# C1.Win.C1Input.C1ComboBox.AllowPreload

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<h1 id="C1_Win_C1Input_C1ComboBox_AllowPreload_" data-uid="C1.Win.C1Input.C1ComboBox.AllowPreload*">AllowPreload Property
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<a id="C1_Win_C1Input_C1ComboBox_AllowPreload_" data-uid="C1.Win.C1Input.C1ComboBox.AllowPreload*"></a>
<h4 id="C1_Win_C1Input_C1ComboBox_AllowPreload" data-uid="C1.Win.C1Input.C1ComboBox.AllowPreload">AllowPreload</h4>
<div class="markdown level1 summary"><p>Gets or sets a value that indicates whether <a class="xref" href="C1.Win.C1Input.C1ComboBox.html">C1ComboBox</a> should preload items into the dropdown form after setting the data source.
The default value is false which means that all items will be loaded at first drop-down opening.</p>
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<h5 class="declaration">Declaration</h5>
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  <pre><code class="lang-csharp hljs">public bool AllowPreload { get; set; }</code></pre>
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  <pre><code class="lang-vbnet hljs">Public Property AllowPreload As Boolean</code></pre>
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<h5 id="C1_Win_C1Input_C1ComboBox_AllowPreload_remarks">Remarks</h5>
<div class="markdown level1 remarks"><p>Set this value to true if you want to optimize drop-down opening time for a lot of items. Keep default value if you want to optimize form loading time.
The <a class="xref" href="C1.Win.C1Input.C1ComboBox.html">C1ComboBox</a> does not support preloading items when the <a class="xref" href="C1.Win.C1Input.C1ComboBox.ItemsImageList.html#C1_Win_C1Input_C1ComboBox_ItemsImageList">ItemsImageList</a> property is set for <a class="xref" href="C1.Win.C1Input.C1ComboBox.html">C1ComboBox</a>.<br>
If you change these properties, then <a class="xref" href="C1.Win.C1Input.C1ComboBox.html">C1ComboBox</a> will clear the preloaded items: <a class="xref" href="https://learn.microsoft.com/dotnet/api/system.windows.forms.control.righttoleft">RightToLeft</a>, <a class="xref" href="C1.Win.C1Input.C1ComboBox.ItemMode.html#C1_Win_C1Input_C1ComboBox_ItemMode">ItemMode</a>, <a class="xref" href="C1.Win.C1Input.C1ComboBox.HtmlPattern.html#C1_Win_C1Input_C1ComboBox_HtmlPattern">HtmlPattern</a>,
<a class="xref" href="C1.Win.C1Input.C1ComboBox.ItemsDisplayMember.html#C1_Win_C1Input_C1ComboBox_ItemsDisplayMember">ItemsDisplayMember</a>, <a class="xref" href="C1.Win.C1Input.C1ComboBox.Style.html#C1_Win_C1Input_C1ComboBox_Style">Style</a>, <a class="xref" href="https://learn.microsoft.com/dotnet/api/system.windows.forms.combobox.dropdownwidth">DropDownWidth</a>.</p>
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