Swift-使用drawInRect:withAttributes绘制文本:
我对Xcode 6.1 GM有一个奇怪的问题。
let text: NSString = "A"let font = NSFont(name: "Helvetica Bold", size: 14.0)
let textRect: NSRect = NSMakeRect(5, 3, 125, 18)
let textStyle = NSMutableParagraphStyle.defaultParagraphStyle().mutableCopy() as NSMutableParagraphStyle
textStyle.alignment = NSTextAlignment.LeftTextAlignment
let textColor = NSColor(calibratedRed: 0.147, green: 0.222, blue: 0.162, alpha: 1.0)
let textFontAttributes = [
NSFontAttributeName: font,
NSForegroundColorAttributeName: textColor,
NSParagraphStyleAttributeName: textStyle
]
text.drawInRect(NSOffsetRect(textRect, 0, 1), withAttributes: textFontAttributes)
错误处在让texFontAttributes …
Cannot convert the expression's type 'Dictionary' to type 'DictionaryLiteralConvertible'
直到Xcode 6.1 GM,此代码才能正常工作。
当我尝试将textFontAttributes声明为NSDictionary时,错误消息更改为:
Cannot convert the expression's type 'NSDictionary' to type 'NSString!'
我不知道如何解决这个问题:(
回答:
问题在于这font
是可选的,因为便利构造函数现在返回可选值,因此font
需要将其解包为字典中的值:
if let actualFont = font { let textFontAttributes = [
NSFontAttributeName: actualFont,
NSForegroundColorAttributeName: textColor,
NSParagraphStyleAttributeName: textStyle
]
text.drawInRect(NSOffsetRect(textRect, 0, 1), withAttributes: textFontAttributes)
}
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