speed up

speed up

MJRefresh/UIScrollView+MJExtension.m

@@ -10,17 +10,22 @@
 #import "UIScrollView+MJExtension.h"
 #import <objc/runtime.h>
 
-#define SYSTEM_VERSION_GREATER_NOT_LESS_THAN(v)  ([[[UIDevice currentDevice] systemVersion] compare:v options:NSNumericSearch] != NSOrderedAscending)
-
 #pragma clang diagnostic push
 #pragma clang diagnostic ignored "-Wunguarded-availability-new"
 
 @implementation UIScrollView (MJExtension)
 
+static BOOL gt_ios_11_;
++ (void)load
+{
+    // 缓存判断值
+    gt_ios_11_ = [[[UIDevice currentDevice] systemVersion] compare:@"11.0" options:NSNumericSearch] != NSOrderedAscending;
+}
+
 - (UIEdgeInsets)mj_inset
 {
 #ifdef __IPHONE_11_0
-    if (SYSTEM_VERSION_GREATER_NOT_LESS_THAN(@"11.0")) {
+    if (gt_ios_11_) {
         return self.adjustedContentInset;
     }
 #endif
@@ -32,7 +37,7 @@ - (void)setMj_insetT:(CGFloat)mj_insetT
     UIEdgeInsets inset = self.contentInset;
     inset.top = mj_insetT;
 #ifdef __IPHONE_11_0
-    if (SYSTEM_VERSION_GREATER_NOT_LESS_THAN(@"11.0")) {
+    if (gt_ios_11_) {
         inset.top -= (self.adjustedContentInset.top - self.contentInset.top);
     }
 #endif
@@ -49,7 +54,7 @@ - (void)setMj_insetB:(CGFloat)mj_insetB
     UIEdgeInsets inset = self.contentInset;
     inset.bottom = mj_insetB;
 #ifdef __IPHONE_11_0
-    if (SYSTEM_VERSION_GREATER_NOT_LESS_THAN(@"11.0")) {
+    if (gt_ios_11_) {
         inset.bottom -= (self.adjustedContentInset.bottom - self.contentInset.bottom);
     }
 #endif
@@ -66,7 +71,7 @@ - (void)setMj_insetL:(CGFloat)mj_insetL
     UIEdgeInsets inset = self.contentInset;
     inset.left = mj_insetL;
 #ifdef __IPHONE_11_0
-    if (SYSTEM_VERSION_GREATER_NOT_LESS_THAN(@"11.0")) {
+    if (gt_ios_11_) {
         inset.left -= (self.adjustedContentInset.left - self.contentInset.left);
     }
 #endif
@@ -83,7 +88,7 @@ - (void)setMj_insetR:(CGFloat)mj_insetR
     UIEdgeInsets inset = self.contentInset;
     inset.right = mj_insetR;
 #ifdef __IPHONE_11_0
-    if (SYSTEM_VERSION_GREATER_NOT_LESS_THAN(@"11.0")) {
+    if (gt_ios_11_) {
         inset.right -= (self.adjustedContentInset.right - self.contentInset.right);
     }
 #endif