如何在Xamarin.Forms中编写跨平台差异化代码并调用第三方SDK？

Got it, let's walk through each part of your question clearly—integrating platform-specific SDKs and triggering them from a shared Xamarin.Forms button is a common scenario, so here's how to do it right:

You have two primary approaches depending on how complex the JAR is:

Option 1: Embed the JAR Directly (Simple SDKs) #

• Drop your JAR file into a folder (like Libs) in your Xamarin.Android project.
• Right-click the JAR → Properties → Set Build Action to EmbeddedJar.
• Clean and rebuild your project—Xamarin will automatically generate C# bindings for the JAR's classes/methods.

Option 2: Use a Binding Library (Complex SDKs) #

If the JAR has conflicting names, hidden members, or requires custom bindings:

• Create a new Xamarin.Android Binding Library project in your solution.
• Place the JAR in the project's Jars folder, then set its Build Action to InputJar.
• Edit the Metadata.xml file to tweak bindings (e.g., rename classes, remove unsupported members).
• Build the binding library, then add a reference to it in your main Xamarin.Android project.

iOS SDKs come in two main formats—here's how to handle both:

For .framework Packages #

• Drag the .framework folder directly into your Xamarin.iOS project.
• Right-click the framework → Properties → Set Build Action to NativeReference.
• If the SDK requires additional linker flags, add them in your project's iOS Build settings under Additional mtouch arguments.

For .a Static Libraries #

• Drag the .a file into your Xamarin.iOS project, set its Build Action to NativeReference.
• If the SDK includes header files, create a Xamarin.iOS Binding Library project:
  1. Add the .a file and header files to the binding project.
  2. Edit ApiDefinition.cs and StructsAndEnums.cs to map native Objective-C APIs to C#.
  3. Build the binding library and reference it in your main Xamarin.iOS project.

The cleanest way to handle this is with Xamarin's Dependency Service, which lets you call platform-specific code from the shared project:

Step 1: Define a Shared Interface #

In your Xamarin.Forms shared project, create an interface for the SDK action:

public interface IThirdPartySdkHandler
{
    void InvokeSdkApi();
    // Add parameters here if you need to pass data to the SDK, e.g.:
    // void InvokeSdkApi(string userData);
}

Step 2: Implement the Interface on Android #

In your Xamarin.Android project, add the implementation and register it with Dependency Service:

[assembly: Dependency(typeof(ThirdPartySdkHandler_Android))]
namespace YourAppName.Droid
{
    public class ThirdPartySdkHandler_Android : IThirdPartySdkHandler
    {
        public void InvokeSdkApi()
        {
            // Replace this with your actual Android SDK call
            // Example: ThirdPartyAndroidSdk.PerformAction();
        }
    }
}

Step 3: Implement the Interface on iOS #

In your Xamarin.iOS project, do the same:

[assembly: Dependency(typeof(ThirdPartySdkHandler_iOS))]
namespace YourAppName.iOS
{
    public class ThirdPartySdkHandler_iOS : IThirdPartySdkHandler
    {
        public void InvokeSdkApi()
        {
            // Replace this with your actual iOS SDK call
            // Example: ThirdPartyIOSSDK.PerformAction();
        }
    }
}

Step 4: Hook Up the Button Click #

In your Xamarin.Forms page (XAML or code-behind), add the click event handler that calls the platform-specific code:

private void OnSdkButtonClicked(object sender, EventArgs e)
{
    var sdkHandler = DependencyService.Get<IThirdPartySdkHandler>();
    sdkHandler?.InvokeSdkApi();
}

If you're using XAML, just wire the event to the handler:

<Button Text="Call SDK" Clicked="OnSdkButtonClicked" />

内容的提问来源于stack exchange，提问作者YuKeung