如何在objc_msgSend()中将直接字符串作为参数传递？

Question

我试图使用ios.And中的c语言做一个简单的例子，我编写了下面的代码来表示一个view.It是工作的fine.But，问题是我想将直接文本传递给我创建了对象的UILabel。

BOOL AppDel_didFinishLaunching(struct AppDel *self, SEL _cmd, void *application, void *options)
{
    self->window = objc_msgSend(objc_getClass("UIWindow"), sel_getUid("alloc"));
    self->window = objc_msgSend(self->window, sel_getUid("initWithFrame:"), (struct CGRect) { 0, 0, 320, 480 });

    id viewController = objc_msgSend(objc_msgSend(objc_getClass("UIViewController"), sel_getUid("alloc")), sel_getUid("init"));

    id view = objc_msgSend(objc_msgSend(objc_getClass("View"), sel_getUid("alloc")), sel_getUid("initWithFrame:"), (struct CGRect) { 0, 0, 320, 480 });

    id label=objc_msgSend(objc_msgSend(objc_getClass("UILabel"), sel_getUid("alloc")), sel_getUid("initWithFrame:"),(struct CGRect){20,20,200,30});
    objc_msgSend(label, sel_getUid("setBackgroundColor:"),objc_msgSend(objc_getClass("UIColor"), sel_getUid("greenColor")));

    objc_msgSend(label, sel_getUid("setText:"),?); //here how to set text by direct string?

    objc_msgSend(view, sel_getUid("addSubview:"),label);
    objc_msgSend(objc_msgSend(viewController, sel_getUid("view")), sel_getUid("addSubview:"), view);
    objc_msgSend(self->window, sel_getUid("setRootViewController:"), viewController);
    objc_msgSend(self->window, sel_getUid("makeKeyAndVisible"));

    return YES;
}

objc_msgSend(标签，sel_getUid("setText:")，?)；//在这一行中，我必须传递字符串.

你知不知道？谢谢！

Answer 1

objc_msgSend(label, sel_getUid("setText:"),CFSTR("This is my string."));