处理键盘不能拉起主app的问题

CustomKeyboard/View/KBKeyboardView.m

@@ -264,6 +264,9 @@
     if (firstChar) {
         for (KBKeyButton *b in row.subviews) {
             if (![b isKindOfClass:[KBKeyButton class]]) continue;
+            // 当本行没有字符键时，firstChar 可能是一个“特殊键”，
+            // 避免对基准按钮自身添加 self == self * k 的无效约束
+            if (b == firstChar) continue;
             if (b.key.type == KBKeyTypeCharacter) continue;
             CGFloat multiplier = 1.5;
             if (b.key.type == KBKeyTypeSpace) multiplier = 4.0;