IOS NSNotification 键盘遮挡问题的解决办法

ios nsnotification 键盘遮挡问题的解决办法

从键盘通知中获得键盘尺寸

键盘尺寸存在于nsnotification中。

1；在adddrinkviewcontroller中添加keyboarddidshow和keyboarddidhide方法

2；在viewwillappear中注册uikeyboarddidshownotification与uikeyboarddidhidenotification。

3；在viewwilldisappear中取消对所有事件的订阅注册

4；在adddrinkviewcontroller中添加一个bool成员，跟踪键盘是否可见的状态。

//
// viewcontroller.h
// scrol
//
// created by gao wuhang on 12-12-5.
// copyright (c) 2012年 gao wuhang. all rights reserved.
//

#import

@interface viewcontroller : uiviewcontroller{
  bool keyboardvisible;
  uiscrollview *scrollview;
}

- (void)keyboarddidshow: (nsnotification*) notif;
- (void)keyboarddidhide: (nsnotification*) notif;

@property (nonatomic, retain) uiscrollview *scrollview;
@end

 
//
// viewcontroller.m
// scrol
//
// created by gao wuhang on 12-12-5.
// copyright (c) 2012年 gao wuhang. all rights reserved.
//

#import "viewcontroller.h"

@interface viewcontroller ()

@end

@implementation viewcontroller

@synthesize scrollview;

- (void)viewwillappear:(bool)animated{
  [super viewwillappear:animated];
  [[nsnotificationcenter defaultcenter] addobserver:self selector:@selector(keyboarddidshow:) name:uikeyboarddidshownotification object:nil];
  [[nsnotificationcenter defaultcenter] addobserver:self selector:@selector(keyboarddidhide:) name:uikeyboarddidhidenotification object:nil];
}

- (void)viewwilldisappear:(bool)animated{
  [[nsnotificationcenter defaultcenter] removeobserver:self];
}

- (void) keyboarddidshow:(nsnotification *)notif {
nslog(@"%@", @"received uikeyboarddidshownotification");
 
if (keyboardvisible) {
nslog(@"%@", @"keyboard is already visible. ignoring notifications.");
return;
}
 
// the keyboard wasn't visible before
nslog(@"resizing smaller for keyboard");
 
// get the origin of the keyboard when it finishes animating
nsdictionary *info = [notif userinfo];
nsvalue *avalue = [info objectforkey:uikeyboardframeenduserinfokey];
 
// get the top of the keyboard in view's coordinate system.
// we need to set the bottom of the scrollview to line up with it
cgrect keyboardrect = [avalue cgrectvalue];
  keyboardrect = [self.view convertrect:keyboardrect fromview:nil];
cgfloat keyboardtop = keyboardrect.origin.y;
  
// resize the scroll view to make room for the keyboard
  cgrect viewframe = self.view.bounds;
viewframe.size.height = keyboardtop - self.view.bounds.origin.y;
 
self.scrollview.frame = viewframe;
keyboardvisible = yes;
}

- (void) keyboarddidhide:(nsnotification *)notif {
nslog(@"%@", @"received uikeyboarddidhidenotification");
 
if (!keyboardvisible) {
nslog(@"%@", @"keyboard already hidden. ignoring notification.");
return;
}
 
// the keyboard was visible
nslog(@"%@", @"resizing bigger with no keyboard");
  
// resize the scroll view back to the full size of our view
self.scrollview.frame = self.view.bounds;
keyboardvisible = no;
}

- (void)viewdidload
{
  scrollview = [[uiscrollview alloc] initwithframe:cgrectmake(0, 0, 320, 460)];
//  scroll.contentsize = cgsizemake(1000, 1000);
  [self.view addsubview:scrollview];
//  uibutton *button = [[uibutton alloc] initwithframe:cgrectmake(100, 100, 100, 100)];
//  [button setbackgroundcolor:[uicolor blackcolor]];
//  [scroll addsubview:button];
  uitextview *textview = [[uitextview alloc]initwithframe:cgrectmake(100, 300, 100, 100)];
  textview.text = @"222";
  textview.font = [uifont systemfontofsize:20];
  [scrollview addsubview:textview];
  [super viewdidload];
  [textview release];

  self.scrollview.contentsize = self.view.frame.size;
// do any additional setup after loading the view, typically from a nib.
}

- (void)dealloc
{
  [scrollview release];
  [super dealloc];
}

- (void)didreceivememorywarning
{
  [super didreceivememorywarning];
  // dispose of any resources that can be recreated.
}

@end

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