itemView使用约束来控制

GMBase/Classes/OCNavigationBar.m

@@ -44,8 +44,7 @@
         make.right.mas_equalTo(0);
         make.height.offset(1/[UIScreen mainScreen].scale);
     }];
-    _itemView = [[UIView alloc] initWithFrame:CGRectMake(0, [UIApplication sharedApplication].statusBarFrame.size.height, [UIScreen mainScreen].bounds.size.width, 44)];
-    _itemView.autoresizingMask = UIViewAutoresizingFlexibleWidth;
+    _itemView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, [UIScreen mainScreen].bounds.size.width, 44)];
     CGFloat titleW = [UIScreen mainScreen].bounds.size.width - 80;
     _titleLabel = [[UILabel alloc] initWithFrame:CGRectMake(40, 0, titleW, 44)];
     _titleLabel.lineBreakMode = NSLineBreakByTruncatingTail;
@@ -74,6 +73,10 @@
     [_itemView addSubview:_leftButton];
     [_itemView addSubview:_rightButton];
     [_itemView addSubview:_nearRightButton];
+    [_itemView mas_makeConstraints:^(MASConstraintMaker *make) {
+        make.left.right.bottom.mas_equalTo(0);
+        make.height.mas_equalTo(44);
+    }];
     [_leftButton mas_makeConstraints:^(MASConstraintMaker *make) {
         make.left.mas_equalTo(20);
         make.centerY.mas_equalTo(0);