C函数调用的目标C函数 [英] C function calling objective C functions

问题描述

我在我的viewController.m C函数。

I've a c function in my viewController.m.

int abc(int a, char* b)
{
//do something
}

我也有一个函数

-(void) callIncomingClass
{
    UIButton *button = [UIButton buttonWithType:UIButtonTypeRoundedRect];

    //set the position of the button
    button.frame = CGRectMake(100, 170, 100, 30);

    //set the button's title
    [button setTitle:@"Click Me!" forState:UIControlStateNormal];

    //add the button to the view
    [self.view addSubview:button];
}

现在我想从现在的功能ABC内调用 callIncomingClass 。

Now I want to call callIncomingClass from within the function abc now.

你怎么建议我去了解它？

How do you suggest I go about it??

为什么我要打电话从C功能的目标C的方法是，我已经不能创建一个按钮或做一些处理一样，在C函数。

Why I want to call an Objective C method from the C function is, I've cannot create a button or do some processing like that in the C function.

应在下述code的工作：

Should the following code work :

int abc(int a, char* b)
{ 
    ViewController * tempObj = [[ViewController alloc] init];
    [tempObj callIncomingClass];
}

编辑：我在做什么大图片
有一个C库，即一个LIBRARY.C和library.h文件。该library.h文件中有一个具有回调函数的结构。这些都需要与函数指针分配。所以，我的签名INT ABC（INT，CHAR *），它是要分配给在结构中的回调函数的C函数。

edit : the big picture of what I am doing There is a c library, i.e. a library.c and library.h file. The library.h file has a struct that has callback functions. These need to be assigned with function pointers. so I've a c function with the signature int abc(int,char*) that is to be assigned to the callback function in the struct.

此功能ABC在ViewController.m定义。
理想的情况是我希望它在一个单独的文件中定义。不过这也是奥基。

This function abc is defined in ViewController.m. Ideally i wanted it to be defined in a separate file. but this is also okie.

所以，现在，回调事件发生，我想创建一个UIButton上查看一些动作。由于我无法从C函数创建一个UIButton，我调用的ViewController类的客观C法，即创建的UIButton。

So now, the callback event happens, I want to create a UIButton with some action on the View. As I can't create a UIButton from a c function, i am calling a objective C method of the ViewController class, that creates the UIButton.

。希望清除图片为我计划如何使用这一点。

Hope that clears the picture as to how I am planning to use this.

推荐答案

您按钮不会显示，因为别人和自己都在说：你需要的的ViewController 。您正在创建的ViewController，这是从来没有带来在屏幕上或推一个全新的实例等。

Your button doesn't show because of what others and myself were saying: you need the existing instance of the ViewController. You are creating an entirely new instance of the ViewController, which is never brought on screen or pushed, etc.

您可以完成你需要使用一个指向现有实例一个全局变量做什么。

You can accomplish what you need to do by using a global variable that points to your existing instance.

下面是您的m应该是什么样子：

Here's what your .m should look like:

#import "ViewController.h"

static ViewController *viewController = nil;

@implementation ViewController

- (id)init {
    if ((self = [super init])) {
         viewController = self;
    }
    return self;
}

- (void)dealloc {
    viewController = nil;
}

-(void) callIncomingCreateButton {
    UIButton *button = [UIButton buttonWithType:UIButtonTypeRoundedRect];
    //set the position of the button
    button.frame = CGRectMake(100, 170, 100, 30);
    //set the button's title
    [button setTitle:@"Click Me!" forState:UIControlStateNormal];
    //add the button to the view
    [self.view addSubview:button];
}

- (IBAction)DemoCall:(id)sender {
    callIncoming(1, "a");
}

@end

int callIncoming(int a, char* b) {
    [viewController callIncomingCreateButton];
    return a;
}

这篇关于C函数调用的目标C函数的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！