以下内容适用于两者UITextField
and UITextView
.
有用的信息
文本字段文本的最开头:
let startPosition: UITextPosition = textField.beginningOfDocument
文本字段文本的最末尾:
let endPosition: UITextPosition = textField.endOfDocument
当前选择的范围:
let selectedRange: UITextRange? = textField.selectedTextRange
获取光标位置
if let selectedRange = textField.selectedTextRange {
let cursorPosition = textField.offset(from: textField.beginningOfDocument, to: selectedRange.start)
print("\(cursorPosition)")
}
设置光标位置
为了设置位置,所有这些方法实际上都是设置一个具有相同开始值和结束值的范围。
到开始
let newPosition = textField.beginningOfDocument
textField.selectedTextRange = textField.textRange(from: newPosition, to: newPosition)
到最后
let newPosition = textField.endOfDocument
textField.selectedTextRange = textField.textRange(from: newPosition, to: newPosition)
到当前光标位置左侧的一个位置
// only if there is a currently selected range
if let selectedRange = textField.selectedTextRange {
// and only if the new position is valid
if let newPosition = textField.position(from: selectedRange.start, offset: -1) {
// set the new position
textField.selectedTextRange = textField.textRange(from: newPosition, to: newPosition)
}
}
到任意位置
从头开始向右移动 5 个字符。
let arbitraryValue: Int = 5
if let newPosition = textField.position(from: textField.beginningOfDocument, offset: arbitraryValue) {
textField.selectedTextRange = textField.textRange(from: newPosition, to: newPosition)
}
Related
选择所有文本
textField.selectedTextRange = textField.textRange(from: textField.beginningOfDocument, to: textField.endOfDocument)
选择文本范围
// Range: 3 to 7
let startPosition = textField.position(from: textField.beginningOfDocument, offset: 3)
let endPosition = textField.position(from: textField.beginningOfDocument, offset: 7)
if startPosition != nil && endPosition != nil {
textField.selectedTextRange = textField.textRange(from: startPosition!, to: endPosition!)
}
在当前光标位置插入文本
textField.insertText("Hello")
Notes
See also
- 如何在 Swift 中创建范围 https://stackoverflow.com/a/35193481/3681880