Implementation of the iOS bullet screen

<span id="Label3"></p><p><p>Simple bullet screen to achieve a bad place to write please advise us</p></p><p><p>In the project settings to set the horizontal screen;</p></p><p><p>Implementation Principle: with the timer to constantly produce lable, the position of the lable produced in the right side of the screen we can not see, we are writing a mobile method to make the lable move to the leftmost place, and then remove the lable, so that the realization of a simple barrage;</p></p><p><p></p></p><p><p>About Timer Nstimer</p></p><p><p>Create</p></p><p><p>nstimer* MyTimer = [nstimer scheduledtimerwithtimeinterval:<# (nstimeinterval) #> target:<# (id) #> Selector : <# (SEL) #> userinfo:<# (id) #> repeats:<# (BOOL) #>];</p></p><p><p>Timeinterval: wait 1 seconds before executing, as set 1</p></p><p><p>Target: the object being sent</p></p><p><p>Selector: the method of execution in this case we are going to execute the method of randomly creating lable;</p></p><p><p>Userinfo: This parameter can be nil;</p></p><p><p>Repeats: whether the loop, when yes, loops to actual effect or release must be added at this time</p></p><p><p>[[nsrunloop mainrunloop] Addtimer:mytimer formode:nsdefaultrunloopmode];</p></p><p><p>When no is only run once will automatically add the timer to the Mainrunloop Nsdefaultrunloopmode in the use of the notice when the notification can be used;</p></p><p><p></p></p><p><p>Code:</p></p><p><p>#import "MainViewController.h"</p></p><p><p>#import the classification of "uicolor+random.h"//uicolor produce random colors</p></p><p><p>@interface Mainviewcontroller ()</p></p><p><p>{</p></p><p><p>nstimer* mytimer;</p></p><p><p>nsmutablearray* arrays; Store the string to eject</p></p><p><p>uibutton* start; Start button</p></p><p><p>uibutton* close; Close button</p></p><p><p>}</p></p><p><p>@end</p></p><p><p></p></p><p><p>@implementation Mainviewcontroller</p></p><p><p>-(void) Viewdidload</p></p><p><p>{</p></p><p><p>[super viewdidload];</p></p><p><p>arrays = [[nsmutablearray alloc]initwithcapacity:10];</p></p><p><p>Below is a plist file I find from other small code, from which I read the data to do the barrage you can simply build an array to add some strings;</p></p><p><p>nsstring* Path = [[nsbundle mainbundle] pathforresource:@ "dishdata" oftype:@ "plist"];</p></p><p><p>nsarray* array = [[nsarray alloc]initwithcontentsoffile:path];</p></p><p><p>For (nsdictionary* arr in Array) {</p></p><p><p>nsstring* name = [arr objectforkey:@ "name"];</p></p><p><p>nsnumber* Price = [arr objectforkey:@ ' Price '];</p></p><p><p>nsstring* str = [nsstring stringwithformat:@ "%@", price];</p></p><p><p>nsstring* Description = [arr objectforkey:@ "description"];</p></p><p><p>[arrays addobject:name];</p></p><p><p>[arrays addobject:str];</p></p><p><p>[arrays addobject:description]</p></p><p><p>}</p></p><p><p>Some settings for the button</p></p><p><p>Start = [[UIButton alloc] initwithframe:cgrectmake (10, 0, 100, 50)];</p></p><p><p>[start addtarget:self action: @selector (start:) forcontrolevents:uicontroleventtouchupinside];</p></p><p><p>[start settitle:@ "open" forstate:uicontrolstatenormal];</p></p><p><p>[start Setbackgroundcolor:[uicolor greencolor]];</p></p><p><p>[self.view addsubview:start];</p></p><p><p>Close = [[UIButton alloc] initwithframe:cgrectmake (10, 0, 100, 50)];</p></p><p><p>[close addtarget:self action: @selector (endtimer:) forcontrolevents:uicontroleventtouchupinside];</p></p><p><p>[close settitle:@ "off" forstate:uicontrolstatenormal];</p></p><p><p>[close Setbackgroundcolor:[uicolor greencolor];</p></p><p><p>Close.hidden = YES;</p></p><p><p>[self.view addsubview:close];</p></p><p><p>}</p></p><p><p>-(void) start: (id) sender{</p></p><p><p>If (mytimer) {</p></p><p><p>Turn on timer</p></p><p><p>[mytimer setfiredate:[nsdate distantpast];</p></p><p><p>}else{</p></p><p><p>MyTimer = [nstimer scheduledtimerwithtimeinterval:0.5 target:self selector: @selector (initlable:) Userinfo:nil Repeats : YES];</p></p><p><p>}</p></p><p><p>And the Implement button in the Close button hides and reproduces</p></p><p><p>Start.hidden = YES;</p></p><p><p>Close.hidden = NO;</p></p><p><p>}</p></p><p><p>Close Button Implementation method</p></p><p><p><span style="line-height: 1.5;">-(void) endtimer: (id) sender{</span></p></p><p><p>Turn off the timer</p></p><p><p>[mytimer setfiredate:[nsdate distantfuture];</p></p><p><p>Cancel Timer Delete Timer This is the only way to go here.</p></p><p><p>[mytimer invalidate];</p></p><p><p>Close.hidden = YES;</p></p><p><p>Start.hidden = NO;</p></p><p><p>}</p></p><p><p>Create lable</p></p><p><p>-(void) initlable: (id) sender{</p></p><p><p>lable display on the right side of the screen is not displayed on the screen</p></p><p><p>uilabel* lable = [[UILabel alloc] initwithframe:cgrectmake (self.view.frame.size.height, rand ()%30*10, 100, 20)];</p></p><p><p>Randomcolor is a class method that I implemented using Classification.</p></p><p><p>[lable Settextcolor:[uicolor randomcolor];</p></p><p><p>[lable settext:[arrays Objectatindex:rand ()%[arrays count]];</p></p><p><p>[self.view addsubview:lable];</p></p><p><p>[self move:lable];</p></p><p><p>}</p></p><p><p>Move the lable to the left of the screen</p></p><p><p>-(void) move: (uilabel*) lable{</p></p><p><p>[UIView Animatewithduration:2 animations:^{</p></p><p><p>Lable.frame = CGRectMake (0-lable.frame.size.width, lable.frame.origin.y, lable.frame.size.width, lable.frame.size.height);</p></p><p><p>}completion:^ (BOOL Finished) {</p></p><p><p>[lable removefromsuperview];</p></p><p><p>}];</p></p><p><p>}</p></p><p><p>Uicolor classification for generating random colors</p></p><p><p>Method of creating classification: new Objective-c category; Category on uicolor;</p></p><p><p>#import <UIKit/UIKit.h></p></p><p><p>@interface Uicolor (Random)</p></p><p><p>Generate Random Colors</p></p><p><p>+ (uicolor*) randomcolor;</p></p><p><p>@end</p></p><p><p>#import "uicolor+random.h"</p></p><p><p>@implementation Uicolor (Random)</p></p><p><p>+ (uicolor*) randomcolor{</p></p><p><p>static BOOL seed = NO;</p></p><p><p>If (!seed) {</p></p><p><p>Seed = YES;</p></p><p><p>Srandom (time (NULL));</p></p><p><p>}</p></p><p><p>Three primary colors can be mixed out all the colors, and added to the white</p></p><p><p>CGFloat red = (cgfloat) random ()/(cgfloat) rand_max;</p></p><p><p>CGFloat green = (cgfloat) random ()/(cgfloat) rand_max;</p></p><p><p>CGFloat blue = (cgfloat) random ()/(cgfloat) rand_max;</p></p><p><p>return [uicolor colorwithred:red green:green blue:blue Alpha:1.0f];//alpha for transparency 0 fully transparent 1 opaque</p></p><p><p></p></p><p><p>}</p></p><p><p>@end</p></p><p><p></p></p><p><p>Implementation of the iOS bullet screen</p></p></span>