ios6應用內直接跳轉App Store，不必切換至App Store應用

SKStoreProductViewController類是UIViewController的子類, 如果你對view controller比較熟悉的話，那SKStoreProductViewController使用起來也非常簡單了。當你希望向使用者展示App Store中產品時，你需要：

1.執行個體化一個SKStoreProductViewController類

2.設定它的delegate

3.把sotre product視圖控制器顯示給消費者

剩下的就交給作業系統來處理了。需要記住一點的是SKStoreProductViewController只能以模態的方式顯示。SKStoreProductViewControllerDelegate協議定義了一個單獨的方法—productViewControllerDidFinish:，當消費者離開App Store時會調用這個方法—一般是通過點擊左上方畫面中的取消按鈕。通過給代理髮送productViewControllerDidFinish:訊息，作業系統就會把控制權返回到你的程式。當然你不能忘了 只支援IOS6.0及其以上

.h

#import <Foundation/Foundation.h>@interface InlineAppstore : NSObject+ (InlineAppstore*)sharedInstance;- (void)showAppInApp:(NSString *)_appId;@end

.m

#import "InlineAppstore.h"#import "AppDelegate.h"#import <StoreKit/StoreKit.h>@interface InlineAppstore () <SKStoreProductViewControllerDelegate>@end@implementation InlineAppstore+ (InlineAppstore*)sharedInstance {    static InlineAppstore* pInlineAppstore = nil;        @synchronized(self) {        if (pInlineAppstore == nil) {            pInlineAppstore = [[self alloc] init];        }    }    return pInlineAppstore;}- (void)showAppInApp:(NSString *)_appId {    Class storeVC = NSClassFromString(@"SKStoreProductViewController");    if (storeVC != nil) {        SKStoreProductViewController *_SKSVC = [[SKStoreProductViewController alloc] init];        _SKSVC.delegate = self;        [_SKSVC loadProductWithParameters:@{SKStoreProductParameterITunesItemIdentifier: _appId}                          completionBlock:^(BOOL result, NSError *error) {                              if (result) {                                  [[AppDelegate getInstance].navController presentViewController:_SKSVC                                                                                        animated:YES                                                                                      completion:nil];                              }                              else{                                  NSLog(@"%@",error);                              }                          }];    }    else{        //低於iOS6沒有這個類        NSString *_idStr = [NSString stringWithFormat:@"itms-apps://itunes.apple.com/us/app/id%@?mt=8",_appId];        [[UIApplication sharedApplication] openURL:[NSURL URLWithString:_idStr]];    }}#pragma mark - SKStoreProductViewControllerDelegate- (void)productViewControllerDidFinish:(SKStoreProductViewController *)viewController {    [viewController dismissViewControllerAnimated:YES completion:nil];}