IOS代码笔记UIView的placeholder的效果

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;

}

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