自定义UITextView

自定义UITextView,带有placeholeder,可以设置placeholeder文字的大小和颜色。

如图:

集成简单,只需在所用到的控制器中导入YMTextView即可,下面是示例代码:

在ViewController.m中

#import "ViewController.h"#import "YMTextView.h"@interface ViewController ()//输入控件@property (nonatomic, weak) YMTextView *textView;@end@implementation ViewController- (void)viewDidLoad {    [super viewDidLoad];    [self setupLabel];    //设置输入控件    [self setupTextView];}-(void)setupLabel {    UILabel *titleLabel = [[UILabel alloc] initWithFrame:CGRectMake(0, 40, self.view.frame.size.width, 44)];    titleLabel.text = @"自定义textView控件";    titleLabel.textAlignment = NSTextAlignmentCenter;    titleLabel.textColor = [UIColor blackColor];    [self.view addSubview:titleLabel];}//添加输入控件-(void)setupTextView {    // 在这个控制器中，textView的contentInset.top默认会等于64    YMTextView *textView = [[YMTextView alloc] init];    textView.frame = CGRectMake(0, 100, self.view.frame.size.width, 200);    textView.backgroundColor = [UIColor lightGrayColor];    textView.font = [UIFont systemFontOfSize:15];    //设置占位文字    textView.placeholder = @"这里是占位文字...";    //设置占位文字颜色//    textView.placeholderColor = [UIColor redColor];    [self.view addSubview:textView];    self.textView = textView;    //监听通知    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(textDidChange) name:UITextViewTextDidChangeNotification object:textView];}/** *  监听文字改变 */-(void)textDidChange {    if (self.textView.hasText) {        NSLog(@"文字发生改变----%@",self.textView.text);    }}-(void)dealloc {    //移除通知    [[NSNotificationCenter defaultCenter] removeObserver:self];}- (void)didReceiveMemoryWarning {    [super didReceiveMemoryWarning];    // Dispose of any resources that can be recreated.}@end

在YMTextView.h中:

#import <UIKit/UIKit.h>@interface YMTextView : UITextView/** *  占位文字 */@property (nonatomic, copy) NSString *placeholder;/** *  占位文字颜色 */@property (nonatomic, strong) UIColor *placeholderColor;@end

在YMTextView.m中:

#import "YMTextView.h"@implementation YMTextView- (instancetype)initWithFrame:(CGRect)frame{    self = [super initWithFrame:frame];    if (self) {        // 当UITextView的文字发生改变时，UITextView自己会发出一个UITextViewTextDidChangeNotification通知        [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(textDidChange) name:UITextViewTextDidChangeNotification object:self];    }    return self;}/** *  监听文字改变 */-(void)textDidChange {    //重绘    [self setNeedsDisplay];}-(void)setPlaceholder:(NSString *)placeholder {    _placeholder = placeholder;    // setNeedsDisplay会在下一个消息循环时刻，调用drawRect:    [self setNeedsDisplay];}-(void)setText:(NSString *)text {    [super setText:text];    // setNeedsDisplay会在下一个消息循环时刻，调用drawRect:    [self setNeedsDisplay];}-(void)setFont:(UIFont *)font {    [super setFont:font];    // setNeedsDisplay会在下一个消息循环时刻，调用drawRect:    [self setNeedsDisplay];}- (void)drawRect:(CGRect)rect {    // 如果有输入文字，就直接返回，不画占位文字    if (self.hasText) return;    //设置文字属性    NSMutableDictionary *attributes = [NSMutableDictionary dictionary];    attributes[NSFontAttributeName] = self.font;    attributes[NSForegroundColorAttributeName] = self.placeholderColor ? self.placeholderColor : [UIColor grayColor];    //画文字    CGFloat x = 5;    CGFloat width = rect.size.width -2 * x;    CGFloat y = 8;    CGFloat height = rect.size.height - 2 * y;    CGRect placeholderRect = CGRectMake(x, y, width, height);    [self.placeholder drawInRect:placeholderRect withAttributes:attributes];}-(void)dealloc {    [[NSNotificationCenter defaultCenter] removeObserver:self];}@end

代码地址