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
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#import <uikit/uikit.h>
@interface rootviewcontroller : uiviewcontroller
<uitextviewdelegate>
{
uitextview *pstextview;
uilabel *pslabel;
}
@end
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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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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服务器之家。