[cpp]  //獲得某個window的某個subView   UIView *view = [[[[[UIApplication sharedApplication] windows] objectAtIndex:0] subviews] lastObject];      NSInteger index = 0;//用來給保存的png命名   for (UIView *subView in [view subviews]) {//遍歷這個view的subViews   if ([subView isKindOfClass:NSClassFromString(@"MKMapView")]) {//找到自己需要的subView   NSLog(@"fund");   //支持retina高分的關鍵   if(UIGraphicsBeginImageContextWithOptions != NULL)   {   UIGraphicsBeginImageContextWithOptions(subView.frame.size, NO, 0.0);   } else {   UIGraphicsBeginImageContext(subView.frame.size);   }      //獲取圖像   [subView.layer renderInContext:UIGraphicsGetCurrentContext()];   UIImage *image = UIGraphicsGetImageFromCurrentImageContext();   UIGraphicsEndImageContext();      //保存圖像   NSString *path = [NSHomeDirectory() stringByAppendingFormat:@"/%d.png",index];   if ([UIImagePNGRepresentation(image) writeToFile:path atomically:YES]) {   index += 1;   NSLog(@"Succeeded! %@",path);   }   else {   NSLog(@"Failed!");   }   }   }