评论 TextView 工具类 GTCommentManager ：

#import <Foundation/Foundation.h>

NS_ASSUME_NONNULL_BEGIN

@interface GTCommentManager : NSObject

+ (GTCommentManager *)sharedManager;

- (void)showCommentView;

@end

NS_ASSUME_NONNULL_END

#import "GTCommentManager.h"
#import <UIKit/UIKit.h>
#import "GTScreen.h"

@interface GTCommentManager ()<UITextViewDelegate>

@property(nonatomic, strong, readwrite) UIView *backgroundView;
@property(nonatomic, strong, readwrite) UITextView *textView;

@end

@implementation GTCommentManager

+ (GTCommentManager *)sharedManager{
    static GTCommentManager *manager;
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        manager = [[GTCommentManager alloc] init];
    });
    return manager;
}

- (instancetype)init{
    self = [super init];
    if (self) {
        _backgroundView = [[UIView alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
        _backgroundView.backgroundColor = [UIColor colorWithRed:0 green:0 blue:0 alpha:0.8];
        [_backgroundView addGestureRecognizer:[[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(_tapBackground)]];
        
        [_backgroundView addSubview:({
            _textView = [[UITextView alloc] initWithFrame:CGRectMake(0, _backgroundView.bounds.size.height, SCREEN_WIDTH, UI(100))];
            _textView.backgroundColor = [UIColor whiteColor];
            _textView.layer.borderColor = [UIColor lightGrayColor].CGColor;
            _textView.layer.borderWidth = 5.f;
            _textView.delegate = self;
            _textView;
        })];
        
        [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(_doTextViewAnimationWithNotification:) name:UIKeyboardWillChangeFrameNotification object:nil];
    }
    return self;
}

- (void)dealloc{
    [[NSNotificationCenter defaultCenter]  removeObserver:self];
}

#pragma mark -

- (void)showCommentView{
    [[UIApplication sharedApplication].keyWindow addSubview:_backgroundView];
    [_textView becomeFirstResponder];
}

#pragma mark -

- (void)_tapBackground{
    [_textView resignFirstResponder];
    [_backgroundView removeFromSuperview];
}

- (void)_doTextViewAnimationWithNotification:(NSNotification *)noti{
    
    CGFloat duration = [[noti.userInfo objectForKey:UIKeyboardAnimationDurationUserInfoKey] floatValue];
    CGRect keyboardFrame = [[noti.userInfo objectForKey:UIKeyboardFrameEndUserInfoKey] CGRectValue];
    
    if (keyboardFrame.origin.y >= SCREEN_HEIGHT) {
        // 键盘收起
        [UIView animateWithDuration:duration animations:^{
            self.textView.frame = CGRectMake(0, self.backgroundView.bounds.size.height, SCREEN_WIDTH, UI(100));
        }];
    }else{
        self.textView.frame = CGRectMake(0, self.backgroundView.bounds.size.height, SCREEN_WIDTH, UI(100));
        [UIView animateWithDuration:duration animations:^{
            self.textView.frame = CGRectMake(0, self.backgroundView.bounds.size.height - keyboardFrame.size.height - UI(100), SCREEN_WIDTH, UI(100));
        }];
    }
}

#pragma mark -

//delegate

@end

使用方法，只需要调用下面方法就行：

#pragma mark -
- (void)_showCommentView{
    [[GTCommentManager sharedManager] showCommentView];
}

效果：

show comment