防止 多次调用 review by daiqiang

@@ -116,15 +116,21 @@ static NSArray *kYHEventReportIgnoredViewControllerArray;
     [UIAlertView startTrack];
     [UITabBar startTrack];
     
-    NSError *error = NULL;
-    // Actions & Events
-    [UIApplication yh_swizzleMethod:@selector(sendAction:to:from:forEvent:)
-                         withMethod:@selector(yh_sendAction:to:from:forEvent:)
-                              error:&error];
-    if (error) {
-        YHLog(@"Failed to swizzle sendAction:to:forEvent: on UIAppplication. Details: %@", error);
-        error = NULL;
-    }
+    static dispatch_once_t onceToken;
+    dispatch_once(&onceToken, ^{
+        @try {
+            NSError *error = NULL;
+            [UIApplication yh_swizzleMethod:@selector(sendAction:to:from:forEvent:)
+                                 withMethod:@selector(yh_sendAction:to:from:forEvent:)
+                                      error:&error];
+            if (error) {
+                YHLog(@"Failed to swizzle sendAction:to:forEvent: on UIAppplication. Details: %@", error);
+                error = NULL;
+            }
+        } @catch (NSException *exception) {
+            YHLog(@"%@ error: %@", self, exception);
+        }
+    });
 }