I have a recursive function which can be written like: void func(TypeName *dataStructure, LL_Node **accumulator) { func(datastructure->left, accumulator); func(datastructure->right, accumulator); { char buffer[1000]; // do some stuff } return; } I know that in reality the buffer is being allocated at the beginning of the function and putting t
我有一个递归函数，可以这样写： void func(TypeName *dataStructure, LL_Node **accumulator) { func(datastructure->left, accumulator); func(datastructure->right, accumulator); { char buffer[1000]; // do some stuff } return; } 我知道，实际上缓冲区正在函数的开始处分配，并且将语句放在嵌套的作用域块中实际上并不使用新的堆栈帧。 但我不希望编译器一次分
Like we do with macros: #undef SOMEMACRO Can we also undeclare or delete the variables in C, so that we can save a lot of memory? I know about malloc() and free() , but I want to delete the variables completely so that if I use printf("%d", a); I should get error test.c:4:14: error: ‘a’ undeclared (first use in this function) No, but you can create small minimum scopes to achiev
就像我们使用宏一样： #undef SOMEMACRO 我们是否也可以取消声明或删除C中的变量，以便我们可以节省大量内存？ 我知道malloc()和free() ，但我想完全删除这些变量，这样如果我使用printf("%d", a); 我应该得到错误 test.c:4:14: error: ‘a’ undeclared (first use in this function) 不，但是您可以创建小型的最小范围来实现这一点，因为当范围退出时，所有范围局部变量都会被销毁。 像这样的东西： void foo
What I have is simple switch statement Control myControl; switch(x) { case TabType.Edit: { myControl= ...; } case TabType.View: { myControl= ...; } } myPageView.Controls.Add(myControl); In this situation compiler tells me that local variable myControl might not be initialized before accessing So, what is the best way to avoid this situati
我拥有的是简单的switch语句 Control myControl; switch(x) { case TabType.Edit: { myControl= ...; } case TabType.View: { myControl= ...; } } myPageView.Controls.Add(myControl); 在这种情况下，编译器告诉我 局部变量myControl在访问之前可能未被初始化 那么，避免这种情况的最好方法是什么？ 一种选择是在switch语句之前初始化myControl。 但在这种情况
How are statements that come before any case labelled statement in a switch-case block treated. Please explain the behavior of the following programs prog1: #include<stdio.h> int main() { switch(1) { int i=0; case 1:printf("%d",i); } getchar(); return 0; } Output: garbage value. prog2: #include<stdio.h> int main() { switch(1) { printf("Insi
如何处理switch-case块中的任何case标记语句之前的语句。 请解释以下程序的行为 PROG1： #include<stdio.h> int main() { switch(1) { int i=0; case 1:printf("%d",i); } getchar(); return 0; } 输出：垃圾值。 PROG2： #include<stdio.h> int main() { switch(1) { printf("Inside Switch"); case 1:printf("Case 1n"); } printf("Outside Switch")
Background In PHP there is a shorthand for the ternary operator: $value = ""; echo $value ?: "value was empty"; // same as $value == "" ? "value was empty" : $value; In JS there's also an equivalent: var value = ""; var ret = value || "value was empty"; // same as var ret = value == "" ? "value was empty" : value; But in C#, there's (as far as i know) only the "full" versi
背景 在PHP中有三元运算符的简写： $value = ""; echo $value ?: "value was empty"; // same as $value == "" ? "value was empty" : $value; 在JS中也有一个等价的： var value = ""; var ret = value || "value was empty"; // same as var ret = value == "" ? "value was empty" : value; 但在C＃中，有（只要我知道）只有“完整”版本的作品： string Value = ""; string Result = Value == string.Empty ? "value was
Deserializing of Expression tree using ExpressionSerialization on a full conditional expression ie ternary operator is giving error . If i am using ternary operator it causes FullConditionExpression (System Not Supported Exception) Using code from following links: http://archive.msdn.microsoft.com/exprserialization Are there any latest version available for the above link? http://metalin
在完整的条件表达式上使用ExpressionSerialization反序列化表达式树，即三元运算符会给出错误。 如果我使用三元运算符，它会导致FullConditionExpression（系统不支持异常） 使用以下链接中的代码： http://archive.msdn.microsoft.com/exprserialization 有没有可用于上述链接的最新版本？ http://metalinq.codeplex.com/ 之后尝试过 public Expression<Func<object, string>> LabelCriteria { get; set
看到C＃无法切换类型（我收集的类型并未作为特例添加，因为是 - 关系表示可能会应用多个不同的情况 ），有没有更好的方法来模拟类型切换？ void Foo(object o) { if (o is A) { ((A)o).Hop(); } else if (o is B) { ((B)o).Skip(); } else { throw new ArgumentException("Unexpected type: " + o.GetType()); } } Switching on types is definitely lacking in C#
看到C＃无法切换类型（我收集的类型并未作为特例添加，因为是 - 关系表示可能会应用多个不同的情况 ），有没有更好的方法来模拟类型切换？ void Foo(object o) { if (o is A) { ((A)o).Hop(); } else if (o is B) { ((B)o).Skip(); } else { throw new ArgumentException("Unexpected type: " + o.GetType()); } } 在C＃中切换类型肯定是缺乏的（更新：在C＃7 / VS
I have 96 txt files that have to be processed. Right now I am using a for loop and doing them one at a time, this process is very slow. The resulting 96 files, do not need to be merged. Is there a way to make them run in parallel, ala Parallel.foreach in C#? Current code: for src_name in glob.glob(source_dir+'/*.txt'): outfile = open (...) with open(...) as infile: for line in in
我有96个txt文件需要处理。 现在我正在使用for循环并一次只做一个，这个过程非常缓慢。 生成的96个文件不需要合并。 有没有办法让它们平行运行，ala Parallel.foreach在C＃中？ 当前代码： for src_name in glob.glob(source_dir+'/*.txt'): outfile = open (...) with open(...) as infile: for line in infile: --PROCESS-- for --condition--: outfile.write(...) infile.close() ou
I'd like to reinterpret a string in a array of int where every int take charge of 4 or 8 chars based on processor architecture. Is there a way to achieve this in a relatively inexpensive way? I tried out this but doesn't seem to reinterpret 4 chars in one int string text = "abcdabcdefghefgh"; unsafe { fixed( char* charPointer = text ) { Int32* intPointer = (Int32*)cha
我想重新解释一个int数组中的字符串，其中每个int根据处理器体系结构负责4或8个字符。 有没有办法以相对廉价的方式实现这一点？ 我试过这个，但似乎没有重新解释一个int中的4个字符 string text = "abcdabcdefghefgh"; unsafe { fixed( char* charPointer = text ) { Int32* intPointer = (Int32*)charPointer; for( int index = 0; index < text.Length / 4; index++ ) {
I have an app that I need to compress RGB bitmap data into to byte array with JPEG format. So I use the Image.Save(Stream stream, ImageFormat foramt) to save into a MemoryStream and then convert to byte[] using(MemoryStream ms = new MemoryStream()) using(Bitmap bmp = new Bitmap(640, 480, PixelFormat.Format24bppRgb)) { bmp.Save(ms, SaveFormat); } The code is fine with .NetFramework 4.0 on W
我有一个应用程序，我需要将RGB位图数据压缩为JPEG格式的字节数组。 所以我使用Image.Save(Stream stream, ImageFormat foramt)保存到MemoryStream ，然后转换为byte[] using(MemoryStream ms = new MemoryStream()) using(Bitmap bmp = new Bitmap(640, 480, PixelFormat.Format24bppRgb)) { bmp.Save(ms, SaveFormat); } 在Windows 7上使用.NetFramework 4.0时代码很好，但是当我在Ubuntu上运行与单声道运行时相同的程