UITextView自定义placeholder属性
自定义了个PTextView先上个效果
PTextView.h文件
#import
NS_ASSUME_NONNULL_BEGIN
//返回实时的viewSize
typedef void (^PTextViewSizeChangeBlock)(CGSize viewSize);
@interface PTextView : UITextView
///设置显示的最大行数,默认0 没有滑动效果 viewHeight 随内容改变
///maxLine > 0 viewHeight 最大为设置的最大行数高度 内容超出后有滑动效果
@property (assign, nonatomic) NSInteger maxLine;
//placeholder font 和 PTextView font 一致 默认[UIFont systemFontOfSize:14.f]
@property (strong, nonatomic) UIFont *textFont;
@property (copy, nonatomic) NSString *placeholder;
@property (strong, nonatomic) UIColor *placeholderColor;
///cornerRadius default value 8.f
@property (assign, nonatomic) CGFloat cornerRadius;
@property (copy, nonatomic) PTextViewSizeChangeBlock viewSizeChangeBlock;
@end
NS_ASSUME_NONNULL_END;
PTextView.m文件
#import "PTextView.h"
#define kText_LineSpacing 3.f
@interface PTextView ()
{
CGRect _initFrame;//记录初始frame
CGSize _selfViewSize;
}
@property (strong, nonatomic) UILabel *pLabel;
@end
@implementation PTextView
- (void)awakeFromNib{
[super awakeFromNib];
[self initTextView];
[self initPLabelView];
}
- (instancetype)initWithFrame:(CGRect)frame{
self = [super initWithFrame:frame];
if(self){
_initFrame = self.frame;
_selfViewSize = self.frame.size;
[self initTextView];
[self initPLabelView];
}
return self;
}
- (void)initTextView{
_cornerRadius = 8.f;
_maxLine = 0.f;
self.textFont = [UIFont systemFontOfSize:14.f];
self.delegate = self;
self.layoutManager.allowsNonContiguousLayout = NO;
self.scrollsToTop = NO;
self.scrollEnabled = NO;
self.textContainer.lineFragmentPadding = 0;
self.textContainerInset = UIEdgeInsetsMake(10, _cornerRadius, 5, _cornerRadius);
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(textViewTextDidChange:) name:UITextViewTextDidChangeNotification object:self];
}
- (void)setTextFont:(UIFont *)textFont{
if(textFont){
_textFont = textFont;
self.font = _textFont;
self.pLabel.font = _textFont;
// 字体的行间距
NSMutableParagraphStyle *paragraphStyle = [[NSMutableParagraphStyle alloc] init];
paragraphStyle.lineSpacing = kText_LineSpacing;
NSDictionary *attributes = @{
NSFontAttributeName:_textFont,
NSParagraphStyleAttributeName:paragraphStyle
};
self.typingAttributes = attributes;
}
}
- (void)setCornerRadius:(CGFloat)cornerRadius{
if(_cornerRadius != cornerRadius){
_cornerRadius = cornerRadius;
[self.layer setMasksToBounds:YES];
[self.layer setCornerRadius:cornerRadius];
[self initPLabelView];
}
}
- (void)initPLabelView{
if(_viewSizeChangeBlock){
_viewSizeChangeBlock(_selfViewSize);
}
self.textContainerInset = UIEdgeInsetsMake(10, _cornerRadius, 5, _cornerRadius);
self.frame = CGRectMake(self.frame.origin.x, self.frame.origin.y, _selfViewSize.width, _selfViewSize.height);
self.pLabel.frame = CGRectMake(self.textContainerInset.left, 0.f, self.frame.size.width - (self.textContainerInset.left + self.textContainerInset.right), self.frame.size.height - (self.textContainerInset.top + self.textContainerInset.bottom));
self.pLabel.centerY = self.frame.size.height / 2.f;
self.pLabel.font = _textFont;
self.pLabel.numberOfLines = 0;
self.pLabel.textColor = [UIColor colorWithHexString:@"#BBBBBB"];
[self addSubview:self.pLabel];
}
- (UILabel *)pLabel {
if(!_pLabel){
_pLabel = [[UILabel alloc] init];
}
return _pLabel;
}
- (void)textViewTextDidChange:(NSNotification *)sender{
UITextView *textView = (UITextView *)sender.object;
self.pLabel.hidden = textView.text.length;
CGFloat height = _initFrame.size.height;
if(textView.text.length){
if ([[[UIDevice currentDevice] systemVersion] floatValue] >= 7) {
height = ceilf([self sizeThatFits:self.frame.size].height);
}else{
height = self.contentSize.height;
}
height = ceil(textView.textContainerInset.top + textView.textContainerInset.bottom + height);
}
CGFloat lineH = textView.font.lineHeight + kText_LineSpacing;
CGFloat maxViewH = ceil(textView.textContainerInset.top + textView.textContainerInset.bottom + lineH * self.maxLine);
CGFloat maxViewW = self.frame.size.width;
CGSize viewSize = CGSizeMake(maxViewW, self.maxLine > 0 ? (maxViewH >= height ? height: maxViewH) : height);
_selfViewSize = viewSize;
[self initPLabelView];
if(self.maxLine > 0){
self.scrollEnabled = (height > maxViewH);
[self scrollRangeToVisible:NSMakeRange(textView.selectedRange.location, 1)];
}
NSLog(@"textView.text:%@",textView.text);
}
- (void)setPlaceholder:(NSString *)placeholder{
self.pLabel.text = placeholder;
}
- (void)setPlaceholderColor:(UIColor *)placeholderColor{
self.pLabel.textColor = placeholderColor;
}
//UITextView遵循了UITextInput协议,其中有返回光标frame的方法
//- (CGRect)caretRectForPosition:(UITextPosition *)position
//可以使用自定义的TextView,重写返回光标frame的方法避免光标扩大问题
- (CGRect)caretRectForPosition:(UITextPosition *)position {
CGRect originalRect = [super caretRectForPosition:position];
originalRect.size.height = self.font.lineHeight + 2.f;
originalRect.size.width = 2.f;
return originalRect;
}
- (void)dealloc{
[[NSNotificationCenter defaultCenter] removeObserver:self];
}
@end
直接复制粘贴代码就可以用了,请给点个赞鼓励一哈子!