18 lines
1.6 KiB
Plaintext
18 lines
1.6 KiB
Plaintext
=== How does this work?
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Model binding in ASP.NET Core MVC and ASP.NET MVC 4.x works by automatically mapping data from HTTP requests to action method parameters. Here's a step-by-step breakdown of how it works:
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1. **Request Data** When a user submits a form or sends a request to an ASP.NET application, the request data might include form data, query string parameters, request body, and HTTP headers.
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2. **Model Binder** The model binder's job is to create .NET objects from the request data. It looks at each parameter in the action method and attempts to populate it with the incoming data.
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3. **Value Providers** The model binder uses Value Providers to get data from various parts of the request, such as the query string, form data, or route data. Each value provider tells the model binder where to find values in the request.
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4. **Binding** The model binder tries to match the keys from the incoming data with the properties of the action method's parameters. If a match is found, it attempts to convert the incoming data into the appropriate .NET type and assigns it to the parameter.
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5. **Validation** If the model binder can't convert the value or if the converted value doesn't pass any specified validation rules, it adds an error to the `ModelState.Errors` collection. You can check `ModelState.IsValid` in your action method to see if any errors occurred during model binding.
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6. **Action Method Execution** The action method is executed with the bound parameters. If `ModelState.IsValid` is `false`, you can handle the errors in your action method and return an appropriate response.
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See the links in the <<Resources>> section for more information.
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