PlaceholderTextView

 
 效果

 
源码
https://github.com/YouXianMing/UI-Component-Collection 的 PlaceholderTextView

//
//  PlaceholderTextView.h
//  PlaceholderTextView
//
//  Created by YouXianMing on 16/7/18.
//  Copyright © 2016年 YouXianMing. All rights reserved.
//

#import <UIKit/UIKit.h>
@class PlaceholderTextView;

@protocol PlaceholderTextViewDelegate <NSObject>

@optional

/**
 *  Asks the delegate if editing should begin in the specified text view.
 *
 *  @param textView PlaceholderTextView's object.
 *
 *  @return YEStrue if an editing session should be initiated; otherwise, NOfalse to disallow editing.
 */
- (BOOL)placeholderTextViewShouldBeginEditing:(PlaceholderTextView *)textView;

/**
 *  Asks the delegate if editing should stop in the specified text view.
 *
 *  @param textView PlaceholderTextView's object.
 *
 *  @return YEStrue if editing should stop; otherwise, NOfalse if the editing session should continue
 */
- (BOOL)placeholderTextViewShouldEndEditing:(PlaceholderTextView *)textView;

/**
 *  Tells the delegate that editing of the specified text view has begun.
 *
 *  @param textView PlaceholderTextView's object.
 */
- (void)placeholderTextViewDidBeginEditing:(PlaceholderTextView *)textView;

/**
 *  Tells the delegate that editing of the specified text view has ended.
 *
 *  @param textView PlaceholderTextView's object.
 */
- (void)placeholderTextViewDidEndEditing:(PlaceholderTextView *)textView;

/**
 *  Asks the delegate whether the specified text should be replaced in the text view.
 *
 *  @param textView PlaceholderTextView's object.
 *
 *  @return YEStrue if the old text should be replaced by the new text; NOfalse if the replacement operation should be aborted.
 */
- (BOOL)placeholderTextShouldChangeText:(PlaceholderTextView *)textView;

@end

@interface PlaceholderTextView : UIView

/**
 *  PlaceholderTextView's delegate.
 */
@property (nonatomic, weak) id <PlaceholderTextViewDelegate> delegate;

/**
 *  Current string.
 */
@property (nonatomic, strong, readonly) NSString *currentString;

#pragma mark - UITextView related.

/**
 *  The TextView.
 */
@property (nonatomic, strong, readonly) UITextView   *textView;

/**
 *  The textView's containerInset.
 */
@property (nonatomic) UIEdgeInsets  textContainerInset;

#pragma mark - Placeholder related.

/**
 *  Placeholder attributed string.
 */
@property (nonatomic, strong) NSAttributedString *attributedPlaceholder;

/**
 *  PlaceHorderString gap from left.
 */
@property (nonatomic) CGFloat placeHorderLeftEdge;

/**
 *  PlaceHorderString gap from top.
 */
@property (nonatomic) CGFloat placeHorderTopEdge;

#pragma mark - PlaceholderTextView's event.

/**
 * PlaceholderTextView resign first responder.
 */
- (void)placeholderTextViewResignFirstResponder;

/**
 *  PlaceholderTextView become first responder.
 */
- (void)placeholderTextViewbecomeFirstResponder;

@end


//
//  PlaceholderTextView.m
//  PlaceholderTextView
//
//  Created by YouXianMing on 16/7/18.
//  Copyright © 2016年 YouXianMing. All rights reserved.
//

#import "PlaceholderTextView.h"

@interface PlaceholderTextView () <UITextViewDelegate>

@property (nonatomic, strong) UITextField *textField;
@property (nonatomic, strong) UITextView  *textView;
@property (nonatomic, strong) NSString    *currentString;

@end

@implementation PlaceholderTextView

#pragma mark - Frame related method.

- (void)layoutSubviews {

    [super layoutSubviews];
    
    self.textView.frame = self.bounds;
    [self resetPlaceHorderFrame];
}

- (instancetype)initWithFrame:(CGRect)frame {
    
    if (self = [super initWithFrame:frame]) {
        
        self.textField             = [[UITextField alloc] init];
        self.textField.enabled     = NO;
        self.textField.textColor   = [UIColor clearColor];
        [self addSubview:self.textField];
        
        self.textView                 = [[UITextView alloc] initWithFrame:self.bounds];
        self.textView.delegate        = self;
        self.textView.backgroundColor = [UIColor clearColor];
        self.textView.textColor       = [UIColor grayColor];
        [self addSubview:self.textView];
    }
    
    return self;
}

#pragma mark - FirstResponder related.

- (void)placeholderTextViewResignFirstResponder {

    [self.textView resignFirstResponder];
}

- (void)placeholderTextViewbecomeFirstResponder {

    [self.textView becomeFirstResponder];
}

#pragma mark - UITextViewDelegate

- (BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text {
    
    NSString *currentText = [textView.text stringByReplacingCharactersInRange:range withString:text];
    self.textField.text   = currentText;
    self.currentString    = currentText;
    
    if (self.delegate && [self.delegate respondsToSelector:@selector(placeholderTextShouldChangeText:)]) {
        
        return [self.delegate placeholderTextShouldChangeText:self];
        
    } else {
    
        return YES;
    }
}

- (BOOL)textViewShouldBeginEditing:(UITextView *)textView {

    if (self.delegate && [self.delegate respondsToSelector:@selector(placeholderTextViewShouldBeginEditing:)]) {
        
        return [self.delegate placeholderTextViewShouldBeginEditing:self];
        
    } else {
    
        return YES;
    }
}

- (BOOL)textViewShouldEndEditing:(UITextView *)textView {

    if (self.delegate && [self.delegate respondsToSelector:@selector(placeholderTextViewShouldEndEditing:)]) {
        
        return [self.delegate placeholderTextViewShouldEndEditing:self];
        
    } else {
    
        return YES;
    }
}

- (void)textViewDidBeginEditing:(UITextView *)textView {

    if (self.delegate && [self.delegate respondsToSelector:@selector(placeholderTextViewDidBeginEditing:)]) {
        
        [self.delegate placeholderTextViewDidBeginEditing:self];
    }
}

- (void)textViewDidEndEditing:(UITextView *)textView {

    if (self.delegate && [self.delegate respondsToSelector:@selector(placeholderTextViewDidEndEditing:)]) {
        
        [self.delegate placeholderTextViewDidEndEditing:self];
    }
}

#pragma mark - PlaceHorder related

- (void)resetPlaceHorderFrame {

    self.textField.attributedPlaceholder = _attributedPlaceholder;
    [self.textField sizeToFit];
    
    CGRect newFrame      = self.textField.frame;
    newFrame.origin.x    = _placeHorderLeftEdge;
    newFrame.origin.y    = _placeHorderTopEdge;
    self.textField.frame = newFrame;
}

#pragma mark - Setter & Getter

- (void)setTextContainerInset:(UIEdgeInsets)textContainerInset {

    _textContainerInset          = textContainerInset;
    _textView.textContainerInset = textContainerInset;
}

- (void)setPlaceHorderLeftEdge:(CGFloat)placeHorderLeftEdge {

    _placeHorderLeftEdge = placeHorderLeftEdge;
    [self resetPlaceHorderFrame];
}

- (void)setPlaceHorderTopEdge:(CGFloat)placeHorderTopEdge {

    _placeHorderTopEdge = placeHorderTopEdge;
    [self resetPlaceHorderFrame];
}

- (void)setAttributedPlaceholder:(NSAttributedString *)attributedPlaceholder {

    _attributedPlaceholder = attributedPlaceholder;
    [self resetPlaceHorderFrame];
}

@end


//
//  PlaceholderTextView+ConvenientSetup.h
//  PlaceholderTextView
//
//  Created by YouXianMing on 16/7/18.
//  Copyright © 2016年 YouXianMing. All rights reserved.
//

#import "PlaceholderTextView.h"

@interface PlaceholderTextView (ConvenientSetup)

/**
 *  PlaceholderTextView's placeholderString setup.
 *
 *  @param string   The placeholderString.
 *  @param font     Font.
 *  @param color    Color.
 *  @param leftEdge Gap from left.
 *  @param topEdge  Gap from top.
 */
- (void)placeholderString:(NSString *)string font:(UIFont *)font color:(UIColor *)color leftEdge:(CGFloat)leftEdge topEdge:(CGFloat)topEdge;

/**
 *  PlaceholderTextView's textView setup.
 *
 *  @param font           Font.
 *  @param color          Color.
 *  @param containerInset TextContainerInset.
 */
- (void)textViewFont:(UIFont *)font color:(UIColor *)color containerInset:(UIEdgeInsets)containerInset;

/**
 *  Create the InputAccessoryView with the specified heigh.
 *
 *  @param height The view's height.
 *
 *  @return InputAccessoryView.
 */
- (UIView *)createInputAccessoryViewWithViewHeight:(CGFloat)height;

@end


//
//  PlaceholderTextView+ConvenientSetup.m
//  PlaceholderTextView
//
//  Created by YouXianMing on 16/7/18.
//  Copyright © 2016年 YouXianMing. All rights reserved.
//

#import "PlaceholderTextView+ConvenientSetup.h"

@implementation PlaceholderTextView (ConvenientSetup)

- (void)placeholderString:(NSString *)string font:(UIFont *)font color:(UIColor *)color leftEdge:(CGFloat)leftEdge topEdge:(CGFloat)topEdge {
    
    NSParameterAssert(string);
    NSParameterAssert(font);
    NSParameterAssert(color);
    
    NSString                  *placeHorderString = string;
    NSMutableAttributedString *attributeString   = [[NSMutableAttributedString alloc] initWithString:placeHorderString];
    [attributeString addAttribute:NSFontAttributeName value:font range:NSMakeRange(0, placeHorderString.length)];
    [attributeString addAttribute:NSForegroundColorAttributeName value:color range:NSMakeRange(0, placeHorderString.length)];
    
    self.placeHorderLeftEdge   = leftEdge;
    self.placeHorderTopEdge    = topEdge;
    self.attributedPlaceholder = attributeString;
}

- (void)textViewFont:(UIFont *)font color:(UIColor *)color containerInset:(UIEdgeInsets)containerInset {

    self.textView.font      = font;
    self.textView.textColor = color;
    self.textContainerInset = containerInset;
}

- (UIView *)createInputAccessoryViewWithViewHeight:(CGFloat)height {

    UIView *inputAccessoryView         = [[UIView alloc] initWithFrame:CGRectMake(0, 0, [UIScreen mainScreen].bounds.size.width, height)];
    inputAccessoryView.backgroundColor = [UIColor clearColor];
    self.textView.inputAccessoryView   = inputAccessoryView;
    
    return inputAccessoryView;
}

@end


//
//  ViewController.m
//  PlaceholderTextView
//
//  Created by YouXianMing on 16/7/18.
//  Copyright © 2016年 YouXianMing. All rights reserved.
//

#import "ViewController.h"
#import "PlaceholderTextView.h"
#import "PlaceholderTextView+ConvenientSetup.h"

@interface ViewController () <PlaceholderTextViewDelegate> {
    
    PlaceholderTextView *_textView;
}

@end

@implementation ViewController

- (void)viewDidLoad {
    
    [super viewDidLoad];
    
    UIColor *grayColor  = [UIColor grayColor];
    UIColor *textColor  = [[UIColor blackColor] colorWithAlphaComponent:0.95f];
    UIColor *whiteColor = [UIColor whiteColor];
    UIFont  *font_16    = [UIFont systemFontOfSize:16.f];
    
    // Add UITapGestureRecognizer.
    UITapGestureRecognizer *tapGesture = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(gestureEvent)];
    [self.view addGestureRecognizer:tapGesture];
    
    // Create PlaceholderTextView.
    _textView                   = [[PlaceholderTextView alloc] initWithFrame:CGRectMake(0, 20, 320, 180)];
    _textView.layer.borderWidth = 0.5f;
    _textView.delegate          = self;
    [self.view addSubview:_textView];
    
    // Set placeholderString.
    [_textView placeholderString:@"请输入您的评价(少于50字)" font:font_16 color:grayColor leftEdge:19.f topEdge:15.f];
    
    // Set textView.
    [_textView textViewFont:font_16 color:textColor containerInset:UIEdgeInsetsMake(15.f, 15.f, 15.f, 15.f)];
    
    // Create inputAccessoryView.
    UIView *inputAccessoryView         = [_textView createInputAccessoryViewWithViewHeight:40.f];
    inputAccessoryView.backgroundColor = grayColor;
    
    // Setup inputAccessoryView.
    UIButton *button       = [[UIButton alloc] initWithFrame:inputAccessoryView.bounds];
    button.titleLabel.font = [UIFont systemFontOfSize:14.f];
    [button setTitle:@"确定" forState:UIControlStateNormal];
    [button setTitleColor:whiteColor forState:UIControlStateNormal];
    [button setTitleColor:[whiteColor colorWithAlphaComponent:0.5f] forState:UIControlStateHighlighted];
    [button addTarget:self action:@selector(inputAccessoryViewEvent) forControlEvents:UIControlEventTouchUpInside];
    [inputAccessoryView addSubview:button];
}

#pragma mark - Event related.

- (void)inputAccessoryViewEvent {
    
    [_textView placeholderTextViewResignFirstResponder];
}

- (void)gestureEvent {

    [self.view endEditing:YES];
}

#pragma mark - PlaceholderTextViewDelegate

- (BOOL)placeholderTextShouldChangeText:(PlaceholderTextView *)textView {
    
    NSLog(@"--> %@", textView.currentString);
    BOOL result; textView.currentString.length >= 50 ? (result = NO) : (result = YES);
    return result;
}

- (BOOL)placeholderTextViewShouldBeginEditing:(PlaceholderTextView *)textView {
    
    NSLog(@"placeholderTextViewShouldBeginEditing");
    return YES;
}

- (BOOL)placeholderTextViewShouldEndEditing:(PlaceholderTextView *)textView {
    
    NSLog(@"placeholderTextViewShouldEndEditing");
    return YES;
}

- (void)placeholderTextViewDidBeginEditing:(PlaceholderTextView *)textView {
    
    NSLog(@"placeholderTextViewDidBeginEditing");
}

- (void)placeholderTextViewDidEndEditing:(PlaceholderTextView *)textView {
    
    NSLog(@"placeholderTextViewDidEndEditing");
}

#pragma mark - System method.

- (void)viewDidAppear:(BOOL)animated {

    [super viewDidAppear:animated];
    [_textView placeholderTextViewbecomeFirstResponder];
}

   

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