I am learning with some small projects and I don't know, how to access XAML element from C++ code.
Can you help me please?
It says "cannot determine which instance of overloaded function is intended",
screenshot: https://pasteboard.co/JjjKCAT.png
Thank you
Lukas
When creating something in XAML, it creates two methods with the same name, one that returns that object and takes 0 arguments, and one that returns nothing (aka a void) and takes one element of that type. In your case, if you want to retrieve the value, you need to the following:
void MainWindow::Button_Click_Ring(...)
{
// Get the ProgressRing:
const auto progressRing = ProgressRing1();
// Set the ProgressRing:
ProgressRing1(newValue /* the new value */);
}
Related
What I was doing before was that I was calling a function of my interface and it determinate in a switch condition thanks to a parameter what to do with the data. What kind of specialization they have.
But now, what I am trying to create a local object, treat it, and then add it to my containers of the interface.
In order to do that I have to copy all the value of my local object (which have been treated) in my container of the interface.
So I created a copy_cell function in the interface, a virtual one, and one in the subclass. But whenever I try to do it the interface function is called and not the subfunction.
GridCell_voxel * local_cell;
local_cell = new GridCell_voxel(m_grid_map( cell2matindex_x(cell_index_x), cell2matindex_y(cell_index_y))->getVoxelResolution(), m_grid_map( cell2matindex_x(cell_index_x), cell2matindex_y(cell_index_y))->getVoxel().size());
local_cell->process_points(relevant_points, m_mapping_type);
//This is the line I need to change
local_cell->copy_cell (m_grid_map( cell2matindex_x( cell_index_x), cell2matindex_y( cell_index_y))) ;
Do you have any idea on the way to go? What am I missing here?
Sorry for the lack of information, i will try to expose how i managed and what i was actually looking for.
So i have a container of IntefaceCell, called m_grid_map, full of cell that has been specialized. In my case m_grid_map is full of GridCell_voxel which is a sub class from InterfaceCell.
What i want to do is, create a new local GridCell_voxel, copy the information in it. Then process the informations, then copy the local cell in the container.
The important part is the dynamic_cast in the copy cell function, which allow you to take an InterfaceCell as argument and then treat it as GridCell_voxel.
//Main.cpp
GridCell_voxel * local_cell;
local_cell = new GridCell_voxel();
local_cell->copy_cell (m_grid_map( cell2matindex_x( cell_index_x), cell2matindex_y( cell_index_y)));
local_cell->process_points(relevant_points, m_mapping_type);
m_grid_map( cell2matindex_x( cell_index_x), cell2matindex_y( cell_index_y))->copy_cell (local_cell);
delete local_cell;
//GridCell_voxel.cpp
void GridCell_voxel::copy_cell(GridCellInterface* cell) {
GridCell_voxel* voxel_cell = dynamic_cast<GridCell_voxel*>(cell);
this->m_voxel_start_height = voxel_cell->m_voxel_start_height;
this->init = true;
this->m_ground_voxel_position = voxel_cell->m_ground_voxel_position;
}
I hope it will help someone.
I'm confused by the difference between V8 ObjectTemplate's Set and SetAccessor methods. My question has a simple context and 4 concrete sub-questions.
Context
Let's say I have code snippet that wants to provide a global object global to the targeting JS context. global has a property x, whose value takes int value. global also has a property log, which is a function. All the snippets are taken from V8's source, process.cc and Embedder's Guide to be precise.
HandleScope handle_scope(GetIsolate());
// Create a template for the global object where we set the
// built-in global functions.
Local<ObjectTemplate> global = ObjectTemplate::New(GetIsolate());
global->Set(String::NewFromUtf8(GetIsolate(), "log",
NewStringType::kNormal).ToLocalChecked(),
FunctionTemplate::New(GetIsolate(), LogCallback));
So this code snippet provides function log to the global. Then from the Embedder's Guide to accessors, it says
An accessor is a C++ callback that calculates and returns a value when an object property is accessed by a JavaScript script. Accessors are configured through an object template, using the SetAccessor method.
The code snippet follows:
void XGetter(Local<String> property,
const PropertyCallbackInfo<Value>& info) {
info.GetReturnValue().Set(x);
}
void XSetter(Local<String> property, Local<Value> value,
const PropertyCallbackInfo<Value>& info) {
x = value->Int32Value();
}
// YGetter/YSetter are so similar they are omitted for brevity
Local<ObjectTemplate> global_templ = ObjectTemplate::New(isolate);
global_templ->SetAccessor(String::NewFromUtf8(isolate, "x"), XGetter, XSetter);
global_templ->SetAccessor(String::NewFromUtf8(isolate, "y"), YGetter, YSetter);
Persistent<Context> context = Context::New(isolate, NULL, global_templ);
As I understand this code snippet, it's providing some integer value x to the global as the description goes.
Now,from the source of V8, I see ObjectTemplate doesn't have a Set method, instead, it's inherited from parent class Template. From Template's source code, it says:
/**
* Adds a property to each instance created by this template.
*
* The property must be defined either as a primitive value, or a template.
*/
void Set(Local<Name> name, Local<Data> value,
propertyAttribute attributes = None);
Questions
Template's Set method says it can set a primitive value to the instance of the template, then can I use Set to set x in the second code snippet instead of using SetAccessor?
If the answer to question 1 is true, then what's the difference for setting x between using SetMethod and Set? Is the difference being that any modification in JS to the property set by Set will not be reflected in C++?
If the answer to question 1 is false, then why can't I use Set on X?
From the description of accessors, it says it computes and return value. So does it mean we don't use SetAccessor to return functions? I'm confused because I mainly write JS and Haskell. Both languages spoils me to take functions as values.
Now I know it should be easy to verify all my assumptions by actually building the samples, but I have difficulties compiling the V8 source, hence I'm asking for any help.
Thank you in advanced for any effort!
1. Yes.
2. Set is the C++ equivalent (modulo property attributes) of:
Object.defineProperty(global, "x", {value: 3})
SetAccessor is the C++ equivalent of:
Object.defineProperty(global, "x", {get: function XGetter() { return ...; },
set: function XSetter(val) { ... }});
As you suggest, a consequence is that in case of Set, the C++ side has no way of knowing whether the value was changed from the JavaScript side.
3. n/a
4. The getter can return any value you want; in particular the value can be a function.
I'm trying to copy a range of Excel cells between two different sheets using Excel automation via C++. I am using excel8.cpp to interface with Excel.
I want to call the Range.Copy method but I'm not sure how exactly to pass the destination parameter. I think this is the correct way:
//ranges already defined
//XL::Range range1, range2;
COleVariant myVar;
VariantInit(myVar);
myVar.vt = VT_DISPATCH;
myVar.pdispVal = (LPDISPATCH)range2;
range1.Copy(myVar);
However when I try this, I get the message "Copy method of Range class failed".
Also, I don't want to pass an optional Variant into the copy function because there is a bug I have come across with the clipboard causing Copy and Paste to fail randomly.
I have a web service that sends a struct to a client program.
I need to pass an arraylist of string values as one of the properties of this struct, but by the time it gets to the client program its type is 'object'. Once it gets back to the client program, how can I convert this Object datatype back into the arraylist?
Unless you're stuck at .NET 1.1, don't use ArrayList. Try returning a List<YourStruct> instead.
The problem was the way I was attempting to explicitly create an arraylist and then setting it equal to the returned property from the struct; here's the correct way to do it - some weird VB implicit thingy. (sorry, never drank the VB kool-aid)
Dim ReturnedArrList As New ArrayList(structReturned.arrReturnedArrayList)
Hi I have just started using C++ today, and I am working on checkboxes. I have tried using CheckBox1->Checked in an if statement or whatever, but it isn't working.
The error is:
Error 2 error C2227: left of '->Checked' must point to class/struct/union/generic type
EDIT: The Code is:
void function ()
{
if (1001->Checked)
{
Sleep(2000);
}
}
Without seeing some of your code, it's very difficult to offer targeted assistance.
However, that error message usually comes about because the item you're de-referencing is not a pointer.
Check to ensure it's of the correct type. It should be something along the lines of:
tCheckBox *CheckBox1;
One possibility is that you've declared it not as a pointer to the checkbox but as a checkbox itself:
tCheckBox CheckBox1;
Note the lack of the asterisk there that would otherwise mark it as a pointer. In that case, you would use CheckBox1.Checked rather than CheckBox1->Checked, if it's allowed by the framework (this isn't standard C++ since that beast has no concept of GUI libraries).
If that doesn't help, please post the code so we can offer better suggestions.
Update:
if (1001->Checked) ?????
1001 is not a pointer - it's not a variable of any description, it's an integer constant.
You need to declare and use a variable of some description. First step is, I think, to read up on the documentation for your framework and/or get some sample code that does compile and work, basing your initial work of that.
Use CButton::GetCheck() to determine the state of the checkbox - like so...
CButton* pButton = (CButton*) GetDlgItem(IDC_CHECKBOX_RESOURCE_ID);
if ( BST_CHECKED == pButton->GetCheck() )
{
// button is checked
}