IOS開發基礎知識--片段13，ios基礎知識--片段

IOS開發基礎知識--片段13，ios基礎知識--片段

1:運行程式報the file couldn't be opened because you don't have permission to view it 

解決辦法：項目—>targets->build settings->build options->changed the value of the "Compiler for C/C++/Objective-C" to Default Compiler. 

2:百度地圖引用

1.1引用的是.framework形式開發包時，引入的命名空間則是#import <BaiduMapAPI/BMapKit.h>//引入所有的標頭檔#import <BaiduMapAPI/BMKMapView.h>//只引入所需的單個標頭檔如果是引入用的是.a形式開發包時，引入的命名空間則是#import “BMapKit.h"1.2百度地圖現在提供的兩個.framework的包，一個是真機一個是測試機，可以使用終端的命令把它合成一個；

3:自訂圖釘百度地圖

- (void)viewDidLoad {    [super viewDidLoad];        //百度地圖初始化    _mapView=[[BMKMapView alloc] initWithFrame:CGRectMake(0, 0, SCREEN_WIDTH, SCREEN_HEIGHT-NAVBARHEIGHT)];    _mapView.delegate=self;    [self.view addSubview:_mapView];        //標出座標點    [self addPointAnnotation];}//添加標註- (void)addPointAnnotation{    for (int i=0; i<self.coordinates.count; i++) {        coordinateBean *model=self.coordinates[i];                BMKPointAnnotation* pointAnnotation = [[BMKPointAnnotation alloc]init];        CLLocationCoordinate2D coor;        coor.latitude = model.latitude;        coor.longitude = model.longitude;        pointAnnotation.coordinate = coor;                //通過title來起到傳值的作用        pointAnnotation.title=[NSString stringWithFormat:@"%d",i];        [_mapView addAnnotation:pointAnnotation];        //顯示彈出窗        [_mapView selectAnnotation:pointAnnotation animated:YES];                                //判斷那個是中心，沒有則0必傳參數        if (i==self.selectIndex) {            BMKCoordinateRegion region; ////表示範圍的結構體            region.center.latitude  = model.latitude;// 中心中            region.center.longitude = model.longitude;            region.span.latitudeDelta = 0;//經度範圍（設定為0.1表示顯示範圍為0.2的緯度範圍）            region.span.longitudeDelta = 0;//緯度範圍                        [_mapView setRegion:region];        }    }}//處理自訂彈出視圖- (BMKAnnotationView *)mapView:(BMKMapView *)mapView viewForAnnotation:(id <BMKAnnotation>)annotation{    if ([annotation isKindOfClass:[BMKPointAnnotation class]]) {        BMKPinAnnotationView *newAnnotationView = [[BMKPinAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:@"myrenameMark"];        newAnnotationView.pinColor = BMKPinAnnotationColorPurple;        newAnnotationView.animatesDrop = YES;// 設定該標註點動畫顯示               newAnnotationView.image = [UIImage imageNamed:self.mapPointImageName];   //把圖釘換成別的圖片                int selectIndex=[((BMKPointAnnotation *)annotation).title intValue];        //獲得值        coordinateBean *model=[self.coordinates objectAtIndex:[((BMKPointAnnotation *)annotation).title intValue]];                        UIView *popView=[[UIView alloc]initWithFrame:CGRectMake(0, 3, 100, 20)];                UIImage *img=[UIImage imageNamed:@"mapViewBackground"];        UIEdgeInsets edge=UIEdgeInsetsMake(0, 20, 0, 10);        img=[img resizableImageWithCapInsets:edge resizingMode:UIImageResizingModeStretch];        UIImageView *myimage=[[UIImageView alloc] initWithImage:img];        myimage.frame=CGRectMake(30, 0, 100, 40);        myimage.userInteractionEnabled=YES;                [popView addSubview:myimage];                        //自訂顯示的內容        UILabel *driverName = [[UILabel alloc]initWithFrame:CGRectMake(0, 3, 100, 15)];        driverName.backgroundColor=[UIColor clearColor];        driverName.text=model.title;        driverName.font = [UIFont systemFontOfSize:12];        driverName.textColor = [UIColor blackColor];        driverName.textAlignment = NSTextAlignmentLeft;        [myimage addSubview:driverName];                UILabel *carName = [[UILabel alloc]initWithFrame:CGRectMake(0, 18, 100, 15)];        carName.backgroundColor=[UIColor clearColor];        carName.text=model.comments;        carName.font = [UIFont systemFontOfSize:12];        carName.textColor = [UIColor blackColor];        carName.textAlignment = NSTextAlignmentLeft;        [myimage addSubview:carName];                        BMKActionPaopaoView *pView = [[BMKActionPaopaoView alloc]initWithCustomView:popView];        pView.frame = CGRectMake(0, 0, 100, 40);        ((BMKPinAnnotationView*)newAnnotationView).paopaoView = nil;        ((BMKPinAnnotationView*)newAnnotationView).paopaoView = pView;        newAnnotationView.tag=selectIndex+10;                return newAnnotationView;    }    return nil;}- (void)didReceiveMemoryWarning {    [super didReceiveMemoryWarning];    // Dispose of any resources that can be recreated.}/** *  @author wujunyang, 15-05-12 13:05:05 * *  @brief  跟對百度地圖的處理 *  @param animated <#animated description#> */-(void)viewWillAppear:(BOOL)animated{    [_mapView viewWillAppear];    _mapView.delegate=self;    _locationService.delegate=self;}/** *  @author wujunyang, 15-01-06 10:01:53 * *  跟對百度地圖的處理 * *  @param animated <#animated description#> */-(void)viewWillDisappear:(BOOL)animated{    [_mapView viewWillDisappear];    _mapView.delegate=nil;    _locationService.delegate=nil；}其中有個自訂model:@interface coordinateBean : NSObject//緯度@property(assign,nonatomic)float latitude;//經度@property(assign,nonatomic)float longitude;//標題@property(strong,nonatomic)NSString *title;//註解@property(strong,nonatomic)NSString *comments;@end

 4：自動隱藏和顯示工具列和導航條

toolbar屬性、toolbarItems與上一講的navigationBar、navigationItem類似。只不過toolbarItems沒有navigationItem的左右區分，它就自己一個人在做事，相當於沒有下屬。可以在toolbar上設定很多，比如背景顏色、背景圖片、背景樣式、大小位置（不過有些貌似設定無效），當然和navigationBar一樣，對於它的是否顯示和隱藏是由它的老爸即navigationController控制的。所以[self.navigationController setNavigationBarHidden:YES animated:YES];也會把底部的toolBarItems給隱藏起來，如果要隱藏導航又不想底部toolBarItems被隱藏掉，可以用普通的view替代toolBarItems;首先在viewDidLoad裡設定toolBarHidden = NO, 預設是YES（隱藏的）為了讓toolbar顯示，需要設定為NO（不隱藏）。- (void)viewDidLoad{    [super viewDidLoad];    self.title = @"隱藏導覽列";    // self.toolbarItems    self.navigationController.toolbar.barStyle = self.toolBar.barStyle;    self.navigationController.toolbarHidden = NO;    [self.navigationController.toolbar setTranslucent:YES];     self.toolbarItems = [[[NSMutableArray alloc] initWithArray:self.toolBar.items] autorelease];} 在點擊中間button的時候的顯示和隱藏navigation bar和toolBar實現代碼如下：- (IBAction)toggleNavigationBar:(id)sender{    //Check the current state of the navigation bar...    BOOL navBarState = [self.navigationController isNavigationBarHidden];    //Set the navigationBarHidden to the opposite of the current state.    [self.navigationController setNavigationBarHidden:!navBarState animated:YES];    [self.navigationController setToolbarHidden:!navBarState animated:YES];    //Change the label on the button.    if (navBarState)    {        [button setTitle:@"隱藏 Navigationr and toolbar" forState:UIControlStateNormal];        [button setTitle:@"隱藏 Navigation Bar toolbar" forState:UIControlStateHighlighted];    }    else    {        [button setTitle:@"顯示 Navigation Bar toolbar" forState:UIControlStateNormal];        [button setTitle:@"顯示 Navigation Bar toolbar" forState:UIControlStateHighlighted];    }}

5：View代碼結構的一些建議

在viewDidload裡面只做addSubview的事情，然後在viewWillAppear裡面做布局的事情，最後在viewDidAppear裡面做Notification的監聽之類的事情。至於屬性的初始化，則交給getter去做。@interface CustomObject()@property (nonatomic, strong) UILabel *label;@end@implement#pragma mark - life cycle- (void)viewDidLoad{    [super viewDidLoad];    [self.view addSubview:self.label];}- (void)viewWillAppear:(BOOL)animated{    [super viewWillAppear:animated];    self.label.frame = CGRectMake(1, 2, 3, 4);}#pragma mark - getters and setters- (UILabel *)label{    if (_label == nil) {        _label = [[UILabel alloc] init];        _label.text = @"1234";        _label.font = [UIFont systemFontOfSize:12];        ... ...    }    return label;}@end注意：*重點，在get方法裡面不能寫self.noLabel；千萬不要用“點”文法，這樣會造成get方法死迴圈，因為“點”文法就是調用的get方法，所以要用底線屬性名稱的方法得到對象（在記憶體這其實是一個指標）。

6: iOS中的產生隨機數方法

產生0-x之間的隨機正整數int value =arc4random_uniform(x ＋ 1);產生隨機正整數int value = arc4random() 通過arc4random() 擷取0到x-1之間的整數的代碼如下：int value = arc4random() % x; 擷取1到x之間的整數的代碼如下: int value = (arc4random() % x) + 1; 最後如果想產生一個浮點數，可以在項目中定義如下宏：#define ARC4RANDOM_MAX      0x100000000 然後就可以使用arc4random() 來擷取0到100之間浮點數了（精度是rand（）的兩倍），代碼如下：double val = floorf(((double)arc4random() / ARC4RANDOM_MAX) * 100.0f);執行個體(從數組中隨機顯示出一個背景圖,再通過網路載入顯示出來): self.bgView=[[UIImageView alloc] initWithFrame:CGRectMake(0, 0, SCREEN_WIDTH, SCREEN_HEIGHT)];    self.bgView.image=[UIImage imageNamed:@"AppBg"];    [self.view addSubview:self.bgView];    [self.view sendSubviewToBack:self.bgView];        NSDictionary *params=[[NSDictionary alloc] init];    [[HomeMainNetAPIManager sharedManager] getBackgroundImage:params andBlock:^(id data, NSError *error) {        if (!error&&data) {            BackgroundImageBean *groundImagebean =(BackgroundImageBean *)data;            int dataNum=groundImagebean.data.count;            if (groundImagebean.data&&dataNum>0) {                int r=arc4random_uniform(dataNum);                GroundImageBean *curBean=groundImagebean.data[r];                [self.bgView sd_setImageWithURL:[NSURL URLWithString:curBean.ImgUrl] placeholderImage:[UIImage imageNamed:@"AppBg"] completed:^(UIImage *image, NSError *error, SDImageCacheType cacheType, NSURL *imageURL) {                    dispatch_async(dispatch_get_main_queue(), ^{                        self.bgView.image=image;                    });                }];            }        }    }];

7：沙箱路徑知識整理

模擬器的路徑從之前的~/Library/Application Support/iPhone Simulator移動到了~/Library/Developer/CoreSimulator/Devices/檔案都在個人使用者名稱檔案夾下的一個隱藏檔案夾裡，中文叫資產庫，他的目錄其實是Library。因為應用是在沙箱（sandbox）中的，在檔案讀寫權限上受到限制，只能在幾個目錄下讀寫檔案：Documents：應用中使用者資料可以放在這裡，iTunes備份和恢複的時候會包括此目錄tmp：存放臨時檔案，iTunes不會備份和恢複此目錄，此目錄下檔案可能會在應用退出後刪除Library/Caches：存放快取檔案，iTunes不會備份此目錄，此目錄下檔案不會在應用退出刪除iTunes在與iPhone同步時，備份所有的Documents和Library檔案。iPhone在重啟時，會丟棄所有的tmp檔案。查看方法：方法1、可以設定顯示隱藏檔案，然後在Finder下直接開啟。設定查看隱藏檔案的方法如下：開啟終端，輸入命名(1)顯示Mac隱藏檔案的命令：defaults write com.apple.finder AppleShowAllFiles -bool true(2)隱藏Mac隱藏檔案的命令：defaults write com.apple.finder AppleShowAllFiles -bool false(3)輸完單擊Enter鍵，退出終端，重新啟動Finder就可以了 重啟Finder：按一下滑鼠視窗左上方的蘋果標誌-->強制退出-->Finder-->現在能看到資產庫檔案夾了。 開啟資產庫後找到/Application Support/iPhone Simulator/檔案夾。這裡面就是模擬器的各個程式的沙箱目錄了。方法2、這種方法更方便，在Finder上點->前往->前往檔案夾，輸入/Users/username/Library/Application Support/iPhone Simulator/  前往。username這裡寫使用者名稱。 自訂類返回各目錄路徑：#import <Foundation/Foundation.h>@interface ICSandboxHelper : NSObject+ (NSString *)homePath;     // 程式主目錄，可見子目錄(3個):Documents、Library、tmp+ (NSString *)appPath;        // 程式目錄，不能存任何東西+ (NSString *)docPath;        // 文檔目錄，需要ITUNES同步備份的資料存這裡，可存放使用者資料+ (NSString *)libPrefPath;    // 配置目錄，設定檔存這裡+ (NSString *)libCachePath;    // 緩衝目錄，系統永遠不會刪除這裡的檔案，ITUNES會刪除+ (NSString *)tmpPath;        // 臨時緩衝目錄，APP退出後，系統可能會刪除這裡的內容+ (BOOL)hasLive:(NSString *)path; //判斷目錄是否存在，不存在則建立實現代碼:#import "ICSandboxHelper.h"@implementation ICSandboxHelper+ (NSString *)homePath{    return NSHomeDirectory();}+ (NSString *)appPath{    NSArray * paths = NSSearchPathForDirectoriesInDomains(NSApplicationDirectory, NSUserDomainMask, YES);    return [paths objectAtIndex:0];}+ (NSString *)docPath{    NSArray * paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);    return [paths objectAtIndex:0];}+ (NSString *)libPrefPath{    NSArray * paths = NSSearchPathForDirectoriesInDomains(NSLibraryDirectory, NSUserDomainMask, YES);    return [[paths objectAtIndex:0] stringByAppendingFormat:@"/Preference"];}+ (NSString *)libCachePath{    NSArray * paths = NSSearchPathForDirectoriesInDomains(NSLibraryDirectory, NSUserDomainMask, YES);    return [[paths objectAtIndex:0] stringByAppendingFormat:@"/Caches"];}+ (NSString *)tmpPath{return [NSHomeDirectory() stringByAppendingFormat:@"/tmp"];}+ (BOOL)hasLive:(NSString *)path{    if ( NO == [[NSFileManager defaultManager] fileExistsAtPath:path] )    {        return [[NSFileManager defaultManager] createDirectoryAtPath:path                                         withIntermediateDirectories:YES                                                          attributes:nil                                                               error:NULL];    }        return NO;}