设计带有placeHolder的TextView

设计带有placeHolder的TextView

效果:

源码：

PlaceholderTextView.h 与 PlaceholderTextView.m

//

//  PlaceholderTextView.h

//  YXTextView

//

//  Created by YouXianMing on 14/12/23.

//  Copyright (c) 2014年 YouXianMing. All rights reserved.

//

#import <UIKit/UIKit.h>

@interface PlaceholderTextView : UIView

// 获取的字符串

@property (nonatomic, strong, readonly) NSString *string;

// textView

@property (nonatomic, strong) UITextView  *textView;

// 占位字符

@property (nonatomic, strong) NSString    *placeHolderString;

// 文本边缘留白

@property(nonatomic, assign) UIEdgeInsets  textContainerInset;

// 颜色设置

@property (nonatomic, strong) UIColor     *editTextColor;

@property (nonatomic, strong) UIColor     *placeHolderColor;

// 返回键是否用来做取消第一响应者

@property (nonatomic, assign) BOOL         returnButtonToResignFirstResponder;

// 取消第一响应者

- (void)resignTextViewFirstResponder;

@end

//

//  PlaceholderTextView.m

//  YXTextView

//

//  Created by YouXianMing on 14/12/23.

//  Copyright (c) 2014年 YouXianMing. All rights reserved.

//

#import "PlaceholderTextView.h"

@interface PlaceholderTextView ()<UITextViewDelegate>

@property (nonatomic, strong) NSString *string;

@end

@implementation PlaceholderTextView

- (instancetype)initWithFrame:(CGRect)frame

{

    self = [super initWithFrame:frame];

    if (self) {

        [self createTextView];

    }

    return self;

}

- (void)createTextView {

    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];

}

#pragma mark - 代理方法

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

    // 设置编辑状态文字颜色

    textView.textColor = (self.editTextColor == nil ? [UIColor blackColor] : self.editTextColor);

    // 如果文字为placeHolder文字

    if ([textView.text isEqualToString:self.placeHolderString]) {

        textView.text = @"";

    }

    return YES;

}

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

    // 如果长度为0，则显示placeHolder文字

    if (textView.text.length == ) {

        textView.text      = self.placeHolderString;

        textView.textColor = (self.placeHolderColor == nil ? [UIColor grayColor] : self.placeHolderColor);

    }

    return YES;

}

- (BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text {

    if (_returnButtonToResignFirstResponder == YES) {

        if ([text isEqualToString:@"\n"]) {

            [textView resignFirstResponder];

            return NO;

        }

    }

    return YES;

}

- (void)resignTextViewFirstResponder {

    [self.textView resignFirstResponder];

}

#pragma mark - 重写setter，getter方法

@synthesize string = _string;

- (NSString *)string {

    if ([self.textView.text isEqualToString:self.placeHolderString]) {

        return @"";

    } else {

        return self.textView.text;

    }

}

@synthesize placeHolderColor = _placeHolderColor;

- (void)setPlaceHolderColor:(UIColor *)placeHolderColor {

    _placeHolderColor       = placeHolderColor;

    self.textView.textColor = _placeHolderColor;

}

- (UIColor *)placeHolderColor {

    return _placeHolderColor;

}

@synthesize placeHolderString = _placeHolderString;

- (void)setPlaceHolderString:(NSString *)placeHolderString {

    _placeHolderString = placeHolderString;

    _textView.text     = placeHolderString;

}

- (NSString *)placeHolderString {

    return _placeHolderString;

}

@synthesize textContainerInset = _textContainerInset;

- (void)setTextContainerInset:(UIEdgeInsets)textContainerInset {

    _textContainerInset          = textContainerInset;

    _textView.textContainerInset = textContainerInset;

}

- (UIEdgeInsets)textContainerInset {

    return _textContainerInset;

}

@end

控制器源码：

//

//  ViewController.m

//  YXTextView

//

//  Created by YouXianMing on 14/12/23.

//  Copyright (c) 2014年 YouXianMing. All rights reserved.

//

#import "ViewController.h"

#import "PlaceholderTextView.h"

@interface ViewController ()

@end

@implementation ViewController

- (void)viewDidLoad {

    [super viewDidLoad];

    self.view.backgroundColor = [UIColor blackColor];

    PlaceholderTextView *textView = [[PlaceholderTextView alloc] initWithFrame:CGRectMake(-, , , )];

    [self.view addSubview:textView];

    textView.layer.borderWidth  = .f;

    textView.layer.borderColor  = [UIColor purpleColor].CGColor;

    textView.returnButtonToResignFirstResponder = YES;

    textView.textView.font      = [UIFont fontWithName:@"HelveticaNeue-Thin" size:.f];

    textView.placeHolderColor   = [UIColor cyanColor];

    textView.editTextColor      = [UIColor redColor];

    textView.textContainerInset = UIEdgeInsetsMake(, , , );

    textView.placeHolderString  = @"Input your name, please...";

}

@end

需要注意的一些细节：