I have a printf statement as follows: printf("[%d] %d", i, n->data); I'm trying to make the related code flexible so you can change the variable type of "n->data" depending on your need. Is there a way to make the format specifier update depending on the variable type used? I've tried including: const char FS[2] = "%f"; when the variable is a float, then amending th
我有一个printf语句如下： printf("[%d] %d", i, n->data); 我试图使相关代码更加灵活，以便根据需要更改“n-> data”的变量类型。 有没有办法让格式说明符更新取决于使用的变量类型？ 我试过包括： const char FS[2] = "%f"; 当变量是一个float时，然后修改printf语句来： printf("[%d] "FS, i, n->data); 但是这会得到以下错误，我不知道如何解决： dLList.c:125:23: error: expected ')' printf("[%d
I have a program with two variables of type int. int num; int other_num; /* change the values of num and other_num with conditional increments */ printf ("result = %fn", (float) num / other_num); float r = (float) num / other_num; printf ("result = %fn", r); The value written in the first printf is different from the value written by the second printf (by 0.000001, when printed with 6 decima
我有一个程序有两个int类型的变量。 int num; int other_num; /* change the values of num and other_num with conditional increments */ printf ("result = %fn", (float) num / other_num); float r = (float) num / other_num; printf ("result = %fn", r); 在第一个printf中写入的值与由第二个printf写入的值不同（当以小数点后6位打印时，为0.000001）。 在划分之前，这些值是： num = 10201 other_num = 2282
I'm using Visual Studio TC compiler for Little Endian. The following is the piece of code: void main() { float c = 1.0; int a = 0x3F800000; int *ptr = (int *)&c; printf("n0x%Xn", *ptr); printf("na = %f", a); printf("nc = %f", c); return; } The output is: 0x3F800000 a = 0.000000 c = 1.000000 Float value 1.0 is 0x3F800000 and stored as 00 00 80 3F in
我为Little Endian使用Visual Studio TC编译器。 以下是这段代码： void main() { float c = 1.0; int a = 0x3F800000; int *ptr = (int *)&c; printf("n0x%Xn", *ptr); printf("na = %f", a); printf("nc = %f", c); return; } 输出是： 0x3F800000 a = 0.000000 c = 1.000000 浮点值1.0是0x3F800000，并且在Little Endian的存储器中存储为00 00 80 3F。 相同的值被分配给int a
I'm trying to solve exercise 2-1 from "The C Programming Language", 2nd edition, which asks to: "Write a program to determine the ranges of char, short, int, and long variables, both signed and unsigned, by printing appropriate values from standard headers and by direct computation. Harder if you compute them: determine the ranges of the various floating-point types."
我试图从“The C Programming Language”第二版中解决练习2-1，它要求： “编写一个程序，通过从标准头文件和直接计算中打印适当的值来确定char，short，int和long变量（有符号和无符号）的范围，如果计算它们，则更难：确定各种浮点数的范围，点类型“。 我已经设法确定除了浮点之外的所有类型的范围，都使用标准头文件中的最小值和最大值以及直接计算。 如何使用直接计算确定浮点类型的范围？ #include <stdio.h> #inc
As I want to keep track of some variables in order to see how they change, I want to create a function, which receives a format string, depending on the variable's type and a pointer to the value. I hope, that with the help of the format string, printf will properly determine the value. Actually it works, but with one exception - the float values do not print properly. This is my code: #
由于我想跟踪一些变量以查看它们如何变化，我想创建一个函数，该函数接收格式字符串，具体取决于变量的类型和指向该值的指针。 我希望，在格式字符串的帮助下，printf将正确地确定值。 实际上它有效，但有一个例外 - 浮点值不能正确打印。 这是我的代码： #include <stdio.h> void pprint (char* fmtstr, void* p) { printf(fmtstr,*(long double *)p); } int main (int argc, char **argv) { char
I am getting this error: System.Data.Entity.Validation.DbEntityValidationException: Validation failed for one or more entities. See 'EntityValidationErrors' property for more details. In visual studio. There are several posts on here about it however all of them seem to be running a "seed" method somewhere in the application flow. In my case I am trying to seed the datab
我得到这个错误： System.Data.Entity.Validation.DbEntityValidationException：一个或多个实体的验证失败。 有关更多详细信息，请参阅“EntityValidationErrors”属性。 在视觉工作室。 这里有几篇关于它的文章，但它们似乎都在应用程序流程中的某处运行“种子”方法。 在我的情况下，我试图在迁移的配置中对数据库进行种子处理。 如果这是不适当的，请让我知道。 现在有办法在运行Update-Database时以任何方式捕获异常
I have a solution with 2 projects in it, an asp.net core mvc 1.0.1 and a .NET 4.6.1 class library with EF6 which contains my entities, domain models, abstractions and viewmodels. I have added the class library as a reference in my asp.net core project. I set my class library project as my startup project and enable migrations and even add successfully. But once I do Update-Database, I get an e
我有一个包含2个项目的解决方案，一个asp.net核心mvc 1.0.1和一个带有EF6的.NET 4.6.1类库，其中包含我的实体，领域模型，抽象和视图模型。 我在asp.net核心项目中添加了类库作为参考。 我将我的类库项目设置为我的启动项目，并启用迁移，甚至成功添加。 但是，一旦我做了更新数据库，我得到一个错误序列不包含匹配的元素。 所以我切换并创建了相同的项目，但没有拆分成类库和Web项目，现在只有一个asp.net mvc5项目，并且在
I created a new .NET project and added ADO.NET EF 6. I went through the EF wizard and choose Code First from Database. Then I selected a table. Let's call it "Product". This created "public partial class Product" and "public partial class Model1". I immediately created a LINQ query in my application to query the "Product" but I get the followin
我创建了一个新的.NET项目并添加了ADO.NET EF 6。 我通过EF向导并选择了从数据库中选择Code First。 然后我选择了一张桌子。 我们称之为“产品”。 这就创建了“公共部分类产品”和“公共部分类Model1”。 我立即在我的应用程序中创建了一个LINQ查询来查询“产品”，但我得到以下错误。 数据库中已经有一个名为'Product'的对象。 当我运行SQL配置文件时，我看到以下内容： CREATE TABLE [dbo]。[Product] ...
I am new to the C language and just learned about structs and pointers. My question is related to the offsetof macro I recently saw. I know how it works and the logic behind that. In the <stddef.h> file the definition is as follows: #define offsetof(type,member) ((unsigned long) &(((type*)0)->member)) My question is, if I have a struct as shown below: struct test { int fi
我对C语言很陌生，刚刚学习了结构和指针。 我的问题与我最近看到的宏观offsetof有关。 我知道它是如何工作的，以及背后的逻辑。 在<stddef.h>文件中，定义如下： #define offsetof(type,member) ((unsigned long) &(((type*)0)->member)) 我的问题是，如果我有一个结构如下所示： struct test { int field1: int field2: }; struct test var; 为什么我不能直接获取field2的地址为： char * p = (
When running command Update-Database , getting an error: Unable to update database to match the current model because there are pending changes and automatic migration is disabled. Either write the pending model changes to a code-based migration or enable automatic migration. Set DbMigrationsConfiguration.AutomaticMigrationsEnabled to true to enable automatic migration. You can use the Add-
运行命令Update-Database ，出现错误： 无法更新数据库以匹配当前模型，因为有未决的更改并且自动迁移已禁用。 将挂起的模型更改写入基于代码的迁移或启用自动迁移。 将DbMigrationsConfiguration.AutomaticMigrationsEnabled设置为true以启用自动迁移。 您可以使用“添加迁移”命令将挂起的模型更改写入基于代码的迁移。 在运行Add-Migration命令时，获得实体的迁移，该实体在之前提交到源代码时已被删除。 删除SQL数据