A pointer of type IDispatch indicates that the array object is actually a built-in array object of JavaScript. On the JavaScript side, we can get the size of the array through the length attribute. Then here, we can obtain the array through the GetIDsOfNames function and the Invoke function. length, so that the contents of the array can be dynamically variable.
// Get the array length
BSTR bstrLength = L "length";
DISPID dispid;
hr = lpDispatch->GetIDsOfNames(IID_NULL, &bstrLength, 1,
LOCALE_USER_DEFAULT, &dispid);
if ( SUCCEEDED(hr) )
{
CComVariant varResult;
hr = lpDispatch->Invoke(dispid, IID_NULL, LOCALE_SYSTEM_DEFAULT,
DISPATCH_PROPERTYGET, &noArgs, &varResult, NULL, NULL);
if ( varResult.vt == VT_I4 )
{
nLength = varResult.intVal;
}
}
At this time, nLength gets the length of the array.
An array in JavaScript is an object, and the contents of the array are the attributes of the object, which are dynamically created. The query method of these attributes is somewhat similar to the query method of length. They are also GetIDsOfNames and Invoke functions. The main functions are The difference lies in the name. The name of the attribute of the element object in the array is dynamically created, that is, it can be obtained through subscripting. Therefore, here, the attribute name can also be obtained through subscripting, as follows:
for ( int i=0; i
CComVariant vaIndex(i, VT_I4);
vaIndex.ChangeType(VT_BSTR);
DISPID dispid;
hr = lpDispatch->GetIDsOfNames(IID_NULL, &vaIndex.bstrVal ,1,
LOCALE_USER_DEFAULT, &dispid);
if ( FAILED(hr) )
{
continue;
}
CComVariant varResult;
hr = lpDispatch->Invoke (dispid, IID_NULL, LOCALE_SYSTEM_DEFAULT,
DISPATCH_PROPERTYGET, &noArgs, &varResult, NULL, NULL);
VARTYPE vt = varResult.vt;
if (vt == VT_DISPATCH )
{
InvokeArray( varResult );
continue;
}
hr = varResult.ChangeType(VT_BSTR);
CComBSTR bstrVal = varResult.bstrVal;
}
Therefore, by calling these two attribute methods, all JavaScript array objects can be facilitated in the COM interface.
What are the benefits of this? When looking at many online resources, I found that most of them use SAFEARRAY to process structures and pass them into the COM interface, but SAFEARRAY is not supported in MIDL, and The JavaScript object itself does not support this content. To operate in SAFEARRAY mode, you need to switch between VBScript and JavaScript. This will cause difficulties in program writing and confusion for maintenance personnel.
Directly use JavaScript to pass in the array, and integrate the array in any way. There is no need to integrate the structure through SAFEARRAY. At the same time, since every object (element) in JavaScript has its own type information, arrays in JavaScript are the best alternative (transfer method) to structures in C.

去掉重复并排序的方法:1、使用“Array.from(new Set(arr))”或者“[…new Set(arr)]”语句,去掉数组中的重复元素,返回去重后的新数组;2、利用sort()对去重数组进行排序,语法“去重数组.sort()”。

本篇文章给大家带来了关于JavaScript的相关知识,其中主要介绍了关于Symbol类型、隐藏属性及全局注册表的相关问题,包括了Symbol类型的描述、Symbol不会隐式转字符串等问题,下面一起来看一下,希望对大家有帮助。

怎么制作文字轮播与图片轮播?大家第一想到的是不是利用js,其实利用纯CSS也能实现文字轮播与图片轮播,下面来看看实现方法,希望对大家有所帮助!

本篇文章给大家带来了关于JavaScript的相关知识,其中主要介绍了关于对象的构造函数和new操作符,构造函数是所有对象的成员方法中,最早被调用的那个,下面一起来看一下吧,希望对大家有帮助。

本篇文章给大家带来了关于JavaScript的相关知识,其中主要介绍了关于面向对象的相关问题,包括了属性描述符、数据描述符、存取描述符等等内容,下面一起来看一下,希望对大家有帮助。

方法:1、利用“点击元素对象.unbind("click");”方法,该方法可以移除被选元素的事件处理程序;2、利用“点击元素对象.off("click");”方法,该方法可以移除通过on()方法添加的事件处理程序。

本篇文章给大家带来了关于JavaScript的相关知识,其中主要介绍了关于BOM操作的相关问题,包括了window对象的常见事件、JavaScript执行机制等等相关内容,下面一起来看一下,希望对大家有帮助。

foreach不是es6的方法。foreach是es3中一个遍历数组的方法,可以调用数组的每个元素,并将元素传给回调函数进行处理,语法“array.forEach(function(当前元素,索引,数组){...})”;该方法不处理空数组。


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