mjones@fictitious.com</email>
<active>true</active>
</employee>
</mx:XMLList>
<mx:DataGrid id="dg1" width="100%" height="100%" rowCount="5" dataProvider="{employees}" creationComplete="optimiseGridColumns(dg1)">
<mx:columns>
<mx:DataGridColumn dataField="name" headerText="Name"/>
<mx:DataGridColumn dataField="phone" headerText="Phone"/>
<mx:DataGridColumn dataField="email" headerText="Email"/>
</mx:columns>
</mx:DataGrid>
</mx:Application>
答案 3 :(得分：0)
对于Gridview控件，您可以深入查看SelectedRowStyle属性并将Wrap设置为True。