iOS 開發教學 - Google Map API 之使用 MapKit framework

在 iPhone 的應用程式中，有許多熱門是使用 Google Map 的服務，透過 mobile device 的行動性，使得科技服務與生活有更密切的結合。在此使用 iPhone SDK 3.0 的 Mapkit framework 實作。

相關資料如下：

• Maps - Get Ready for iPhone OS 3.0 - iPhone Developer Program


• iPhone Dev Center: MapKit Framework Reference


• iPhone SDK 3.0 – Playing with Map Kit

建立一個新的 Project ，[Xcode]->[Create a New Xcode Project]->[iPhone
OS]->[Application]->[Window-based Application] 取名為 MyMap 。並且對左邊介面上之目錄列表裡的 Framework ，按他一下並點選右鍵來加入 MapKit Framework

[Framework] -> [Add] -> [Existing Frameworks] ->[MapKit.framework]

MyMapAppDelegate.h

#import <UIKit/UIKit.h>
#import <MapKit/MapKit.h>

@interface MyMapAppDelegate : NSObject <UIApplicationDelegate> {
    UIWindow *window;
    MKMapView *myMap;    
}

@property (nonatomic, retain) IBOutlet UIWindow *window;

@end

MyMapAppDelegate.m

#import "MyMapAppDelegate.h"

@implementation MyMapAppDelegate

@synthesize window;

- (void)applicationDidFinishLaunching:(UIApplication *)application {
    CGRect full = CGRectMake(0, 0, 320, 460);
    myMap = [[MKMapView alloc] initWithFrame:full];
    [window addSubview:myMap];
    // Override point for customization after application launch
    [window makeKeyAndVisible];
}

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

@end

成果

以上是一個精簡的範例，但並不實用，而程式碼的重複使用也不佳，更好的使用方式是在為這個範例增加一個 ViewController：

[Xcode]->[File]->[New File]->[Cocoa Touch Class]->[UIViewController subclass] ，在此稱作 GoogleMapView 好了！別忘了勾選 With XIB for user interface

同時修改原先的程式碼：

MyMapAppDelegate.h

#import <UIKit/UIKit.h>
#import "GoogleMapView.h"

@interface MyMapAppDelegate : NSObject <UIApplicationDelegate> {
    UIWindow *window;
    GoogleMapView *gMap;
}

@property (nonatomic, retain) IBOutlet UIWindow *window;

@end

MyMapAppDelegate.m

#import "MyMapAppDelegate.h"

@implementation MyMapAppDelegate

@synthesize window;

- (void)applicationDidFinishLaunching:(UIApplication *)application {
    gMap = [[GoogleMapView alloc] init];
    [window addSubview:gMap.view];
    // Override point for customization after application launch
    [window makeKeyAndVisible];
}

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

@end

新增的程式碼：

GoogleMapView.h

#import <UIKit/UIKit.h>
#import <MapKit/MapKit.h>

@interface GoogleMapView : UIViewController {
    IBOutlet MKMapView *myMap;
}

@end

GoogleMapView.m

#import "GoogleMapView.h"

@implementation GoogleMapView

/*
 // The designated initializer.  Override if you create the controller programmatically and want to perform customization that is not appropriate for viewDidLoad.
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil {
    if (self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil]) {
        // Custom initialization
    }
    return self;
}
*/

// Implement viewDidLoad to do additional setup after loading the view, typically from a nib.
- (void)viewDidLoad {
    [super viewDidLoad];
    myMap = [[MKMapView alloc] initWithFrame:self.view.bounds];
    [self.view addSubview:myMap];
}

// Override to allow orientations other than the default portrait orientation.
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation {
    // Return YES for supported orientations
    return YES;
}

- (void)didReceiveMemoryWarning {
    // Releases the view if it doesn't have a superview.
    [super didReceiveMemoryWarning];
  
    // Release any cached data, images, etc that aren't in use.
}

- (void)viewDidUnload {
    // Release any retained subviews of the main view.
    // e.g. self.myOutlet = nil;
}

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

@end

點擊 GoogleMapView.xib

接下來要設置當 iPhone 轉 90 度依舊能夠填滿整個螢幕，這部份要在 Interface Builder 調整，在 Library 頁面上，找尋 MKMapView 物件並拖拉到 View 的上（可以透過 Library  下方的搜尋），接著也別忘了要按 ctrl 並點選 File's owner 去跟 MKMapView 物件建立 myMap 連線，最後在 Map View Size 那邊可以去調整 Autosizing，把框框四處都點起來，讓他充滿。

如果不設定的話，那到時候的結果會是這樣：

成果：

以上只是簡單的呈現 Google Map ，而弄成一個 UIViewController，是方便以後替它增加一些功能以及提供程式的重複使用性，剩下的有空在補上。