parent-child

问题 I'm trying to use the php function method_exists, but I need to check if the method exists in the parent class of an object. so: class Parent { public function myFunction() { /* ... */ } } class Child extends Parent { /* ... */ } $myChild = new Child(); if (method_exists($myChild, 'myFunction')) { /* ... */ } if (method_exists(Parent, 'myFunction')) { /* ... */ } if (is_callable(array('Parent', 'myFunction')) { /* ... */ } But none of the above are working. I'm not sure what to try next.

问题 I have a div containing several other divs containing an image. It looks smth like this <div id="parentHldr"> <div class="imgHldr"><img src="foo/bar.png" id="1"></div> <div class="imgHldr"><img src="foo/bar.png" id="2"></div> <div class="imgHldr"><img src="foo/bar.png" id="3"></div> <div class="imgHldr active"<img src="foo/bar.png" id="4"></div> <div class="imgHldr"><img src="foo/bar.png" id="5"></div> <div class="imgHldr"><img src="foo/bar.png" id="6"></div> </div> I want to know the

问题 In the below example, I'm trying to count the number of drinks I can make based on the availability of ingredients per bar location that I have. To further clarify, as seen in the below example: based on the figures highlighted in the chart below; I know that I can only make 1 Margarita on 6/30/2018 (in either DC or FL if I ship the supplies to the location). Sample of data table Please use the below code to enter the relevant data above: CREATE TABLE #drinks ( a_date DATE, loc NVARCHAR(2),

问题 a React newbie having some issues passing down states and functions from Parent Component ( App in this case) and accessing from Child Components ( Main in this case). I'm sure it's one or two really simple mistakes, where am I getting tripped up? Here is the project structure: App |__ Rootstack | |__Favorites |__Main And here is the stripped down code: class Main extends React.Component { render() { return ( <View> <Text>{this.props.favoritesList.length}</Text> <Card> onSwiped={() => {this

问题 Ok so complete rewrite of the question due to lack of replies. I want a window that is drag-able but as it's being dragged, alter the margin to extend as far as the old position of the window. I.e. Window moves right X, extend margin left X. Now I've hit a few snags such as the window having it's edges cut off for some reason. Here's my code, let me know if you can spot anything! private void Window_LocationChanged(object sender, EventArgs e) { double TmpLeft = Math.Abs(this.Left - WinLeft);

问题 I need help with a problem regarding data saved in a parent-children model table and a report I need to build upon it. I've already tried searching for topics about parent-children issues, but I couldn't find anything useful in my scenario. What I have A Microsoft SQL Server 2000 database server. A categories table, which has four columns: category_id , category_name , father_id and visible ; the categories have x root categories (where x is variable), and could be y level deep (where y is

问题 If possible, can I click on an element in an iframe and have that perform a function on the page it is rendered on? for example: <div class="page"> <iframe class="frame">[... the source will render: <div class="clickme"></div>...] </iframe> ...meanwhile, back on the main page... <script> $(".clickme").click(function(){ alert('clicked'); }); </script> </div> edit also, I forgot to mention that the iframe's src changes after the page loads, this could be an obstacle! It doesn't seem to work for

问题 Lets say that i have two entities public class EntityA { @id @GeneratedValue @Column(name="id") private Long id; @OneToMany(mappedBy="EntityA") @JoinColumn(name = "entityA_id") private List<EntityB> entityBList; } public class EntityB { @Column(name = "MODEL_PERCENT") private BigDecimal modelPercent; @ManyToOne @joincolumn(name="entityA_id") private EntityA entityA; } What i want now is, when i fetch the EntityA i want to add a where clause to fetch all EntityBs' whose modelPercent is greater

问题 I have this problem: Given a number of arrays (for example in Perl, or any other language): 1. (A,B,C) 2. (B,D,E,F) 3. (C,H,G) 4. (G,H) In each array, the first element is the parent, the rest are its children. In this case, element A has two children B and C, and B has three children D, E, and F, etc. I would like to process this set of arrays, and generate a list which contains the correct order. In this case, A is the root element, so comes B and C, then under B is D, E and F, and under C

问题 I have a structure that looks like the one below, I'm trying to get the id foo . It is the only DIV with id if we bubble up from the onclick func() , which means that there wont be other DIVs that contain an id inside foo . However, there can be other tags inside foo that contain an id (such as bye, hello ). No frameworks are being used. <div id="bar"></div> <div id="foo"> <p><p> <div class="bye"> <input id="bye" type="text" value="test" /> <input id="hello" type="text" value="test" /> <table