使用NSMutableAttributedStrings快速更改文本颜色

Question

I have a UITableView and i would like to display the text of each row using different colors within the same line.

I've tried this code, trying to translate from Obj-C but i cannot have it working

        let object = self.fetchedResultsController.objectAtIndexPath(indexPath) as NSManagedObject

        var attrString: NSMutableAttributedString = NSMutableAttributedString(string: object.valueForKey("example1")!.description)
        attrString.addAttribute(NSForegroundColorAttributeName, value: UIColor.redColor(), range: NSMakeRange(0, attrString.length))

        var stringToCell:String = String(format: "%@    %@", attrString, object.valueForKey("example2")!.description)
        cell.textLabel?.text = stringToCell

The output of all this is

where the number 34 correspond to object.valueForKey("example1")!.description , so the problem is that the number is not red, and the second part ( object.valueForKey("example2")!.description ) is replaced by { .

If I leave this piece of code regarding NSAttributedString the row text is displayed correctly.

Answer 1

I think the problem might lie in assigning to cell.textLabel?.text instead of cell.textLabel?.attributedText . Perhaps something like this:

let object = self.fetchedResultsController.objectAtIndexPath(indexPath) as NSManagedObject

var attrString: NSMutableAttributedString = NSMutableAttributedString(string: object.valueForKey("example1")!.description)
attrString.addAttribute(NSForegroundColorAttributeName, value: UIColor.redColor(), range: NSMakeRange(0, attrString.length))

var descString: NSMutableAttributedString = NSMutableAttributedString(string:  String(format: "    %@", object.valueForKey("example2")!.description))
descString.addAttribute(NSForegroundColorAttributeName, value: UIColor.blackColor(), range: NSMakeRange(0, descString.length))

attrString.appendAttributedString(descString);
cell.textLabel?.attributedText = attrString

Wasn't sure if you wanted the second part of the string to be red or another color so I made it black.

Answer 2

If you can, avoid using NSMutableAttributedString and just pass in the attributes with the constructor:

private func PullToRefreshAttributedStringWithColor(color:UIColor) -> NSAttributedString {
  return NSAttributedString(string: "Pull to Refresh", attributes: [
      NSForegroundColorAttributeName:color
    ])
}

Answer 3

Here is a example of attribute text Swift 3

let mainText = "Here is a example of attributedString"
let attributeText = "attributedString"
let range = (mainText as NSString).range(of: attributeText)
let attributedString = NSMutableAttributedString(string:mainText)

attributedString.addAttribute(NSAttributedStringKey.foregroundColor, value: UIColor.red, range: range)
attribute.addAttribute(NSFontAttributeName, value: UIFont.systemFont(ofSize: 14) , range: range)

lblTitle.attributedText = attributedString