JKSwiftExtension，测试用例在 UITextViewExtensionViewController.swift 里面
目录：
1、基本的扩展 (使用runtime添加属性)
一、基本的扩展 (使用runtime添加属性)
// MARK: 提示：如果你想对textView.text直接赋值。请在设置属性之前进行，否则影响计算
// MARK:- 一、基本的扩展 (使用runtime添加属性)
public extension UITextView {
// MARK: 1.1、设置占位符
/// 设置占位符
var placeholder: String? {
set {
objc_setAssociatedObject(self, UITextView.RuntimeKey.placeholder, newValue, .OBJC_ASSOCIATION_COPY_NONATOMIC)
initPlaceholder(placeholder!)
}
get {
return objc_getAssociatedObject(self, UITextView.RuntimeKey.placeholder) as? String
}
}
// MARK: 1.2、限制的字数
/// 限制的字数
var limitLength: NSNumber? {
set {
objc_setAssociatedObject(self, UITextView.RuntimeKey.limitLength, newValue, .OBJC_ASSOCIATION_COPY_NONATOMIC)
initWordCountLabel(limitLength!)
}
get {
return objc_getAssociatedObject(self, UITextView.RuntimeKey.limitLength) as? NSNumber
}
}
// MARK: 1.3、限制行数
/// 限制的行数
var limitLines: NSNumber? {
set {
objc_setAssociatedObject(self, UITextView.RuntimeKey.limitLines, newValue, .OBJC_ASSOCIATION_COPY_NONATOMIC)
NotificationCenter.default.addObserver(self, selector: #selector(limitLengthEvent), name: UITextView.textDidChangeNotification, object: self)
}
get {
return objc_getAssociatedObject(self, UITextView.RuntimeKey.limitLines) as? NSNumber
}
}
// MARK: 1.4、默认文本字体的大小
/// 默认文本字体的大小
var placeholdFont: UIFont? {
set {
objc_setAssociatedObject(self, UITextView.RuntimeKey.placeholdFont, newValue, .OBJC_ASSOCIATION_RETAIN_NONATOMIC)
if self.placeholderLabel != nil {
self.placeholderLabel?.font = placeholdFont
}
}
get {
return objc_getAssociatedObject(self, UITextView.RuntimeKey.placeholdFont) as? UIFont == nil ? UIFont.systemFont(ofSize: 13) : objc_getAssociatedObject(self, UITextView.RuntimeKey.placeholdFont) as? UIFont
}
}
// MARK: 1.5、默认文本的颜色
/// 默认文本的颜色
var placeholdColor: UIColor? {
set {
objc_setAssociatedObject(self, UITextView.RuntimeKey.placeholdColor, newValue, .OBJC_ASSOCIATION_RETAIN_NONATOMIC)
if self.placeholderLabel != nil {
self.placeholderLabel?.textColor = placeholdColor
}
}
get {
return objc_getAssociatedObject(self, UITextView.RuntimeKey.placeholdColor) as? UIColor == nil ? UIColor.lightGray : objc_getAssociatedObject(self, UITextView.RuntimeKey.placeholdColor) as? UIColor
}
}
// MARK: 1.6、设置 默认文本的Origin
/// 设置 默认文本的Origin
var placeholderOrigin: CGPoint? {
set {
objc_setAssociatedObject(self, UITextView.RuntimeKey.placeholderOrigin, newValue, .OBJC_ASSOCIATION_RETAIN_NONATOMIC)
if self.placeholderLabel != nil && placeholderOrigin != nil {
self.placeholderLabel?.frame.origin = placeholderOrigin!
}
}
get {
return objc_getAssociatedObject(self, UITextView.RuntimeKey.placeholderOrigin) as? CGPoint == nil ? CGPoint(x: 7, y: 7) : objc_getAssociatedObject(self, UITextView.RuntimeKey.placeholderOrigin) as? CGPoint
}
}
// MARK: 1.7、是否自动变化高度
/// 是否自动变化高度
var autoHeight: Bool? {
set {
objc_setAssociatedObject(self, UITextView.RuntimeKey.autoHeight, newValue, .OBJC_ASSOCIATION_RETAIN_NONATOMIC)
}
get {
return objc_getAssociatedObject(self, UITextView.RuntimeKey.autoHeight) as? Bool == nil ? false : objc_getAssociatedObject(self, UITextView.RuntimeKey.autoHeight) as? Bool
}
}
}
// MARK:- fileprivate 私有的内容
extension UITextView {
fileprivate struct RuntimeKey {
static let placeholder: UnsafeRawPointer! = UnsafeRawPointer.init(bitPattern: "PLACEHOLDEL".hashValue)
static let limitLength: UnsafeRawPointer! = UnsafeRawPointer.init(bitPattern: "LIMITLENGTH".hashValue)
static let limitLines: UnsafeRawPointer! = UnsafeRawPointer.init(bitPattern: "LIMITLINES".hashValue)
static let placeholderLabel: UnsafeRawPointer! = UnsafeRawPointer.init(bitPattern: "PLACEHOLDELABEL".hashValue)
static let wordCountLabel: UnsafeRawPointer! = UnsafeRawPointer.init(bitPattern: "WORDCOUNTLABEL".hashValue)
static let placeholdFont: UnsafeRawPointer! = UnsafeRawPointer.init(bitPattern: "PLACEHOLDFONT".hashValue)
static let placeholdColor: UnsafeRawPointer! = UnsafeRawPointer.init(bitPattern: "PLACEHOLDCOLOR".hashValue)
static let limitLabelColor: UnsafeRawPointer! = UnsafeRawPointer.init(bitPattern: "LIMITLABLECOLOR".hashValue)
static let autoHeight: UnsafeRawPointer! = UnsafeRawPointer.init(bitPattern: "AUTOHEIGHT".hashValue)
static let oldFrame: UnsafeRawPointer! = UnsafeRawPointer.init(bitPattern: "LODFRAME".hashValue)
static let placeholderOrigin: UnsafeRawPointer! = UnsafeRawPointer.init(bitPattern: "PLACEHOLDERORIGIN".hashValue)
// ...其他Key声明
}
/// 最初的 frame
fileprivate var oldFrame: CGRect? {
set {
objc_setAssociatedObject(self, UITextView.RuntimeKey.oldFrame, newValue, .OBJC_ASSOCIATION_RETAIN_NONATOMIC)
}
get {
return objc_getAssociatedObject(self, UITextView.RuntimeKey.oldFrame) as? CGRect
}
}
/// 文字数量
fileprivate var wordCountLabel: UILabel? {
set {
objc_setAssociatedObject(self, UITextView.RuntimeKey.wordCountLabel, newValue, .OBJC_ASSOCIATION_RETAIN_NONATOMIC)
}
get {
return objc_getAssociatedObject(self, UITextView.RuntimeKey.wordCountLabel) as? UILabel
}
}
/// 默认文本
fileprivate var placeholderLabel: UILabel? {
set {
objc_setAssociatedObject(self, UITextView.RuntimeKey.placeholderLabel, newValue, .OBJC_ASSOCIATION_RETAIN_NONATOMIC)
}
get {
return objc_getAssociatedObject(self, UITextView.RuntimeKey.placeholderLabel) as? UILabel
}
}
/// 占位符
/// - Parameter placeholder: 占位符
fileprivate func initPlaceholder(_ placeholder: String) {
NotificationCenter.default.addObserver(self, selector: #selector(textChange(_:)), name: UITextView.textDidChangeNotification, object: self)
self.placeholderLabel = UILabel()
placeholderLabel?.font = self.placeholdFont
placeholderLabel?.text = placeholder
placeholderLabel?.numberOfLines = 0
placeholderLabel?.lineBreakMode = .byWordWrapping
placeholderLabel?.textColor = self.placeholdColor
let rect = placeholder.boundingRect(with: CGSize(width: self.jk.width - placeholderOrigin!.x * 2, height: CGFloat(MAXFLOAT)), options: .usesLineFragmentOrigin, attributes: [NSAttributedString.Key.font : self.placeholdFont!], context: nil)
placeholderLabel?.frame = CGRect(x: placeholderOrigin!.x, y: placeholderOrigin!.y, width: self.jk.width - placeholderOrigin!.x * 2, height: rect.size.height)
addSubview(self.placeholderLabel!)
oldFrame = self.frame
placeholderLabel?.isHidden = self.text.count > 0 ? true : false
}
/// 字数限制
/// - Parameter limitLength: 字数限制
fileprivate func initWordCountLabel(_ limitLength : NSNumber) {
NotificationCenter.default.addObserver(self, selector: #selector(limitLengthEvent), name: UITextView.textDidChangeNotification, object: self)
if wordCountLabel != nil {
wordCountLabel?.removeFromSuperview()
}
wordCountLabel = UILabel(frame: CGRect(x: 0, y: self.frame.size.height - 20, width: self.frame.size.width - 10, height: 20))
wordCountLabel?.textAlignment = .right
wordCountLabel?.textColor = self.textColor
wordCountLabel?.font = self.font
if self.text.count > limitLength.intValue {
self.text = (self.text as NSString).substring(to: limitLength.intValue)
}
wordCountLabel?.text = "\(self.text.count)/\(limitLength)"
addSubview(wordCountLabel!)
self.contentInset = UIEdgeInsets(top: 0, left: 0, bottom: 20, right: 0)
}
/// 动态监听
/// - Parameter notification: 动态监听
@objc fileprivate func textChange(_ notification : Notification) {
let textView = notification.object as! UITextView;
self.text = textView.text;
if placeholder != nil {
placeholderLabel?.isHidden = true
if self.text.count == 0 {
self.placeholderLabel?.isHidden = false
}
}
if limitLength != nil {
var wordCount = self.text.count
if wordCount > (limitLength?.intValue)! {
wordCount = (limitLength?.intValue)!
}
let limit = limitLength!.stringValue
wordCountLabel?.text = "\(wordCount)/\(limit)"
}
if autoHeight == true {
let size = getStringPlaceSize(self.text, textFont: self.font!)
UIView.animate(withDuration: 0.15) { [weak self] in
guard let weakSelf = self else { return }
JKPrint("autoHeight的CGPoint=========\(weakSelf.placeholderOrigin!)")
weakSelf.frame = CGRect(x: weakSelf.jk.x, y: weakSelf.jk.y, width: weakSelf.jk.width, height: size.height + weakSelf.placeholderOrigin!.y * 2 < weakSelf.oldFrame!.height ? weakSelf.oldFrame!.height : size.height + weakSelf.placeholderOrigin!.y * 2)
}
}
}
@objc fileprivate func limitLengthEvent() {
if limitLength != nil {
if self.text.count > (limitLength?.intValue)! && limitLength != nil {
self.text = (self.text as NSString).substring(to: (limitLength?.intValue)!)
JKPrint("Maximum number of words");
}
} else {
//行数限制
if (limitLines != nil) {
var size = getStringPlaceSize(self.text, textFont: self.font!)
let height = self.font!.lineHeight * CGFloat(limitLines!.floatValue)
if (size.height > height) {
JKPrint("Maximum number of lines");
//循环计算当前高度可以存放的字符
while size.height > height {
self.text = (self.text as NSString).substring(to: self.text.count - 1)
size = getStringPlaceSize(self.text, textFont: self.font!)
}
}
}
}
}
@objc fileprivate func getStringPlaceSize(_ string : String, textFont : UIFont) -> CGSize {
///计算文本高度
let font : UIFont = textFont
let attribute = [NSAttributedString.Key.font : font];
let options = NSStringDrawingOptions.usesLineFragmentOrigin
let size = string.boundingRect(with: CGSize(width: self.contentSize.width-10, height: CGFloat.greatestFiniteMagnitude), options: options, attributes: attribute, context: nil).size
return size
}
open override func canPerformAction(_ action: Selector, withSender sender: Any?) -> Bool {
if action == #selector(UIResponderStandardEditActions.paste(_:))
|| action == #selector(UIResponderStandardEditActions.select(_:))
|| action == #selector(UIResponderStandardEditActions.selectAll(_:))
|| action == #selector(UIResponderStandardEditActions.copy(_:))
|| action == #selector(UIResponderStandardEditActions.cut(_:))
|| action == #selector(UIResponderStandardEditActions.delete(_:))
{
OperationQueue.main.addOperation {
UIMenuController.shared.setMenuVisible(false, animated: false)
}
self.selectedRange = NSRange.init(location: 0, length: 0)
return false
}
return super.canPerformAction(action, withSender: sender)
}
}
