How to lock a Image when running on the simulator?

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:bust_in_silhouette: Asked By mona

I really love this engine, the system and document are friendly.
I tried to create a new image and change the pixel on it, it ran well on pc and mac, but when I export it and ran on my iPhone6, it went crash. My godot engine version is 3.0.2-stable.
Here is my code.

Ref<Image> white = memnew(Image(datatextureW, datatextureH, 0, Image::FORMAT_RGB8, wt));
	datatexture = VS::get_singleton()->texture_create();
	VS::get_singleton()->texture_allocate(datatexture, datatextureW, datatextureH, Image::FORMAT_RGB8, 0);
	VS::get_singleton()->texture_set_data(datatexture, white);
	Ref<Image> white1 = VS::get_singleton()->texture_get_data(datatexture);
	white1->lock(); // went crash
	white1->unlock();

It went crash in lock() function.
Could you Please tell me how to fix it, thank you very much.