TextView的封装和自定义

实现的效果如下:

 #import <UIKit/UIKit.h>

 @interface CustomTextView : UITextView

 @property (nonatomic , strong) UILabel *placeHolderLabel; // 默认的Label
 @property (nonatomic , strong) NSString *placeholderStr;  // 默认的文字显示
 @property (nonatomic , strong) UIColor *palceHolderColor;  //默认文字显示的颜色
 @end

 #import "CustomTextView.h"

 @implementation CustomTextView

 - (instancetype)initWithFrame:(CGRect)frame{

     self = [super initWithFrame:frame];
     if (self) {
         [self setPlaceholderStr:@""];
         [self setPalceHolderColor:[UIColor lightGrayColor]];

     }
     return self;
 }

 // 接收数据

 - (void)setPlaceholderStr:(NSString *)placeholderStr{

     if (_placeholderStr != placeholderStr) {

         _placeholderStr = placeholderStr;

         // 防止创建多个

         [self.placeHolderLabel removeFromSuperview];
         self.placeHolderLabel = nil;

         // 重新绘制  会调用drawRect方法

         [self setNeedsDisplay];
     }
 }

 - (void)drawRect:(CGRect)rect{

     [super drawRect:rect];
     if (self.placeholderStr.length > ) {

         if (_placeHolderLabel == nil) {
             _placeHolderLabel = [[UILabel alloc]initWithFrame:CGRectMake(, , self.bounds.size.width - , )];
             _placeHolderLabel.lineBreakMode = NSLineBreakByWordWrapping;
             _placeHolderLabel.numberOfLines = ;
             _placeHolderLabel.font = self.font;
             _placeHolderLabel.backgroundColor = [UIColor clearColor];
             _placeHolderLabel.textColor = self.palceHolderColor;
             _placeHolderLabel.alpha = ;
             _placeHolderLabel.tag = ;
             [self addSubview:_placeHolderLabel];
         }
         _placeHolderLabel.text = self.placeholderStr;

         //自适应宽高
         [_placeHolderLabel sizeToFit];

     }
     if ([[self text] length] ==  && [[self placeholderStr] length] >) {
         [[self viewWithTag:] setAlpha:1.0];
     }

 }

使用如下:

 #import "Button1Controller.h"

 #import "CustomTextView.h"

 #define kTextBorderColor     RGBCOLOR(227,224,216)
 #undef  RGBCOLOR
 #define RGBCOLOR(r,g,b) [UIColor colorWithRed:r/255.0 green:g/255.0 blue:b/255.0 alpha:1]

 @interface Button1Controller ()<UITextViewDelegate>

 @property (nonatomic,strong) CustomTextView *textView;
 @property (nonatomic , strong) UIButton *commitButton;

 @end

 @implementation Button1Controller

 - (void)viewDidLoad {
     [super viewDidLoad];

     self.view.backgroundColor = [UIColor colorWithRed:229.0/ green:229.0/ blue:229.0/ alpha:1.0f];

     [self.view addSubview:self.textView];

     self.automaticallyAdjustsScrollViewInsets = NO;

     [self.view addSubview:self.commitButton];

 }

 // TextView

 - (CustomTextView *)textView{

     if (!_textView) {
         _textView = [[CustomTextView alloc]initWithFrame:CGRectMake(, , self.view.frame.size.width - , )];
         _textView.backgroundColor = [UIColor whiteColor];
         _textView.delegate = self;
         _textView.font = [UIFont systemFontOfSize:.f];
         _textView.textColor = [UIColor blackColor];
         _textView.textAlignment = NSTextAlignmentLeft;
         _textView.editable = YES;
         _textView.layer.cornerRadius = 4.0f;
         _textView.layer.borderColor = kTextBorderColor.CGColor;
         _textView.layer.borderWidth = 0.5;
         _textView.palceHolderColor = RGBCOLOR(0x89, 0x89, 0x89);
         _textView.placeholderStr = @"请输入您的宝贵意见，我们会尽快处理!";
     }

     return _textView;

 }

 // CommutButton

 - (UIButton *)commitButton{

     if (!_commitButton) {
         _commitButton = [UIButton buttonWithType:UIButtonTypeCustom];
         _commitButton.layer.cornerRadius = 2.0f;
         _commitButton.frame = CGRectMake(, CGRectGetMaxY(self.textView.frame)+, self.view.frame.size.width - , );
         _commitButton.backgroundColor = [self colorWithRGBHex:0x60cdf8];
         [_commitButton setTitle:@"提交" forState:UIControlStateNormal];
         [_commitButton addTarget:self action:@selector(sendFeedBack) forControlEvents:UIControlEventTouchUpInside];
     }

     return _commitButton;

 }

 // 16进制转颜色

 - (UIColor *)colorWithRGBHex:(UInt32)hex
 {
     int r = (hex >> ) & 0xFF;
     int g = (hex >> ) & 0xFF;
     int b = (hex) & 0xFF;

     return [UIColor colorWithRed:r / 255.0f
                            green:g / 255.0f
                             blue:b / 255.0f
                            alpha:1.0f];
 }

 // 提交按钮被点击

 - (void)sendFeedBack{

     NSLog(@"提交...");

 }

 // 判断如果用户输入\n,则收回键盘

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

     if ([text isEqualToString:@"\n"]) {
         [textView resignFirstResponder];
         return NO;
     }
     return YES;
 }

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

     self.textView.placeholderStr = @"";
 }