OS高级开发～Runtime（四）

 iOS高级开发～Runtime（一）

 iOS高级开发～Runtime（二）

 iOS高级开发～Runtime（三）

 iOS高级开发～Runtime（四）
用C代替OC：

#import <objc/runtime.h>
#import <objc/message.h>
#import <stdio.h>

extern int UIApplicationMain (int argc,char *argv[],void *principalClassName,void *delegateClassName);

struct Rect {
  float x;
  float y;
  float width;
  float height;
};
typedef struct Rect Rect;

void *navController;
static int numberOfRows =100;

int tableView_numberOfRowsInSection(void *receiver,structobjc_selector *selector,void *tblview,int
section) {
  returnnumberOfRows;
}

void *tableView_cellForRowAtIndexPath(void *receiver,structobjc_selector *selector,void *tblview,void
*indexPath) {
  Class TableViewCell = (Class)objc_getClass("UITableViewCell");
  void *cell = class_createInstance(TableViewCell,0);
  objc_msgSend(cell,
sel_registerName("init"));
  char buffer[7];
  int row = (int)
objc_msgSend(indexPath, sel_registerName("row"));
  sprintf (buffer, "Row %d", row);
  void *label =objc_msgSend(objc_getClass("NSString"),sel_registerName("stringWithUTF8String:"),buffer);
  objc_msgSend(cell,
sel_registerName("setText:"),label);
  return cell;
}

void tableView_didSelectRowAtIndexPath(void *receiver,structobjc_selector *selector,void *tblview,void
*indexPath) {
  Class ViewController = (Class)objc_getClass("UIViewController");
  void * vc = class_createInstance(ViewController,0);
  objc_msgSend(vc,
sel_registerName("init"));
  char buffer[8];
  int row = (int)
objc_msgSend(indexPath, sel_registerName("row"));
  sprintf (buffer, "Item %d", row);
  void *label =objc_msgSend(objc_getClass("NSString"),sel_registerName("stringWithUTF8String:"),buffer);
  objc_msgSend(vc,
sel_registerName("setTitle:"),label);
  objc_msgSend(navController,sel_registerName("pushViewController:animated:"),vc,1);
}

void *createDataSource() {
  Class superclass = (Class)objc_getClass("NSObject");
  Class DataSource = objc_allocateClassPair(superclass,"DataSource",0);
  class_addMethod(DataSource,sel_registerName("tableView:numberOfRowsInSection:"), (void(*))tableView_numberOfRowsInSection,nil);
  class_addMethod(DataSource,sel_registerName("tableView:cellForRowAtIndexPath:"), (void(*))tableView_cellForRowAtIndexPath,nil);
  objc_registerClassPair(DataSource);
  returnclass_createInstance(DataSource,0);
}

void * createDelegate() {
  Class superclass = (Class)objc_getClass("NSObject");
  Class DataSource = objc_allocateClassPair(superclass,"Delegate",0);
  class_addMethod(DataSource,sel_registerName("tableView:didSelectRowAtIndexPath:"), (void(*))tableView_didSelectRowAtIndexPath,nil);
  objc_registerClassPair(DataSource);
  returnclass_createInstance(DataSource,0);
}

void applicationdidFinishLaunching(void *receiver,structobjc_selector *selector,void *application) {
  Class windowClass = (Class)objc_getClass("UIWindow");
  void * windowInstance =
class_createInstance(windowClass, 0);
    
  objc_msgSend(windowInstance,
sel_registerName("initWithFrame:"),(Rect){0,0,320,480});
  
  //Make Key and Visiable
  objc_msgSend(windowInstance,sel_registerName("makeKeyAndVisible"));

  //Create Table View
  Class TableViewController = (Class)objc_getClass("UITableViewController");
  void *tableViewController =
class_createInstance(TableViewController, 0);
  objc_msgSend(tableViewController,
sel_registerName("init"));
  void *tableView = objc_msgSend(tableViewController,sel_registerName("tableView"));
  objc_msgSend(tableView,
sel_registerName("setDataSource:"),createDataSource());
  objc_msgSend(tableView,
sel_registerName("setDelegate:"),createDelegate());
 
  Class NavController = (Class)objc_getClass("UINavigationController");
  navController = class_createInstance(NavController,0);
  objc_msgSend(navController,sel_registerName("initWithRootViewController:"),tableViewController);
  void *view =objc_msgSend(navController,sel_registerName("view"));
  
  //Add Table View To Window
  objc_msgSend(windowInstance,
sel_registerName("addSubview:"),view);
}

//Create an class named "AppDelegate", and return it's name as an instance of class NSString
void *createAppDelegate() {
  Class mySubclass =
objc_allocateClassPair((Class)objc_getClass("NSObject"),"AppDelegate",0);
  structobjc_selector *selName =sel_registerName("application:didFinishLaunchingWithOptions:");
  class_addMethod(mySubclass, selName, (void(*))applicationdidFinishLaunching,nil);
  objc_registerClassPair(mySubclass);
  returnobjc_msgSend(objc_getClass("NSString"),sel_registerName("stringWithUTF8String:"),"AppDelegate");
}

int main(int argc,
char *argv[]) {
  returnUIApplicationMain(argc, argv,0,createAppDelegate());
}

运行效果：