###### (This is the legacy documentation for SDL2, the previous stable version; [SDL3](https://wiki.libsdl.org/SDL3/) is the current stable version.) # SDL_ShowMessageBox Create a modal message box. ## Header File Defined in [SDL_messagebox.h](https://github.com/libsdl-org/SDL/blob/SDL2/include/SDL_messagebox.h) ## Syntax ```c int SDL_ShowMessageBox(const SDL_MessageBoxData *messageboxdata, int *buttonid); ``` ## Function Parameters | | | | | ------------------------------------------------ | ------------------ | ------------------------------------------------------------------------------------------ | | const [SDL_MessageBoxData](SDL_MessageBoxData) * | **messageboxdata** | the [SDL_MessageBoxData](SDL_MessageBoxData) structure with title, text and other options. | | int * | **buttonid** | the pointer to which user id of hit button should be copied. | ## Return Value (int) Returns 0 on success or a negative error code on failure; call [SDL_GetError](SDL_GetError)() for more information. ## Remarks If your needs aren't complex, it might be easier to use [SDL_ShowSimpleMessageBox](SDL_ShowSimpleMessageBox). This function should be called on the thread that created the parent window, or on the main thread if the messagebox has no parent. It will block execution of that thread until the user clicks a button or closes the messagebox. This function may be called at any time, even before [SDL_Init](SDL_Init)(). This makes it useful for reporting errors like a failure to create a renderer or OpenGL context. On X11, SDL rolls its own dialog box with X11 primitives instead of a formal toolkit like GTK+ or Qt. Note that if [SDL_Init](SDL_Init)() would fail because there isn't any available video target, this function is likely to fail for the same reasons. If this is a concern, check the return value from this function and fall back to writing to stderr if you can. ## Version This function is available since SDL 2.0.0. ## See Also - [SDL_ShowSimpleMessageBox](SDL_ShowSimpleMessageBox) ---- [CategoryAPI](CategoryAPI), [CategoryAPIFunction](CategoryAPIFunction), [CategoryMessagebox](CategoryMessagebox)