I have a web app in asp.net core mvc, I want to add data generated from database to the sidebar and footer of the website which is available in the shared layout pages, the thing that is confusing me is how can I implement this? How will be the controller
implemented? Kindly give me a hint about this. Thanks
as every controller action needs to do the lookup, you could use an attribute on the caller or action to specify the lookups required, then you middleware to do the lookup and and to the ViewBag
as every controller action needs to do the lookup, you could use an attribute on the caller or action to specify the lookups required, then you middleware to do the lookup and and to the ViewBag
I am really sorry I didn't get you, please be a bit more explicit.
I want to add data generated from database to the sidebar and footer of the website which is available in the shared layout pages
I recommend you use ViewComponent. As
Creating a view Component said, create a class whose suffix is ViewComponent,
then you can write your logic such as get data from database in it. And the component's view in some paths like '/Views/Shared/Components/{View Component Name}/{View Name} ' (you can change it depends on your needs, ways are in the tutorial).
After creating the cs and the view, you can call the ViewComponent in _Layout.cshtml by adding the following code in _Layout.cshtml:
...... @await Component.InvokeAsync("ShowDB") @*this is my component's name ,I used it as the title*@ ......
Following is my demo:
My 'ViewComponent' cs:
public class ShowDB : ViewComponent
{
private readonly MyDbContext db;
public ShowDB(MyDbContext context)
{
db = context;
}
public async Task<IViewComponentResult> InvokeAsync()
{
var items =db.MyModels
.ToList();
return View("Default",items);
}
}
ViewComponent View (named 'Default'):
@model IEnumerable<MyModel>
@foreach (var item in Model)
{
@item.Name
}
File structure:
Result:
Best Regards,
Jerry Cai
.NET forums are moving to a new home on Microsoft Q&A, we encourage you to go to Microsoft Q&A for .NET for posting new questions and get involved today.
I want to add data generated from database to the sidebar and footer of the website which is available in the shared layout pages
I recommend you use ViewComponent. As
Creating a view Component said, create a class whose suffix is ViewComponent,
then you can write your logic such as get data from database in it. And the component's view in some paths like '/Views/Shared/Components/{View Component Name}/{View Name} ' (you can change it depends on your needs, ways are in the tutorial).
After creating the cs and the view, you can call the ViewComponent in _Layout.cshtml by adding the following code in _Layout.cshtml:
......
@await Component.InvokeAsync("ShowDB") @*this is my component's name ,I used it as the title*@
......
Following is my demo:
My 'ViewComponent' cs:
publicclassShowDB:ViewComponent{privatereadonlyMyDbContext db;publicShowDB(MyDbContext context){
db = context;}public async Task<IViewComponentResult>InvokeAsync(){var items =db.MyModels.ToList();returnView("Default",items);}}
ViewComponent View (named 'Default'):
@model IEnumerable<MyModel>
@foreach (var item in Model)
{
@item.Name
}
File structure:
Result:
Best Regards,
Jerry Cai
Thank you so much Jerry! I am sure that this is the right answer. Will try it soon. Thanks again
I want to add data generated from database to the sidebar and footer of the website which is available in the shared layout pages
I recommend you use ViewComponent. As
Creating a view Component said, create a class whose suffix is ViewComponent,
then you can write your logic such as get data from database in it. And the component's view in some paths like '/Views/Shared/Components/{View Component Name}/{View Name} ' (you can change it depends on your needs, ways are in the tutorial).
After creating the cs and the view, you can call the ViewComponent in _Layout.cshtml by adding the following code in _Layout.cshtml:
......
@await Component.InvokeAsync("ShowDB") @*this is my component's name ,I used it as the title*@
......
Following is my demo:
My 'ViewComponent' cs:
publicclassShowDB:ViewComponent{privatereadonlyMyDbContext db;publicShowDB(MyDbContext context){
db = context;}public async Task<IViewComponentResult>InvokeAsync(){var items =db.MyModels.ToList();returnView("Default",items);}}
ViewComponent View (named 'Default'):
@model IEnumerable<MyModel>
@foreach (var item in Model)
{
@item.Name
}
File structure:
Result:
Best Regards,
Jerry Cai
Hello, I have a question, what if I want to add multiple components under single ViewComponent class? I want to invoke different sections of a page, let's say footer and sidebar. Is there any way to use the same class for two different components or render
different portions of layout using the same component? Thanks
If '_Layout' is your component view, why you call the '@await Component.InvokeAsync("ShowAds")' to show the component view in your component view '_Layout' again? It will cause the loop.
In summary, you can't call '@await Component.InvokeAsync("ShowAds")' in your component view.
Best Regards,
Jerry Cai
.NET forums are moving to a new home on Microsoft Q&A, we encourage you to go to Microsoft Q&A for .NET for posting new questions and get involved today.
If '_Layout' is your component view, why you call the '@await Component.InvokeAsync("ShowAds")' to show the component view in your component view '_Layout' again? It will cause the loop.
In summary, you can't call '@await Component.InvokeAsync("ShowAds")' in your component view.
Best Regards,
Jerry Cai
Sorry it was all my fault, I have edited my last post with another question, kindly check that.
.NET forums are moving to a new home on Microsoft Q&A, we encourage you to go to Microsoft Q&A for .NET for posting new questions and get involved today.
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Getting data from DB in Layout Pages
Oct 14, 2020 05:07 PM|najum98|LINK
Hello,
I have a web app in asp.net core mvc, I want to add data generated from database to the sidebar and footer of the website which is available in the shared layout pages, the thing that is confusing me is how can I implement this? How will be the controller implemented? Kindly give me a hint about this. Thanks
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Re: Getting data from DB in Layout Pages
Oct 14, 2020 06:20 PM|bruce (sqlwork.com)|LINK
as every controller action needs to do the lookup, you could use an attribute on the caller or action to specify the lookups required, then you middleware to do the lookup and and to the ViewBag
Member
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Re: Getting data from DB in Layout Pages
Oct 14, 2020 06:24 PM|najum98|LINK
I am really sorry I didn't get you, please be a bit more explicit.
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Re: Getting data from DB in Layout Pages
Oct 14, 2020 06:44 PM|mgebhard|LINK
Learn view components. View components are designed to solve this type of programming problem.
https://docs.microsoft.com/en-us/aspnet/core/mvc/views/view-components?view=aspnetcore-3.1
https://www.learnrazorpages.com/razor-pages/view-components
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Re: Getting data from DB in Layout Pages
Oct 15, 2020 06:41 AM|Jerry Cai|LINK
Hi,najum98
I recommend you use ViewComponent. As Creating a view Component said, create a class whose suffix is ViewComponent, then you can write your logic such as get data from database in it. And the component's view in some paths like '/Views/Shared/Components/{View Component Name}/{View Name} ' (you can change it depends on your needs, ways are in the tutorial).
After creating the cs and the view, you can call the ViewComponent in _Layout.cshtml by adding the following code in _Layout.cshtml:
Following is my demo:
My 'ViewComponent' cs:
public class ShowDB : ViewComponent { private readonly MyDbContext db; public ShowDB(MyDbContext context) { db = context; } public async Task<IViewComponentResult> InvokeAsync() { var items =db.MyModels .ToList(); return View("Default",items); } }ViewComponent View (named 'Default'):
@model IEnumerable<MyModel> @foreach (var item in Model) { @item.Name }File structure:
Result:
Best Regards,
Jerry Cai
Member
6 Points
50 Posts
Re: Getting data from DB in Layout Pages
Oct 15, 2020 01:45 PM|najum98|LINK
Thank you so much Jerry! I am sure that this is the right answer. Will try it soon. Thanks again
Member
6 Points
50 Posts
Re: Getting data from DB in Layout Pages
Oct 19, 2020 04:33 PM|najum98|LINK
Hello, I have a question, what if I want to add multiple components under single ViewComponent class? I want to invoke different sections of a page, let's say footer and sidebar. Is there any way to use the same class for two different components or render different portions of layout using the same component? Thanks
Participant
990 Points
327 Posts
Re: Getting data from DB in Layout Pages
Oct 20, 2020 01:37 AM|Jerry Cai|LINK
Hi, najum98
If '_Layout' is your component view, why you call the '@await Component.InvokeAsync("ShowAds")' to show the component view in your component view '_Layout' again? It will cause the loop.
In summary, you can't call '@await Component.InvokeAsync("ShowAds")' in your component view.
Best Regards,
Jerry Cai
Member
6 Points
50 Posts
Re: Getting data from DB in Layout Pages
Oct 20, 2020 01:46 AM|najum98|LINK
Sorry it was all my fault, I have edited my last post with another question, kindly check that.
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990 Points
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Re: Getting data from DB in Layout Pages
Oct 20, 2020 02:04 AM|Jerry Cai|LINK
Hi,najum98
You can give a parameter to component class like this:
public async Task<IViewComponentResult> InvokeAsync(int id) { if (id == 1) { var items = db.MyModels .ToList(); return View("_Layout", items); } var items2 = db.MyModels .ToList(); return View("Default", items2); }Then call the class with different parameter:
@await Component.InvokeAsync("ShowDB", 1) @await Component.InvokeAsync("ShowDB")Best Regards,
Jerry Cai
Member
6 Points
50 Posts
Re: Getting data from DB in Layout Pages
Oct 20, 2020 02:14 AM|najum98|LINK
Oh thank you so much again, you've been very helpful. Kudos to you