本文實例為大家分享了ios占位符效果，供大家參考，具體內容如下
一、效果圖
二、工程圖
三、代碼
rootviewcontroller.h
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#import <uikit/uikit.h>@interface rootviewcontroller : uiviewcontroller<uitextviewdelegate>{ uitextview *pstextview; uilabel *pslabel;}@end |
rootviewcontroller.m
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#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 initbackgroundview];}#pragma -mark -初始化背景圖-(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=@"請輸入備注信息"; 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內容，希望對大家的學習有所幫助，也希望大家多多支持服務器之家。
