将其放在按钮的action方法中，或者你想使用浏览器来tweet你的文本的方法中Swift 3.0：

let tweetText = "your text"
let tweetUrl = "http://stackoverflow.com/"

let shareString = "https://twitter.com/intent/tweet?text=\(tweetText)&url=\(tweetUrl)"

// encode a space to %20 for example
let escapedShareString = shareString.addingPercentEncoding(withAllowedCharacters: CharacterSet.urlQueryAllowed)!

// cast to an url
let url = URL(string: escapedShareString)

// open in safari
UIApplication.shared.openURL(url!)

结果：

@ronatory的解决方案很有魅力。它还打开一个Twitter应用程序，如果它已经安装在用户的设备上。
对于swift 5+，使用UIApplication.shared.open(url!)而不是UIApplication.shared.openURL(url!)，因为它已被弃用。

看看Fabric.io。此SDK允许您直接从应用程序撰写推文。

let composer = TWTRComposer()

composer.setText("just setting up my Fabric")
composer.setImage(UIImage(named: "fabric"))

// Called from a UIViewController
composer.showFromViewController(self) { result in
    if (result == TWTRComposerResult.Cancelled) {
         print("Tweet composition cancelled")
    }
    else {
       print("Sending tweet!")
    }
}

let tweetText = "hy" 
let tweetUrl = "http://rimmi/" 

let shareString = "https://twitter.com/intent/tweet?text=\(tweetText)&url=\(tweetUrl)"

// encode a space to %20 for example 
let escapedShareString = shareString.addingPercentEncoding(withAllowedCharacters: CharacterSet.urlQueryAllowed)!

// cast to an url 
let url = URL(string: escapedShareString)

// open in safari 
UIApplication.shared.openURL(url!)

在SwiftUI Swift5中使用

Button {
    let tweetText = "Text for share"
    let shareString = "https://twitter.com/intent/tweet?text=\(tweetText)"
    let escapedShareString = shareString.addingPercentEncoding(withAllowedCharacters: CharacterSet.urlQueryAllowed)!
    let url = URL(string: escapedShareString)
    UIApplication.shared.open(url!)
} label: {
    Text("Share on Twitter")
}