泰安做网站哪里好,网页设计主要做什么,装饰设计公司起名,ppt网站源码案例#xff1a;开源中国iOS客户端 当我们新建一个工程的时候#xff0c;在Supporting FIles文件下会看到一个以 -Prefix.pch结尾文件的文件#xff0c;pch全称是“precompiled header”#xff0c;也就是预编译头文件#xff0c;该文件里存放的工程中一些不常被修…案例开源中国iOS客户端 当我们新建一个工程的时候在Supporting FIles文件下会看到一个以 -Prefix.pch结尾文件的文件pch全称是“precompiled header”也就是预编译头文件该文件里存放的工程中一些不常被修改的代码比如常用的框架头文件这样做的目的提高编译器编译速度。我们知道当我们修改一个工程中某个文件代码时候编译器并不是重新编译所有所有文件而是编译改动过文件的假如pch中某个文件修改了那么pch整个文件里包含的的其他文件也会重新编译一次这样就会消耗大量时间所以它里面添加的文件最好是是很少变动或不变动的头文件或者是预编译的代码片段在新建一个工程时pch后缀文件里代码是 #import Availability.h #ifndef __IPHONE_4_0#warning This project uses features only available in iOS SDK 4.0 and later.#endif #ifdef __OBJC__ #import UIKit/UIKit.h #import Foundation/Foundation.h#endif 复制代码 或许你会觉得这预编译代码很少但是你可以查看一下UIKit.h的定义文件中 //// UIKit.h// UIKit//// Copyright (c) 2005-2011, Apple Inc. All rights reserved.// #import UIKit/UIKitDefines.h#import UIKit/UIAccelerometer.h#import UIKit/UIAccessibility.h #import UIKit/UIActivityIndicatorView.h#import UIKit/UIAlert.h#import UIKit/UIApplication.h#import UIKit/UIBarButtonItem.h#import UIKit/UIBarItem.h#import UIKit/UIBezierPath.h#import UIKit/UIButton.h#import UIKit/UIColor.h#import UIKit/UIControl.h#import UIKit/UIDataDetectors.h#import UIKit/UIDatePicker.h#import UIKit/UIDevice.h#import UIKit/UIDocument.h#import UIKit/UIDocumentInteractionController.h#import UIKit/UIEvent.h#import UIKit/UIFont.h#import UIKit/UIGeometry.h#import UIKit/UIGestureRecognizer.h#import UIKit/UIGraphics.h#import UIKit/UIImage.h#import UIKit/UIImagePickerController.h#import UIKit/UIImageView.h#import UIKit/UIInterface.h#import UIKit/UILabel.h#import UIKit/UILocalNotification.h#import UIKit/UILocalizedIndexedCollation.h#import UIKit/UILongPressGestureRecognizer.h#import UIKit/UIManagedDocument.h#import UIKit/UIMenuController.h#import UIKit/UINavigationBar.h#import UIKit/UINavigationController.h#import UIKit/UINib.h#import UIKit/UINibDeclarations.h#import UIKit/UINibLoading.h#import UIKit/UIPageControl.h#import UIKit/UIPageViewController.h#import UIKit/UIPanGestureRecognizer.h#import UIKit/UIPasteboard.h#import UIKit/UIPickerView.h#import UIKit/UIPinchGestureRecognizer.h#import UIKit/UIPopoverController.h#import UIKit/UIPopoverBackgroundView.h#import UIKit/UIPrintError.h#import UIKit/UIPrintFormatter.h#import UIKit/UIPrintInfo.h#import UIKit/UIPrintInteractionController.h#import UIKit/UIPrintPageRenderer.h#import UIKit/UIPrintPaper.h#import UIKit/UIProgressView.h#import UIKit/UIReferenceLibraryViewController.h#import UIKit/UIResponder.h#import UIKit/UIRotationGestureRecognizer.h#import UIKit/UIScreen.h#import UIKit/UIScreenMode.h#import UIKit/UIScrollView.h#import UIKit/UISearchBar.h#import UIKit/UISearchDisplayController.h#import UIKit/UISegmentedControl.h#import UIKit/UISlider.h#import UIKit/UISplitViewController.h#import UIKit/UIStepper.h#import UIKit/UIStoryboard.h#import UIKit/UIStoryboardPopoverSegue.h#import UIKit/UIStoryboardSegue.h#import UIKit/UIStringDrawing.h#import UIKit/UISwipeGestureRecognizer.h#import UIKit/UISwitch.h#import UIKit/UITabBar.h#import UIKit/UITabBarController.h#import UIKit/UITabBarItem.h#import UIKit/UITableView.h#import UIKit/UITableViewCell.h#import UIKit/UITableViewController.h#import UIKit/UITapGestureRecognizer.h#import UIKit/UITextField.h#import UIKit/UITextInput.h#import UIKit/UITextInputTraits.h#import UIKit/UITextView.h#import UIKit/UIToolbar.h#import UIKit/UITouch.h#import UIKit/UIVideoEditorController.h#import UIKit/UIView.h#import UIKit/UIViewController.h#import UIKit/UIWebView.h#import UIKit/UIWindow.h 复制代码 这些不少了吧工程每次运行都编译是不是很费时间这些是苹果公司内部定义的标准头文件我们不能也没有权限修改这些头文件定义内容所以当放到pch文件中会加速编译过程再来看看我们开源中国iOS客户端pch文件 //// Prefix header for all source files of the oschina target in the oschina project// #import Availability.h #ifndef __IPHONE_4_0#warning This project uses features only available in iOS SDK 4.0 and later.#endif #ifdef __OBJC__ #import UIKit/UIKit.h #import Foundation/Foundation.h #import CoreData/CoreData.h #import QuartzCore/QuartzCore.h//添加的预编译#import ASIHTTPRequest.h#import ASIFormDataRequest.h#import ASIHTTPRequestDelegate.h#import ASIHTTPRequestConfig.h#import TBXML.h#import TBXMLHTTP.h#import TBXMLCompression.h#import Config.h#import EGORefreshTableHeaderView.h#import DataSingleton.h#import ImgRecord.h#import IconDownloader.h#import MBProgressHUD.h#import GCDiscreetNotificationView.h#import NdUncaughtExceptionHandler.h#import JSNotifier.h#import AFOSCClient.h#import AFHTTPRequestOperation.h#import AFXMLRequestOperation.h //api定义 #define api_news_list http://www.oschina.net/action/api/news_list#define api_news_detail http://www.oschina.net/action/api/news_detail#define api_post_list http://www.oschina.net/action/api/post_list#define api_post_detail http://www.oschina.net/action/api/post_detail#define api_post_pub http://www.oschina.net/action/api/post_pub#define api_tweet_list http://www.oschina.net/action/api/tweet_list#define api_tweet_detail http://www.oschina.net/action/api/tweet_detail#define api_tweet_delete http://www.oschina.net/action/api/tweet_delete#define api_tweet_pub http://www.oschina.net/action/api/tweet_pub#define api_active_list http://www.oschina.net/action/api/active_list#define api_message_list http://www.oschina.net/action/api/message_list#define api_message_delete http://www.oschina.net/action/api/message_delete#define api_message_pub http://www.oschina.net/action/api/message_pub#define api_comment_list http://www.oschina.net/action/api/comment_list#define api_comment_pub http://www.oschina.net/action/api/comment_pub#define api_comment_reply http://www.oschina.net/action/api/comment_reply#define api_comment_delete http://www.oschina.net/action/api/comment_delete#define api_login_validate https://www.oschina.net/action/api/login_validate#define api_user_info http://www.oschina.net/action/api/user_info#define api_user_information http://www.oschina.net/action/api/user_information#define api_user_updaterelation http://www.oschina.net/action/api/user_updaterelation#define api_notice_clear http://www.oschina.net/action/api/notice_clear#define api_software_detail http://www.oschina.net/action/api/software_detail#define api_blog_detail http://www.oschina.net/action/api/blog_detail#define api_favorite_list http://www.oschina.net/action/api/favorite_list#define api_favorite_add http://www.oschina.net/action/api/favorite_add#define api_favorite_delete http://www.oschina.net/action/api/favorite_delete#define api_user_notice http://www.oschina.net/action/api/user_notice#define api_search_list http://www.oschina.net/action/api/search_list#define api_friends_list http://www.oschina.net/action/api/friends_list#define api_softwarecatalog_list http://www.oschina.net/action/api/softwarecatalog_list#define api_software_list http://www.oschina.net/action/api/software_list#define api_softwaretag_list http://www.oschina.net/action/api/softwaretag_list#define api_blogcomment_list http://www.oschina.net/action/api/blogcomment_list#define api_blogcomment_pub http://www.oschina.net/action/api/blogcomment_pub#define api_my_information http://www.oschina.net/action/api/my_information#define api_blogcomment_delete http://www.oschina.net/action/api/blogcomment_delete#define api_userblog_delete http://www.oschina.net/action/api/userblog_delete#define api_userblog_list http://www.oschina.net/action/api/userblog_list#define api_blog_list http://www.oschina.net/action/api/blog_list#define api_userinfo_update http://www.oschina.net/action/api/portrait_update //宏定义 新闻#define TweetCellIdentifier TweetCellIdentifier#define loadMoreIdentifier loadMoreIdentifier#define NewsCellIdentifier NewsCellIdentifier#define PostCellIdentifier PostCellIdentifier#define MsgCellIdentifier MsgCellIdentifier#define MsgUnitCellIdentifier MsgUnitCellIdentifier#define ActiveCellIdentifier ActiveCellIdentifier#define UserActiveCellIdentifier UserActiveCellIdentifier#define ColorActiveCellIdentifier ColorActiveCellIdentifier#define RTActiveCellIdentifier RTActiveCellIdentifier#define ColorUserActiveCellIdentifier ColorUserActiveCellIdentifier#define ProfielCellIdentifier ProfielCellIdentifier#define CommentCellIdentifier CommentCellIdentifier#define NormalCellIdentifier NormalCellIdentifier#define FavoriteCellIdentifier FavoriteCellIdentifier#define FriendCellIdentifier FriendCellIdentifier#define SoftwareCellIdentifier SoftwareCellIdentifier#define SoftwareCatalogIdentifier SoftwareCatalogIdentifier#define SettingTableIdentifier SettingTableIdentifier#define MyInfoCellIdentifier MyInfoCellIdentifier#define MyPortraitCellIdentifier MyPortraitCellIdentifier #define loadNext20Tip 下面 20 项 . . .#define loadingTip 正在加载 . . .#define networkError 网络无连接#define noNetworkTip 网络无连接 //消息通知固定字符串#define Notification_DetailCommentCount Notification_DetailCommentCount#define Notification_NoticeUpdate Notification_NoticeUpdate#define Notification_TabClick Notification_TabClick //html头部#define HTML_Style style#oschina_title {color: #000000; margin-bottom: 6px; font-weight:bold;}#oschina_title img{vertical-align:middle;margin-right:6px;}#oschina_title a{color:#0D6DA8;}#oschina_outline {color: #707070; font-size: 12px;}#oschina_outline a{color:#0D6DA8;}#oschina_software{color:#808080;font-size:12px}#oschina_body img {max-width: 300px;}#oschina_body {font-size:16px;max-width:300px;line-height:24px;} #oschina_body table{max-width:300px;}#oschina_body pre { font-size:9pt;font-family:Courier New,Arial;border:1px solid #ddd;border-left:5px solid #6CE26C;background:#f6f6f6;padding:5px;}/style#define HTML_Bottom div stylemargin-bottom:60px/ #define USERAGENT OSChina.NET/iOS/5.0 #define AppVersion 1.6.1 #ifdef DEBUG#define debugLog(...) NSLog(__VA_ARGS__)#define debugMethod() NSLog(%s, __func__)#else#define debugLog(...)#define debugMethod()#endif #endif 复制代码 我们看到有这样些文件也被添加到里面可能会想难道这些头文件变化不大吗 //添加的预编译#import ASIHTTPRequest.h#import ASIFormDataRequest.h#import ASIHTTPRequestDelegate.h#import ASIHTTPRequestConfig.h#import TBXML.h#import TBXMLHTTP.h#import TBXMLCompression.h#import Config.h#import EGORefreshTableHeaderView.h#import DataSingleton.h#import ImgRecord.h#import IconDownloader.h#import MBProgressHUD.h#import GCDiscreetNotificationView.h#import NdUncaughtExceptionHandler.h#import JSNotifier.h#import AFOSCClient.h#import AFHTTPRequestOperation.h#import AFXMLRequestOperation.h 复制代码 其实这些文件特殊之处在于他们都是第三方类库的头文件第三方类库将一些对象进行高度封装留下接口然后我们根据类库接口直接调用就可以这些第三方类库一般都比iOS原生自带的更加简单易用比如TBXML解析库比iOS自带的NSXMLPaser解析器速度功能上都会好一些还有一些宏定义都是比较常用方式的宏定义比如定义的开源中国社区的api接口这些接口变得当然很少了然后就剩下最后面的 #ifdef DEBUG#define debugLog(...) NSLog(__VA_ARGS__)#define debugMethod() NSLog(%s, __func__)#else#define debugLog(...)#define debugMethod()#endif 复制代码 工程有Debug Version和Release VersionDebug Version是程序开发过程中版本它包含了所有调试信息一些常用的NSLog打印日志在程序调试过程工根据我们设置的调试信息可以看出什么地方出错我们在运行运行一个小程序的时候会不会首先就想到进行断点调试呢应该是首先想着NSLog一下看看哪个函数方法没执行看看是不是哪个数组的值没取出来。Release Version是发布版本不打印NSLog可以加快程序运行速度减少内存使用。 但是到一个大工程中会有很多很多这样的NSLog,在我们工程完美运行的时候发布Release 版本的时候难道我们去一行行的注释调NSLog吗假如工程现在原来基础上发布一个version 1.2版本的我们在修改程序的时候岂不是还把原来注释给取消那就很麻烦很麻烦了。所以此处用到了宏指令上段代码的意思就是 用宏指令做一个判断如果DEBUG为真则编译#ifdef到#endif宏定义否则编译器就不编译这个DEBUG在哪设置呢在 Target Build Settings Preprocessor Macros Debug 里有一个DEBUG1。现在我们来做一个测试取一个宏指令放到OSAppDelegate.m的application:didFinishLaunchingWithOptions:方法中,并用同一个NSLog做一个对比NSLog(%s, __func__);debugMethod();首先设置为Debug模式下Product--Edit Scheme跳转到这个界面当我设置Build Configuration成Debug时打印效果图当我设置Build Configuration成Release的打印时效果图当Run Test Profile Analyze Archive的时候都可以根据需要设置Debug和Release两个模式运行所以我们完全可以用一个宏指令来设置是否打印调试信息转载于:https://www.cnblogs.com/xubojoy/p/3934653.html
