当前位置：文江博客知识库 en-US 文档 Mozilla Projects SpiderMonkey JSAPI_reference JS_GetInstancePrivate

JS_GetInstancePrivate 编辑

Retrieve the private data associated with an object, if that object is an instance of a specified class.

Syntax

void *
JS_GetInstancePrivate(JSContext *cx, JS::Handle<JSObject*> obj,
                      const JSClass *clasp, JS::CallArgs *args); // Added in JSAPI 32

void *
JS_GetInstancePrivate(JSContext *cx, JS::Handle<JSObject*> obj,
                      const JSClass *clasp, jsval *argv); // Obsolete since JSAPI 32

Name	Type	Description
`cx`	`JSContext *`	A context.
`obj`	`JS::Handle<JSObject*>`	The object for which to retrieve private data.
`clasp`	`JSClass *`	Class against which to test the object.
`args`	`JS::CallArgs *`	Optional argument, used for error reporting. Added in SpiderMonkey 32
`argv`	`jsval *`	Optional argument vector, used for error reporting. Obsolete since JSAPI 32 This must be one of the following: an `argv` pointer created by the JavaScript engine and passed to a `JSNative` callback; `JS_ARGV(cx, vp)` where `vp` is a pointer created by the engine and passed to a `JSFastNative` callback; or `NULL`.

JS_GetInstancePrivate determines if a JavaScript object, obj, is an instance of a given JSClass, clasp, and if it is, returns a pointer to the object's private data. Otherwise it returns NULL.

Note that if obj is an instance of clasp, but there is no private data currently associated with the object, or the object cannot have private data, JS_GetInstancePrivate also returns NULL.

If you pass a non-null argument vector, argv, to JS_GetInstancePrivate, and obj is not an instance of clasp, this function reports a class mismatch error before returning NULL. In this case, JS_GetInstancePrivate tests whether or not there is a function name associated with the argument vector, and if there is, reports the name in an error message using the JS_ReportError function.

JS_GetInstancePrivate 编辑

Syntax

Description

See Also

如果你对这篇内容有疑问，欢迎到本站社区发帖提问参与讨论，获取更多帮助，或者扫码二维码加入 Web 技术交流群。

发布评论

词条统计

友情链接

JS_GetInstancePrivate 编辑

Syntax

Description

See Also

如果你对这篇内容有疑问，欢迎到本站社区发帖提问 参与讨论，获取更多帮助，或者扫码二维码加入 Web 技术交流群。

发布评论

词条统计

友情链接

如果你对这篇内容有疑问，欢迎到本站社区发帖提问参与讨论，获取更多帮助，或者扫码二维码加入 Web 技术交流群。