How to return value to Objective-C using DLLImport (hiding UIWebView inputAccessoryView)

Asked Sep 06 '16 at 19:29

Active Sep 06 '16 at 19:29

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How to return nil value to Objective-C using DLLImport and MonoPInvokeCallback. I'm trying to implement this solution iOS 7 UIWebView keyboard issue in Xamarin.iOs I'm able to get callback using this approach How to port "method_getImplementation" and "method_setImplementation" to MonoTouch?

I'm trying something like this. Delegate is called but IntPtr.Zero value isn't returned to Objective-c.

delegate IntPtr CaptureDelegate(IntPtr block, IntPtr self, IntPtr uiView);

[MonoPInvokeCallback(typeof (CaptureDelegate))]
static IntPtr MyCapture(IntPtr block, IntPtr self, IntPtr uiView)
{            
    return IntPtr.Zero;
}
public void SetImplementation(UIView subview)
{
    var method = class_getInstanceMethod(subview.ClassHandle, new Selector("inputAccessoryView").Handle);
    var block_value = new BlockLiteral();
    block_value.SetupBlock(MyCapture, null); 
    class_addMethod(subview.ClassHandle, new Selector("inputAccessoryView").Handle, imp_implementationWithBlock(ref block_value), IntPtr.Zero);
}

How to return nil to obj-c?

edited May 23 '17 at 12:01

Community

asked Sep 06 '16 at 19:29

Ostap

IntPtr.Zero is not a `null`, just return `null` i.e, `return null;` and set the return type of your method to `IntPtr?`. – SushiHangover Sep 06 '16 at 19:41
@SushiHangover Return type is IntPtr. But IntPtr is value type so I cannot return null – Ostap Sep 07 '16 at 10:14
Make it nullable (`IntPtr?`) – SushiHangover Sep 07 '16 at 10:15
doesn't work :( – Ostap Sep 07 '16 at 12:46

How to return value to Objective-C using DLLImport (hiding UIWebView inputAccessoryView)

0 Answers0