IsNull Property (HtmlElement)

Gets a value that indicates whether or not the value of the html element is null value.

Syntax

public bool IsNull {get;}

Property Value

Type: System.Boolean
true if the html element value is null, otherwise false.

Example

The following code example uses the IsNull property.

public static int Execute(Instance instance, IZennoPosterProjectModel project)
{
    // clear cookie
    instance.ClearCookie();
    
    // go to lessons.zennolab.com
    Tab tab = instance.MainTab;
    if ((tab.IsVoid) || (tab.IsNull)) return -1;
    if (tab.IsBusy) tab.WaitDownloading();
    tab.Navigate("lessons.zennolab.com");
    if (tab.IsBusy) tab.WaitDownloading();
    
    // find element by attribute
    HtmlElement he = tab.GetDocumentByAddress("0").FindElementByAttribute("input:checkbox", "fulltag", "input:checkbox", "text", 0);
    
    // if element is null then return -1
    if (he.IsNull) return -1;
    
    return 0;
}

public static function Execute($instance, $project)
{
    // clear cookie
    $instance->ClearCookie();
    
    // go to lessons.zennolab.com
    $tab = $instance->MainTab;
    if (($tab->IsVoid) || ($tab->IsNull)) return -1;
    if ($tab->IsBusy) $tab->WaitDownloading();
    $tab->Navigate("lessons.zennolab.com");
    if ($tab->IsBusy) $tab.->WaitDownloading();
    
    // find element by attribute
    $he = $tab->GetDocumentByAddress("0")->FindElementByAttribute("input:checkbox", "fulltag", "input:checkbox", "text", 0);
    
    // if element is null then return -1
    if ($he->IsNull) return -1;
    
    return 0;
}

Requirements

Target Platforms: Desktop: Windows XP SP3 and older. Server: Windows Server 2003 and older.

Reference

HtmlElement Class
HtmlElement Members
ErrorDetected Property
IsVoid Property