postMessage
Post a message to the webview content.
Messages are only delivered if the webview is live (either visible or in the background with retainContextWhenHidden).
Parameters
Body of the message. This must be a string or other json serializable object.
For older versions of vscode, if an ArrayBuffer is included in message, it will not be serialized properly and will not be received by the webview. Similarly any TypedArrays, such as a Uint8Array, will be very inefficiently serialized and will also not be recreated as a typed array inside the webview.
However if your extension targets vscode 1.57+ in the engines field of its package.json, any ArrayBuffer values that appear in message will be more efficiently transferred to the webview and will also be correctly recreated inside of the webview.