Swift

textView.text = "Hello, world!"

Objective-C:

textView.text = @"Hello, world!";

// Modify some of the attributes of the attributed string.
let attributedText = NSMutableAttributedString(attributedString: textView.attributedText!)

// Use NSString so the result of rangeOfString is an NSRange.
let text = textView.text! as NSString

// Find the range of each element to modify.
let tintedRange = text.range(of: NSLocalizedString("tinted", comment: ""))
let highlightedRange = text.range(of: NSLocalizedString("highlighted", comment: ""))

// Add tint.
attributedText.addAttribute(NSForegroundColorAttributeName, value: UIColor.blue, range: tintedRange)

// Add highlight.
attributedText.addAttribute(NSBackgroundColorAttributeName, value: UIColor.yellow, range: highlightedRange)

textView.attributedText = attributedText

Swift

textView.textAlignment = .left

Objective-C

textView.textAlignment = NSTextAlignmentLeft;

Responding to Editing Notifications

• textViewShouldBeginEditing(_:)
• textViewDidBeginEditing(_:)
• textViewShouldEndEditing(_:)
• textViewDidEndEditing(_:)

Responding to Text Changes

• textView(_:shouldChangeTextIn:replacementText:)
• textViewDidChange(_:)

Responding to URL

• textView(_: UITextView, shouldInteractWithURL: NSURL, inRange: NSRange) -> Bool

Swift

//System Font
textView.font = UIFont.systemFont(ofSize: 12)

//Font of your choosing
textView.font = UIFont(name: "Font Name", size: 12)

Objective-C

//System Font
textView.font = [UIFont systemFontOfSize:12];

//Font of your choosing
textView.font = [UIFont fontWithName:@"Font Name" size:12];

Swift

textView.textColor = UIColor.red

Objective-C

textView.textColor = [UIColor redColor];

NSString *htmlString = @"<p> This is an <b>HTML</b> text</p>";
NSAttributedString *attributedString = [[NSMutableAttributedString alloc]
                                                        initWithData: [htmlString dataUsingEncoding:NSUnicodeStringEncoding]
                                                        options: @{ NSDocumentTypeDocumentAttribute: NSHTMLTextDocumentType }
                                                        documentAttributes: nil
                                                        error: nil
                                                        ];
                _yourTextView.attributedText = attributedString;
                // If you want to modify the font
                field.font = [UIFont fontWithName:@"Raleway-Regular" size:15];

UITextView has built in support to auto detect a variety of data. The data that is able to be auto-detected currently includes:

enum {
   UIDataDetectorTypePhoneNumber   = 1 << 0,
   UIDataDetectorTypeLink          = 1 << 1,
   UIDataDetectorTypeAddress       = 1 << 2,
   UIDataDetectorTypeCalendarEvent = 1 << 3,
   UIDataDetectorTypeNone          = 0,
   UIDataDetectorTypeAll           = NSUIntegerMax
};

Enabling auto-detection

// you may add as many as you like by using the `|` operator between options
textView.dataDetectorTypes = (UIDataDetectorTypeLink | UIDataDetectorTypePhoneNumber);

If enabled, the text will appear as a hyperlink on the UITextView

Clickable data

To allow the link to be clicked (which will result in different actions depending on the data type) you must ensure that the UITextView is selectable but not editable and that user interaction is enabled

textView.editable = NO;
textView.selectable = YES;
textView.userInteractionEnabled = YES; // YES by default

Swift

if let text = self.textView.text where !text.isEmpty {
    // Do stuff for text
} else {
    // Do stuff for nil text or empty string
}

Objective-C

if (self.textView.text.length > 0){
    // Do stuff for text
}   else {
    // Do stuff for nil text or empty string
}

Useful information

The very beginning of the text field text:

let startPosition: UITextPosition = textView.beginningOfDocument

The very end of the text field text:

let endPosition: UITextPosition = textView.endOfDocument

The currently selected range:

let selectedRange: UITextRange? = textView.selectedTextRange

Get cursor position

if let selectedRange = textView.selectedTextRange {
    
    let cursorPosition = textView.offsetFromPosition(textView.beginningOfDocument, toPosition: selectedRange.start)
    
    print("\(cursorPosition)")
}

Set cursor position

In order to set the position, all of these methods are actually setting a range with the same start and end values.

To the beginning

let newPosition = textView.beginningOfDocument
textView.selectedTextRange = textView.textRangeFromPosition(newPosition, toPosition: newPosition)

To the end

let newPosition = textView.endOfDocument
textView.selectedTextRange = textView.textRangeFromPosition(newPosition, toPosition: newPosition)

To one position to the left of the current cursor position

// only if there is a currently selected range
if let selectedRange = textView.selectedTextRange {
    
    // and only if the new position is valid
    if let newPosition = textView.positionFromPosition(selectedRange.start, inDirection: UITextLayoutDirection.Left, offset: 1) {
        
        // set the new position
        textView.selectedTextRange = textView.textRangeFromPosition(newPosition, toPosition: newPosition)
    }
}

To an arbitrary position

Start at the beginning and move 5 characters to the right.

let arbitraryValue: Int = 5
if let newPosition = textView.positionFromPosition(textView.beginningOfDocument, inDirection: UITextLayoutDirection.Right, offset: arbitraryValue) {
    
    textView.selectedTextRange = textView.textRangeFromPosition(newPosition, toPosition: newPosition)
}

Related

Select all text

textView.selectedTextRange = textView.textRangeFromPosition(textView.beginningOfDocument, toPosition: textView.endOfDocument)

Select a range of text

// Range: 3 to 7
let startPosition = textView.positionFromPosition(textView.beginningOfDocument, inDirection: UITextLayoutDirection.Right, offset: 3)
let endPosition = textView.positionFromPosition(textView.beginningOfDocument, inDirection: UITextLayoutDirection.Right, offset: 7)

if startPosition != nil && endPosition != nil {
    textView.selectedTextRange = textView.textRangeFromPosition(startPosition!, toPosition: endPosition!)
}

Insert text at the current cursor position

textView.insertText("Hello")

Notes

• This example originally comes from an adaptation of this Stack Overflow answer.

• This answer uses a text field, but the same concepts apply to UITextView.

• Use textView.becomeFirstResponder() to give focus to the text field and make the keyboard appear.

• See this answer for how to get the text at some range.

Related

• How to Create a Range in Swift (Deals indirectly with the issue of why we have to use selectedTextRange here rather than just selectedRange)

UITextView has extra paddings by default. Sometimes it's annoying especially if you want to measure some text without view instance and place them at some area precisely.

Do this to remove such paddings.

messageTextView.textContainerInset = UIEdgeInsetsZero
messageTextView.textContainer.lineFragmentPadding = 0

Now you can measure text size using NSAttributedString.boundingRectWithSize(...), and resize a UITextView just to fit it to the text.

let budget = getSomeCGSizeBudget()
let text = getSomeAttributedString()
let textSize = text.boundingRectWithSize(budget, options: [.UsesLineFragmentOrigin, .UsesFontLeading], context: nil).size
messageTextView.frame.size = textSize // Just fits.