本文实例为大家分享了IOS占位符效果，供大家参考，具体内容如下
一、效果图
二、工程图
三、代码
RootViewController.h
#import <UIKit/UIKit.h> @interface RootViewController : UIViewController <UITextViewDelegate> { UITextView *psTextView; UILabel *pslabel; } @end
RootViewController.m
#import "RootViewController.h" @interface RootViewController () @end @implementation RootViewController - (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil { self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil]; if (self) { // Custom initialization } return self; } - (void)viewDidLoad { [super viewDidLoad]; // Do any additional setup after loading the view. self.title=@"UIView的placeholder的效果"; [self initBackgroundView]; } #pragma -mark -初始化背景图 -(void)initBackgroundView { UIView *backView=[[UIView alloc]initWithFrame:CGRectMake(0, 0, 320, 480)]; [self.view addSubview:backView]; psTextView=[[UITextView alloc]initWithFrame:CGRectMake(10, 70, 280, 200)]; psTextView.text=@""; psTextView.backgroundColor=[UIColor yellowColor]; psTextView.delegate=self; psTextView.scrollEnabled=NO; [backView addSubview:psTextView]; pslabel=[[UILabel alloc]initWithFrame:CGRectMake(15, 140, 280, 20)]; pslabel.text=@"请输入备注信息"; pslabel.textColor=[UIColor grayColor]; pslabel.enabled=NO; pslabel.backgroundColor=[UIColor clearColor]; [backView addSubview:pslabel]; } #pragma -mark -UITextView Delegate - (BOOL)textViewShouldBeginEditing:(UITextView *)textView { return YES; } -(BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text { if (text.length>0) { pslabel.hidden=YES; } if ([text isEqualToString:@"n"]) { [textView resignFirstResponder]; return NO; } return YES; }
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持查字典教程网。
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