初创公司技术负责人规划_初创公司将在2020年采用技术堆栈
作者：互联网
创公司技术负责人规划
JavaScript, CSS, and HTML are some of the main technologies that help you to build robust app solutions. So, if you are looking to build smart web applications for your business, then I advise you to jump to my idea of cross-platform and open-source development frameworks right away.
JavaScript，CSS和HTML是帮助您构建可靠的应用程序解决方案的一些主要技术。 因此，如果您希望为您的业务构建智能Web应用程序，那么我建议您立即跳出我对跨平台和开源开发框架的想法。
Here is the list of the tech stacks for app developers to use in 2020.
以下是2020年供应用程序开发人员使用的技术堆栈列表。
1.使用React Native创建适合移动设备的应用程序 (1. Create Mobile-Friendly Apps With React Native )
React Native is a popular cross-platform framework that has been launched by Facebook in 2013. And, it is always in the favored list of our team of app developers. It can be useful for your business too because React Native allows your app to follow a model coded in a language native for each platform. And, thanks to its library, you do not need to create separate apps for iOS, Android, and the web.
React Native是Facebook于2013年推出的一种流行的跨平台框架。而且，它始终在我们的应用程序开发人员团队的青睐中。 这对您的业务也很有用，因为React Native允许您的应用遵循为每个平台使用本机语言编码的模型。 而且，由于其库，您无需为iOS，Android和Web创建单独的应用程序。
Another good thing about the React Native Development is it has sets of pre-written codes that help developers in adding specific functionalities to your app with fewer bugs on the way, and for less money.
React Native Development的另一个好处是，它具有预先编写的代码集，可帮助开发人员在途中减少错误并以更少的钱为应用程序添加特定功能。
几个例子 (Few Examples)
:
：
Myntra(在线购物行业) (Myntra (Online Shopping Industry))
Myntra shopping portal makes it easier for you to shop on mobile. The best part is their presentation of catalogs, profiles, and order management. Using React Native, Myntra is offering an amazing UI and UX to their users.
Myntra购物门户网站使您可以更轻松地在移动设备上购物。 最好的部分是他们对目录，配置文件和订单管理的介绍。 使用React Native，Myntra为用户提供了惊人的UI和UX。
Instagram(通讯) (Instagram (Messaging))
With React Native it’s really easy for the Instagram app to make it maintenance on both iOS and Android.
借助React Native，Instagram应用程序很容易在iOS和Android上进行维护。
彭博(金融业) (Bloomberg (Finance Industry))
By adding React Native to their app development, Bloomberg achieved simultaneous updation of the app for cross-platforms.
通过将React Native添加到他们的应用程序开发中，彭博社实现了跨平台应用程序的同时更新。
2. Flutter用于构建智能业务应用程序 (2. Flutter for Building Smart Business Apps)
Flutter was launched by Google and is one of the best platforms for open-source and cross-platform mobile application development. It well suits the development of hybrid apps and enables smooth and easy development of iOS and Android apps. It is based on Dart, which is an object-oriented programming language. Flutter makes the use of the Skia which is a 2D rendering engine to develop the visuals. These visuals make your app look good and feel great with advanced UI elements.
Flutter由Google发布，是开源和跨平台移动应用程序开发的最佳平台之一。 它非常适合混合应用程序的开发，并可以轻松便捷地开发iOS和Android应用程序。 它基于Dart(一种面向对象的编程语言)。 Flutter利用Skia(一种2D渲染引擎)来开发视觉效果。 这些视觉效果使您的应用看起来不错，并通过高级UI元素感觉很棒。
When coding with flutter you can use it in a variety of IDEs (Integrated Development Environments). You can also use different themes for Android and iOS.
使用flutter进行编码时，可以在各种IDE(集成开发环境)中使用它。 您还可以为Android和iOS使用不同的主题。
以下是Flutter制作的一些流行应用： (Here are some popular apps made with Flutter: )
阿里巴巴(电子商务) (Alibaba (E-commerce))
The Alibaba eCommerce app is a place for global trade and is totally based on the Flutter that allows its users to buy products from suppliers around the world.
阿里巴巴电子商务应用程序是全球贸易的场所，完全基于Flutter，它允许用户从世界各地的供应商处购买产品。
Watermaniac(健康和健身) (Watermaniac (Health and Fitness) )
Watermaniac is a health and fitness app that enables its users to track the amount of water they drink and send customized notifications to remind users about drinking water.
Watermaniac是一款健康和健身应用程序，它使用户能够跟踪他们所喝的水量并发送自定义通知以提醒用户有关饮用水的信息。
密码术(财务) (Cryptograph (Finance))
CryptoGraph app provides data of around 1600 cryptocurrencies such as Bitcoin, Ethereum, etc. The app is based on Flutter and also allows users to select and add coins to favorites for easy tracking, and more features are there.
3. Xamarin MFactor (3. Xamarin MFactor)
When talking about Xamarin apps, you must go with the trends. Like this year, Xamarin launched the MFactor which is a Visual Studio for Mac extension that can be used for the development of useful business apps for Android, iOS, and Windows. MFactor suggests static, grid rows, columns, image assets, and much more. In other words, it helps Xamarin developers to save a lot of their time and efforts.
在谈论Xamarin应用程序时，您必须顺应潮流。 与今年一样，Xamarin推出了MFactor，这是Visual Studio for Mac扩展，可用于开发适用于Android，iOS和Windows的有用业务应用程序。 MFactor建议使用静态，网格行，列，图像资产等等。 换句话说，它可以帮助Xamarin开发人员节省大量时间和精力。
Xamarin popularity has been taking the world by storm and it has grown to over 1.6 million developers across 120 countries. Xamarin app development is the choice of over 15,000 companies in the fields of healthcare, transport, power & energy, transport, media, and many more.
Xamarin的受欢迎程度已席卷全球，在120个国家/地区拥有超过160万开发人员。 Xamarin应用程序开发是医疗，运输，电力与能源，运输，媒体等领域超过15,000家公司的选择。
几个例子： (Few examples: )
阿拉斯加航空(旅游业) (Alaska Airlines (Travel Industry))
Alaska Airlines’ uses Xamarin mobile app and gives their users the options to explore and book trips in a hassle-free way through airports.
阿拉斯加航空(Alaska Airlines)使用Xamarin移动应用程序，并为用户提供了无忧地探索和预订穿越机场旅行的选项。
OLO Food App(食品工业) (OLO Food App (Food Industry))
OLO is an online ordering food application by Xamarin. It helps OLO users to find restaurants and different cuisines. Users also are given the ability to track their food orders live on the app.
OLO是Xamarin的在线订购食品应用程序。 它可以帮助OLO用户找到餐馆和其他美食。 用户还可以实时在应用程序上跟踪他们的食物订单。
世界银行(银行业) (The World Bank (Banking Industry))
The World Bank has built its own app called the Survey Solutions which is based on Xamarin. It is a tool for conducting surveys that manage, collects, sort, and aggregates data for the World Bank. The app helps in getting a fair insight into market updates and customer reviews for banking products and other updates.
世界银行基于Xamarin构建了自己的名为Survey Solutions的应用程序。 它是进行调查的工具，可以管理，收集，分类和汇总世界银行的数据。 该应用程序有助于获得对市场更新以及银行产品和其他更新的客户评论的公正见解。
4.离子V.4 (4. Ionic V.4)
Ionics new version (v.4) supports functions like animations, UI library distribution, supporting Angular tooling, bug fixes, special pages, order flow, and even more. According to market reports, Ionic is the best framework used for the development of mobile apps and approximately 25,993 applications use Ionic as of 2019-20. And, the best part is — it is free of cost.
Ionic的新版本(v.4)支持动画，UI库分发，支持Angular工具，错误修复，特殊页面，订单流程等功能。 根据市场报告，Ionic是用于开发移动应用程序的最佳框架，截至2019-20年，约有25,993个应用程序使用Ionic。 而且，最好的部分是-它是免费的。
No doubt, Ionic is regarded as one of the best frameworks for the development of business apps. What’s more interesting to note is that it can work well with platforms like Angular, PhoneGap, and Cordova.
毫无疑问，Ionic被视为开发业务应用程序的最佳框架之一。 值得一提的是，它可以与Angular，PhoneGap和Cordova等平台配合使用。
使用Ionic构建的应用程序的一些示例： (Some examples of apps built with Ionic: )
麦当劳Turkiye(酒店业) (McDonald’s Turkiye (Hotel Industry))
We all know that McDonald’s pays a lot of attention, time, and effort to maintain their consumer base. McDonald Turkiye is a food ordering app based on the Ionic platform and gives you awesome deals and promotional offers. In turn, McDonald receives huge applause from customers.
众所周知，麦当劳在保持消费者基础方面投入了大量精力，时间和精力。 McDonald Turkiye是一款基于Ionic平台的食品订购应用程序，可为您提供超值优惠和促销优惠。 反过来，麦当劳得到了客户的热烈掌声。
MarketWatch(金融业) (MarketWatch (Finance Industry))
This is a free news and market data app for Android and iOS users. Using MarketWatch you can have round the clock access to industry news, stock market quotes, and much more.
这是面向Android和iOS用户的免费新闻和市场数据应用程序。 使用MarketWatch，您可以全天候访问行业新闻，股市行情等等。
Sworkit(健康行业) (Sworkit (Health Industry))
Sworkit app is based on Ionic and is compatible with all of your iOS and Android devices. It offers you a range of exercises also you can set the length of your workout with the type of exercises you requested.
Sworkit应用程序基于Ionic并与您的所有iOS和Android设备兼容。 它为您提供了一系列锻炼，您还可以根据要求的锻炼类型设置锻炼的时间。
5.框架7 (5. Framework 7)
Framework7 is another best choice for free and open-source mobile application development. It is powered by Apache Cordova with native interface elements. This tool allows the recreation of standard iOS designs and Google’s Material Design patterns to change the “native look” that mobile users expect.
Framework7是免费和开源移动应用程序开发的另一个最佳选择。 它由具有本地接口元素的Apache Cordova提供支持。 该工具允许重新创建标准的iOS设计和Google的Material Design模式，以改变移动用户期望的“本机外观”。
Framework7 helps developers make copies of iOS designs and allows you to build apps on any platform — PWA, Cordova, and ELECTRON. Framework7 comes with the ready to use elements and widgets like popup, dialogs, form elements, list views, side panels, and more.
Framework7可帮助开发人员制作iOS设计的副本，并允许您在任何平台(PWA，Cordova和ELECTRON)上构建应用程序。 Framework7附带了随时可用的元素和小部件，如弹出窗口，对话框，表单元素，列表视图，侧面板等。
几个例子： (Few examples:)
收集(文件) (Collect (Documents))
With the app like Collect, you need not worry about storing your documents being spread over multiple apps. The Collect is based on Framework7 and capable of handling information and documents with its features like built-in rich text editing and more.
使用“收集”之类的应用程序，您无需担心存储文档分散在多个应用程序中的情况。 收集器基于Framework7，并具有内置富文本编辑等功能，能够处理信息和文档。
Ad-Lister is an app that helps manage around 2,823 eBay stores. The app allows small to large scale eBay business sellers to focus on driving more sales and saving their time.
Ad-Lister是一款可帮助管理约2,823个eBay商店的应用程序。 该应用程序允许小型到大型eBay商业卖家专注于推动更多销售并节省时间。
YouBeep(移动购物) (YouBeep (Mobile Shopping) )
YouBeep is an app for mobile shopping that helps reduce your checkout time and improve the overall customer shopping experience. It is best to use for online retailers looking to improve their customer satisfaction.
YouBeep是一款用于移动购物的应用程序，可帮助您减少结帐时间并改善整体客户购物体验。 最好用于希望提高客户满意度的在线零售商。
结语！ (Wrapping it Up!)
Now, you’ve reached the end of the cross-platform and open-source mobile application development tools. As of this moment, you’re still wondering whether which one is the right tool for your business, then I suggest you take this list for your reference.
现在，您已经到了跨平台和开源移动应用程序开发工具的结尾。 到目前为止，您仍然想知道哪种工具适合您的业务，然后建议您将此列表作为参考。
Again thanks for reading! If you have ever tried any of the technology stacks, please share your views in the comments section. Or, if you’re excited to try a new one out, then let me know.
再次感谢您的阅读！ 如果您曾经尝试过任何一种技术堆栈，请在评论部分中分享您的观点。 或者，如果您很高兴尝试新的产品，请告诉我。
Or, if you are looking to hire web developers from a reputed and reliable development company, you can easily get your queries to .
或者，如果您想聘请知名的可靠开发公司的Web开发人员，则可以轻松地向查询。
翻译自:
初创公司技术负责人规划
初创公司技术负责人规划 JavaScript, CSS, and HTML are some of the main technologies that help you to build robust app solutions. So, if you are looking to build smart web applications for your business, then I advise you to jump to my idea of cross-platform and open-source development frameworks right away. JavaScript，CSS和HTML是帮助您构建可靠的应用程序解决方案的一些主要技术。 因此，如果您希望为您的业务构建智能Web应用程序，那么我建议您立即跳出我对跨平台和开源开发框架的想法。 Here is the list of the tech stacks for app developers to use in 2020. 以下是2020年供应用程序开发人员使用的技术堆栈列表。 1.使用React Native创建适合移动设备的应用程序 (1. Create Mobile-Friendly Apps With React Native ) React Native is a popular cross-platform framework that has been launched by Facebook in 2013. And, it is always in the favored list of our team of app developers. It can be useful for your business too because React Native allows your app to follow a model coded in a language native for each platform. And, thanks to its library, you do not need to create separate apps for iOS, Android, and the web. React Native是Facebook于2013年推出的一种流行的跨平台框架。而且，它始终在我们的应用程序开发人员团队的青睐中。 这对您的业务也很有用，因为React Native允许您的应用遵循为每个平台使用本机语言编码的模型。 而且，由于其库，您无需为iOS，Android和Web创建单独的应用程序。 Another good thing about the React Native Development is it has sets of pre-written codes that help developers in adding specific functionalities to your app with fewer bugs on the way, and for less money. React Native Development的另一个好处是，它具有预先编写的代码集，可帮助开发人员在途中减少错误并以更少的钱为应用程序添加特定功能。 几个例子 (Few Examples) : ： Myntra(在线购物行业) (Myntra (Online Shopping Industry)) Myntra shopping portal makes it easier for you to shop on mobile. The best part is their presentation of catalogs, profiles, and order management. Using React Native, Myntra is offering an amazing UI and UX to their users. Myntra购物门户网站使您可以更轻松地在移动设备上购物。 最好的部分是他们对目录，配置文件和订单管理的介绍。 使用React Native，Myntra为用户提供了惊人的UI和UX。 Instagram(通讯) (Instagram (Messaging)) With React Native it’s really easy for the Instagram app to make it maintenance on both iOS and Android. 借助React Native，Instagram应用程序很容易在iOS和Android上进行维护。 彭博(金融业) (Bloomberg (Finance Industry)) By adding React Native to their app development, Bloomberg achieved simultaneous updation of the app for cross-platforms. 通过将React Native添加到他们的应用程序开发中，彭博社实现了跨平台应用程序的同时更新。 2. Flutter用于构建智能业务应用程序 (2. Flutter for Building Smart Business Apps) Flutter was launched by Google and is one of the best platforms for open-source and cross-platform mobile application development. It well suits the development of hybrid apps and enables smooth and easy development of iOS and Android apps. It is based on Dart, which is an object-oriented programming language. Flutter makes the use of the Skia which is a 2D rendering engine to develop the visuals. These visuals make your app look good and feel great with advanced UI elements. Flutter由Google发布，是开源和跨平台移动应用程序开发的最佳平台之一。 它非常适合混合应用程序的开发，并可以轻松便捷地开发iOS和Android应用程序。 它基于Dart(一种面向对象的编程语言)。 Flutter利用Skia(一种2D渲染引擎)来开发视觉效果。 这些视觉效果使您的应用看起来不错，并通过高级UI元素感觉很棒。 When coding with flutter you can use it in a variety of IDEs (Integrated Development Environments). You can also use different themes for Android and iOS. 使用flutter进行编码时，可以在各种IDE(集成开发环境)中使用它。 您还可以为Android和iOS使用不同的主题。 以下是Flutter制作的一些流行应用： (Here are some popular apps made with Flutter: ) 阿里巴巴(电子商务) (Alibaba (E-commerce)) The Alibaba eCommerce app is a place for global trade and is totally based on the Flutter that allows its users to buy products from suppliers around the world. 阿里巴巴电子商务应用程序是全球贸易的场所，完全基于Flutter，它允许用户从世界各地的供应商处购买产品。 Watermaniac(健康和健身) (Watermaniac (Health and Fitness) ) Watermaniac is a health and fitness app that enables its users to track the amount of water they drink and send customized notifications to remind users about drinking water. Watermaniac是一款健康和健身应用程序，它使用户能够跟踪他们所喝的水量并发送自定义通知以提醒用户有关饮用水的信息。 密码术(财务) (Cryptograph (Finance)) CryptoGraph app provides data of around 1600 cryptocurrencies such as Bitcoin, Ethereum, etc. The app is based on Flutter and also allows users to select and add coins to favorites for easy tracking, and more features are there. 3. Xamarin MFactor (3. Xamarin MFactor) When talking about Xamarin apps, you must go with the trends. Like this year, Xamarin launched the MFactor which is a Visual Studio for Mac extension that can be used for the development of useful business apps for Android, iOS, and Windows. MFactor suggests static, grid rows, columns, image assets, and much more. In other words, it helps Xamarin developers to save a lot of their time and efforts. 在谈论Xamarin应用程序时，您必须顺应潮流。 与今年一样，Xamarin推出了MFactor，这是Visual Studio for Mac扩展，可用于开发适用于Android，iOS和Windows的有用业务应用程序。 MFactor建议使用静态，网格行，列，图像资产等等。 换句话说，它可以帮助Xamarin开发人员节省大量时间和精力。 Xamarin popularity has been taking the world by storm and it has grown to over 1.6 million developers across 120 countries. Xamarin app development is the choice of over 15,000 companies in the fields of healthcare, transport, power & energy, transport, media, and many more. Xamarin的受欢迎程度已席卷全球，在120个国家/地区拥有超过160万开发人员。 Xamarin应用程序开发是医疗，运输，电力与能源，运输，媒体等领域超过15,000家公司的选择。 几个例子： (Few examples: ) 阿拉斯加航空(旅游业) (Alaska Airlines (Travel Industry)) Alaska Airlines’ uses Xamarin mobile app and gives their users the options to explore and book trips in a hassle-free way through airports. 阿拉斯加航空(Alaska Airlines)使用Xamarin移动应用程序，并为用户提供了无忧地探索和预订穿越机场旅行的选项。 OLO Food App(食品工业) (OLO Food App (Food Industry)) OLO is an online ordering food application by Xamarin. It helps OLO users to find restaurants and different cuisines. Users also are given the ability to track their food orders live on the app. OLO是Xamarin的在线订购食品应用程序。 它可以帮助OLO用户找到餐馆和其他美食。 用户还可以实时在应用程序上跟踪他们的食物订单。 世界银行(银行业) (The World Bank (Banking Industry)) The World Bank has built its own app called the Survey Solutions which is based on Xamarin. It is a tool for conducting surveys that manage, collects, sort, and aggregates data for the World Bank. The app helps in getting a fair insight into market updates and customer reviews for banking products and other updates. 世界银行基于Xamarin构建了自己的名为Survey Solutions的应用程序。 它是进行调查的工具，可以管理，收集，分类和汇总世界银行的数据。 该应用程序有助于获得对市场更新以及银行产品和其他更新的客户评论的公正见解。 4.离子V.4 (4. Ionic V.4) Ionics new version (v.4) supports functions like animations, UI library distribution, supporting Angular tooling, bug fixes, special pages, order flow, and even more. According to market reports, Ionic is the best framework used for the development of mobile apps and approximately 25,993 applications use Ionic as of 2019-20. And, the best part is — it is free of cost. Ionic的新版本(v.4)支持动画，UI库分发，支持Angular工具，错误修复，特殊页面，订单流程等功能。 根据市场报告，Ionic是用于开发移动应用程序的最佳框架，截至2019-20年，约有25,993个应用程序使用Ionic。 而且，最好的部分是-它是免费的。 No doubt, Ionic is regarded as one of the best frameworks for the development of business apps. What’s more interesting to note is that it can work well with platforms like Angular, PhoneGap, and Cordova. 毫无疑问，Ionic被视为开发业务应用程序的最佳框架之一。 值得一提的是，它可以与Angular，PhoneGap和Cordova等平台配合使用。 使用Ionic构建的应用程序的一些示例： (Some examples of apps built with Ionic: ) 麦当劳Turkiye(酒店业) (McDonald’s Turkiye (Hotel Industry)) We all know that McDonald’s pays a lot of attention, time, and effort to maintain their consumer base. McDonald Turkiye is a food ordering app based on the Ionic platform and gives you awesome deals and promotional offers. In turn, McDonald receives huge applause from customers. 众所周知，麦当劳在保持消费者基础方面投入了大量精力，时间和精力。 McDonald Turkiye是一款基于Ionic平台的食品订购应用程序，可为您提供超值优惠和促销优惠。 反过来，麦当劳得到了客户的热烈掌声。 MarketWatch(金融业) (MarketWatch (Finance Industry)) This is a free news and market data app for Android and iOS users. Using MarketWatch you can have round the clock access to industry news, stock market quotes, and much more. 这是面向Android和iOS用户的免费新闻和市场数据应用程序。 使用MarketWatch，您可以全天候访问行业新闻，股市行情等等。 Sworkit(健康行业) (Sworkit (Health Industry)) Sworkit app is based on Ionic and is compatible with all of your iOS and Android devices. It offers you a range of exercises also you can set the length of your workout with the type of exercises you requested. Sworkit应用程序基于Ionic并与您的所有iOS和Android设备兼容。 它为您提供了一系列锻炼，您还可以根据要求的锻炼类型设置锻炼的时间。 5.框架7 (5. Framework 7) Framework7 is another best choice for free and open-source mobile application development. It is powered by Apache Cordova with native interface elements. This tool allows the recreation of standard iOS designs and Google’s Material Design patterns to change the “native look” that mobile users expect. Framework7是免费和开源移动应用程序开发的另一个最佳选择。 它由具有本地接口元素的Apache Cordova提供支持。 该工具允许重新创建标准的iOS设计和Google的Material Design模式，以改变移动用户期望的“本机外观”。 Framework7 helps developers make copies of iOS designs and allows you to build apps on any platform — PWA, Cordova, and ELECTRON. Framework7 comes with the ready to use elements and widgets like popup, dialogs, form elements, list views, side panels, and more. Framework7可帮助开发人员制作iOS设计的副本，并允许您在任何平台(PWA，Cordova和ELECTRON)上构建应用程序。 Framework7附带了随时可用的元素和小部件，如弹出窗口，对话框，表单元素，列表视图，侧面板等。 几个例子： (Few examples:) 收集(文件) (Collect (Documents)) With the app like Collect, you need not worry about storing your documents being spread over multiple apps. The Collect is based on Framework7 and capable of handling information and documents with its features like built-in rich text editing and more. 使用“收集”之类的应用程序，您无需担心存储文档分散在多个应用程序中的情况。 收集器基于Framework7，并具有内置富文本编辑等功能，能够处理信息和文档。 Ad-Lister is an app that helps manage around 2,823 eBay stores. The app allows small to large scale eBay business sellers to focus on driving more sales and saving their time. Ad-Lister是一款可帮助管理约2,823个eBay商店的应用程序。 该应用程序允许小型到大型eBay商业卖家专注于推动更多销售并节省时间。 YouBeep(移动购物) (YouBeep (Mobile Shopping) ) YouBeep is an app for mobile shopping that helps reduce your checkout time and improve the overall customer shopping experience. It is best to use for online retailers looking to improve their customer satisfaction. YouBeep是一款用于移动购物的应用程序，可帮助您减少结帐时间并改善整体客户购物体验。 最好用于希望提高客户满意度的在线零售商。 结语！ (Wrapping it Up!) Now, you’ve reached the end of the cross-platform and open-source mobile application development tools. As of this moment, you’re still wondering whether which one is the right tool for your business, then I suggest you take this list for your reference. 现在，您已经到了跨平台和开源移动应用程序开发工具的结尾。 到目前为止，您仍然想知道哪种工具适合您的业务，然后建议您将此列表作为参考。 Again thanks for reading! If you have ever tried any of the technology stacks, please share your views in the comments section. Or, if you’re excited to try a new one out, then let me know. 再次感谢您的阅读！ 如果您曾经尝试过任何一种技术堆栈，请在评论部分中分享您的观点。 或者，如果您很高兴尝试新的产品，请告诉我。 Or, if you are looking to hire web developers from a reputed and reliable development company, you can easily get your queries to . 或者，如果您想聘请知名的可靠开发公司的Web开发人员，则可以轻松地向查询。 翻译自: 初创公司技术负责人规划