小题大做
[[NSNotificationCenter defaultCenter]postNotificationName:@"RequestData" object:[NSNumber numberWithInteger:self.PraiseNum] userInfo:self.myDic];
b、仅仅通知
[[NSNotificationCenter defaultCenter]postNotificationName:@"唯一通知标识" object:nil];
B，接收通知
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(reloadRuestData:) name:@"RequestData" object:nil];
- (void)reloadRuestData:(NSNotification *)aNotification
{
NSInteger Pint = [aNotification.object integerValue];
NSDictionary *DD = aNotification.userInfo;
}
2.得到当前点击的这个cell
PostThreeImageCell *cell = (PostThreeImageCell *)btn.superview.superview.superview.superview;（根据自己这个控件所在的层。添加或者减少superview。）
NSIndexPath *indexPost = [_tableView indexPathForCell:cell];
3.正则判断字符格式
//判断字符串的格式，只能由字母、数字、下划线组成，并且只能以字母开头
NSString *str = @"^[a-zA-Z]\\w*$";
NSPredicate *pred = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", str];
BOOL isMatch = [pred evaluateWithObject:txt1.text];
if (isMatch==NO) {
alert = [[UIAlertView alloc]initWithTitle:@"提示" message:@"字符只能由字母、数字、下划线组成，并且由字母开头。" delegate:self cancelButtonTitle:nil otherButtonTitles:@"OK", nil];
[alert show];
}else{
NSLog(@"格式正确");
}
4.根据传入的时间字符串判断时间距当前处于什么时刻
/*
判断时间的显示格式
今天就显示：时分
昨天就显示：昨天
这周就显示：星期几
这周以前：年月日
*/
-(NSString *)compareDate:(NSString *)time{
NSLog(@"time si %@",time);
NSDateFormatter *dateFormat = [[NSDateFormatter alloc]init];
[dateFormat setDateFormat:@"yyyy-MM-dd HH:mm:ss.SSS"];
NSDate *date = [dateFormat dateFromString:time];
int timeIntervar=[date timeIntervalSinceNow];
NSTimeInterval secondsPerDay = 24 * 60 * 60;
NSDate *today = [[NSDate alloc] init];
NSDate *tomorrow, *yesterday;
tomorrow = [today dateByAddingTimeInterval: secondsPerDay];
yesterday = [today dateByAddingTimeInterval: -secondsPerDay];
NSString * todayString = [[today description] substringToIndex:10];
NSString * yesterdayString = [[yesterday description] substringToIndex:10];
NSString * tomorrowString = [[tomorrow description] substringToIndex:10];
NSString * dateString = [[date description] substringToIndex:10];
//判断周几
NSCalendar* calendar = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
NSDateComponents* components = [[NSDateComponents alloc] init];
NSInteger unitFlags = NSYearCalendarUnit |
NSMonthCalendarUnit |
NSDayCalendarUnit |
NSWeekdayCalendarUnit |
NSHourCalendarUnit |
NSMinuteCalendarUnit |
NSSecondCalendarUnit;
NSLog(@"date is %@",date);
components = [calendar components:unitFlags fromDate:date];
NSUInteger weekday = [components weekday];
NSLog(@"weekday si %d",weekday);
//判断是今天还是昨天
if ([dateString isEqualToString:todayString])
{
//今天
[dateFormat setDateFormat:@"HH:mm"];//设定时间格式
return [dateFormat stringFromDate:date];
} else if ([dateString isEqualToString:yesterdayString])
{
return @"昨天";
}else if ([dateString isEqualToString:tomorrowString])
{
return @"明天";
}
else
{
//判断是否是一周前
if(-timeIntervar>604800){
[dateFormat setDateFormat:@"yyyy-MM-dd"];//设定时间格式
NSString *dateString = [dateFormat stringFromDate:date];
return dateString;
}else{
//return dateString;
NSLog(@"weekday si %d",weekday);
//判断周几
switch (weekday) {
case 2:
return @"星期一";
break;
case 3:
return @"星期二";
break;
case 4:
return @"星期三";
break;
case 5:
return @"星期四";
break;
case 6:
return @"星期五";
break;
case 7:
return @"星期六";
break;
case 1:
return @"星期日";
break;
default:
break;
}
}
}
5.获取设备唯一编号
+ (NSString *)getDeviceId
{
NSString *udid = [UIDevice uniqueDeviceIdentifier];
NSLog(@"udid in keychain %@", udid);
return udid;
}
6.键盘出现时，向上移动view，防止遮住输入框
//开始编辑输入框的时候，软键盘出现，执行此事件
-(void)textFieldDidBeginEditing:(UITextField *)textField
{
CGRect frame = textField.frame;
int offset = frame.origin.y +100 - (self.view.frame.size.height - 216.0);//键盘高度216 （100这个根据自己的情况而定）
NSTimeInterval animationDuration = 0.30f;
[UIView beginAnimations:@"ResizeForKeyboard" context:nil];
[UIView setAnimationDuration:animationDuration];
//将视图的Y坐标向上移动offset个单位，以使下面腾出地方用于软键盘的显示
if(offset < 0)
self.view.frame = CGRectMake(0.0f, offset, self.view.frame.size.width, self.view.frame.size.height);
[UIView commitAnimations];
}
//当用户按下return键或者按回车键，keyboard消失
-(BOOL)textFieldShouldReturn:(UITextField *)textField
{
[textField resignFirstResponder];
//判断ios版本
if ([[[UIDevice currentDevice]systemVersion]doubleValue]>=7.0) {
self.view.frame = [UIScreen mainScreen].bounds;
}else{
self.view.frame = [UIScreen mainScreen].applicationFrame;
}
return YES;
}
//结束编辑
-(void)textFieldDidEndEditing:(UITextField *)textField{
//判断ios版本
if ([[[UIDevice currentDevice]systemVersion]doubleValue]>=7.0) {
self.view.frame = [UIScreen mainScreen].bounds;
}else{
self.view.frame = [UIScreen mainScreen].applicationFrame;
}
}
#pragma -mark 隐藏键盘
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{
[txt2 resignFirstResponder];
//判断ios版本
if ([[[UIDevice currentDevice]systemVersion]doubleValue]>=7.0) {
self.view.frame = [UIScreen mainScreen].bounds;
}else{
self.view.frame = [UIScreen mainScreen].applicationFrame;
}
}
七、控制UITextField的字符个数（此例最多140字符）
在ViewDidLoad里或ViewDidAppear里写通知
[[NSNotificationCenter defaultCenter]addObserver:self selector:@selector(textViewEditChanged:)
name:UITextViewTextDidChangeNotification
object:txtDetail];
然后：
-(void)textViewEditChanged:(NSNotification *)obj{
SSTextView *textField = (SSTextView *)obj.object;
[self textViewChange:textField.text];
}
-(void)textViewChange:(NSString *)newText
{
NSString *toBeString = newText;
NSString *lang = [[UITextInputMode currentInputMode] primaryLanguage]; // 键盘输入模式
if ([lang isEqualToString:@"zh-Hans"]) { // 简体中文输入，包括简体拼音，健体五笔，简体手写
UITextRange *selectedRange = [txtDetail markedTextRange];
//获取高亮部分
UITextPosition *position = [txtDetail positionFromPosition:selectedRange.start offset:0];
// 没有高亮选择的字，则对已输入的文字进行字数统计和限制
if (!position) {
if (toBeString.length > 140) {
txtDetail.text = [toBeString substringToIndex:140];
if (nums==1) {
[alert show];
}
nums++;
}
}
// 有高亮选择的字符串，则暂不对文字进行统计和限制
else{
}
}
// 中文输入法以外的直接对其统计限制即可，不考虑其他语种情况
else{
if (toBeString.length > 140) {
txtDetail.text = [toBeString substringToIndex:140];
}
}
}
