elem

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: I am trying to instantiate new HTMLDivElement in TypeScript var elem = new HTMLDivElement(); but the browser throws Uncaught TypeError: Illegal constructor. The workaround seems to be to use var elem = document.createElement('div'); but I find this suboptimal for various reasons. Why can't I instantiate DOM elements directly when there is a new keyword for in in the lib.d.ts ? declare var HTMLDivElement: { prototype: HTMLDivElement; new (): HTMLDivElement; } 回答1: Note that the error you get here is "Illegal constructor". This is different

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: I need to download a file to a given location on a non-local machine. This is the normal flow of the web browser for which I would do this: Go to website Click button to download file (it is a form that generates the file, it is not a download link) The website prompts an alert window "Do you want to download this file?", etc. I want to be able to bypass the file and do something like: >>> path_to_download_path = PATH >>> button = driver.find_element_by_css("...") >>> button.click() --> And the file is automatically downloaded to my PATH (or

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: I'm trying to learn how to use openCV's new c++ interface. How do I access elements of a multi channel matrix. for example: Mat myMat(size(3, 3), CV_32FC2); for (int i = 0; i What is the easiest way to do this? Something like cvSet2D of the old interface What is the most efficiant way? Similar to using direct pointers in the old interface. Thank you 回答1: typedef struct elem_ { float f1; float f2; } elem; elem data[9] = { 0.0f }; CvMat mat = cvMat(3, 3, CV_32FC2, data ); float f1 = CV_MAT_ELEM(mat, elem, row, col).f1; float f2 = CV_MAT_ELEM

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: I'm studying sys/queue.h from FreeBSD and I have one question: In sys/queue.h , LIST_ENTRY is defined as follows: #define LIST_ENTRY(type) \ struct { \ struct type *le_next; /* next element */ \ struct type **le_prev; /* address of previous next element */ \ } Why does it maintain the address of previous next element ( struct type **le_prev ) rather than simply previous elment like struct type *le_prev ? 回答1: If you would have read the queue.h file from the beginning, you may have got following comment: * A list is headed by a single forward

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: I have been having some trouble using Protractor. I have a really weird ui-router state where its hard to go off of other elements to start working with the page. Is there any way to tell protractor to wait until an element finally appears in the DOM? Not visible/displayed, but actually created? I keep trying to use wait for the element but it is clearly not available to be selected. browser.driver.wait(function () { return elem.isDisplayed(); }); 回答1: You should be able to use browser.wait together with the presenceOf ExpectedCondition :

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: I'm trying to learn how to use openCV's new c++ interface. How do I access elements of a multi channel matrix. for example: Mat myMat(size(3, 3), CV_32FC2); for (int i = 0; i < 3; ++i) { for (int j = 0; j < 3; ++j) { //myMat_at_(i,j) = (i,j); } } What is the easiest way to do this? Something like cvSet2D of the old interface What is the most efficiant way? Similar to using direct pointers in the old interface. Thank you 回答1: typedef struct elem_ { float f1; float f2; } elem; elem data[9] = { 0.0f }; CvMat mat = cvMat(3, 3, CV_32FC2, data );

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: How do I make a textbox that has a grayed out content, and when I click on it to enter text, the grayed out portion, it disappears and allows me to enter the desired text? Example: A "First Name" text box. The words "First Name" are inside the text box grayed out, when I click, those words disappear and I write my name in it. 回答1: This answer illustrates a pre-HTML5 approach. Please take a look at Psytronic's answer for a modern solution using the placeholder attribute. HTML: JavaScript: function inputFocus(i) { if (i.value == i.defaultValue

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: I have such a piece of code from this question : def addChild(n: Node, newChild: Node) = n match { case Elem(prefix, label, attribs, scope, child @ _*) => Elem(prefix, label, attribs, scope, child ++ newChild : _*) case _ => error("Can only add children to elements!") } Everything in it is pretty clear, except this piece: child ++ newChild : _* What does it do? I under stand there is Seq[Node] concatenated with another Node, and then? What does : _* do? 回答1: It "splats" 1 the sequence. Look at the constructor signature new Elem(prefix:

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: import xml.etree.ElementTree as ET e = ET.Element('Brock',Role="Bodyguard") print bool(e) Why is an xml.etree.ElementTree.Element considered False ? I know that I can do if e is not None to check for existence. But I would strongly expect bool(e) to return True . 回答1: As it turns out, Element objects are considered a False value if they have no children. I found this in the source: def __nonzero__(self): warnings.warn( "The behavior of this method will change in future versions. " "Use specific 'len(elem)' or 'elem is not None' test instead.

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: I am using jQuery Uniform to style inputs/selects etcs. However, the checkbox has stopped working. I am appending data sent from an ajax call. Once it's loaded, I use $.uniform.update("input:checkbox") to update the new html. When attempting to (un)check the input it works only once. If I want to (un)check it again, it doesn't change at all. I've attempted changing the Uniform Javascript so that all the actions (ie. click , focus , blur etc) are under the .live function. (ie. .live("click", ). This just stops anything from working. Update: I