在钥匙串中存储app是否是首次启动。Review by 阿达。

@@ -63,5 +63,7 @@
 + (void) setOptOut:(BOOL)optOutValue;
 + (void) setUsedDevice;
 + (BOOL) isNewDevice;
++ (void) setFirstLaunch;
++ (BOOL) isFirstLaunch;
 
 @end

@@ -72,6 +72,7 @@ static NSString * const kYohoBuyUdid = @"com.yoho.buy.udid";
 static BOOL isNew = YES;
 static NSString * const kYohoDeviceInfo = @"com.yoho.buy.deviceinfo";
 static NSString * const kYohoBuyUsedDevice = @"com.yoho.buy.useddevice";
+static NSString * const kYohoBuyFirstLaunch = @"com.yoho.buy.firstlaunch";
 
 @interface OpenUDID (Private)
 + (void) _setDict:(id)dict forPasteboard:(id)pboard;
@@ -419,4 +420,21 @@ static NSString * const kYohoBuyUsedDevice = @"com.yoho.buy.useddevice";
     return isNew;
 }
 
++ (void) setFirstLaunch
+{
+    NSMutableDictionary *yohoinfoKVPairs = [NSMutableDictionary dictionary];
+    [yohoinfoKVPairs setObject:@"N" forKey:kYohoBuyFirstLaunch];
+    [YH_KeychainStore save:kYohoDeviceInfo data:yohoinfoKVPairs];
+}
+
++ (BOOL) isFirstLaunch
+{
+    NSMutableDictionary *yohoinfoKVPairs = (NSMutableDictionary *)[YH_KeychainStore load:kYohoDeviceInfo];
+    if (yohoinfoKVPairs && yohoinfoKVPairs[kYohoBuyFirstLaunch]) {
+        return NO;
+    } else {
+        return YES;
+    }
+}
+
 @end