IOS trivia point (continuous update)

1. How to set the font size of button title by code

Set Button.titleLabel.font = [Uifont systemfontofsize:<# (CGFloat) #>];

2. Get the current time

    NSDate *timedate=[nsdate Date];         * Dateformatter=[[NSDateFormatter alloc] init];        [Dateformatter Setdateformat: @" yyyymmddhhmmsssss " ];         *locationstring=[dateformatter Stringfromdate:timedate];

3. The method of judging whether the string is a null character

-(BOOL) isblankstring: (NSString *)string {    if(string= = Nil | |string==NULL) {        returnYES; }    if([stringIskindofclass:[nsnullclass]]) {        returnYES; }    if([[stringStringbytrimmingcharactersinset:[nscharacterset Whitespacecharacterset]] length]==0) {        returnYES; }    returnNO;}

4, TableView optimization

    // Refresh the entire table     [_tableview reloaddata];         // refreshes the current row    [_tableview Reloadrowsatindexpaths:@[indexpath] withrowanimation:uitableviewrowanimationautomatic];

5, Baidu map Custom pin image

-(Bmkannotationview *) Mapview: (Bmkmapview *) View viewforannotation: (ID<BMKAnnotation>) annotation{//generate reuse Flag identifier    StaticNSString *annotationviewid =@"Annotationviewid"; //Check if there is a reuse cachebmkannotationview* Annotationview =[view Dequeuereusableannotationviewwithidentifier:annotationviewid]; ((Bmkpinannotationview*) annotationview). Pincolor =Bmkpinannotationcolorgreen; Annotationview.image= [UIImage imagenamed:@"Xxx.png"];}

IOS trivia point (continuous update)