file-handling

问题 If this is the code in opening a textfile "word.txt" in my solution explorer. Stream txtStream = Application.GetResourceStream(new Uri("/sample;component/word.txt", UriKind.Relative)).Stream; using (StreamReader sr = new StreamReader(txtStream)) { string jon; while (!sr.EndOfStream) { jon = sr.ReadLine(); mylistbox.ItemSource = jon; } } How do i write and append in the existing textfile? 回答1: Here is an example public static void WriteBackgroundSetting(string currentBackground) { const string

问题 I created a file named "test" but I'm unable to open it using fopen. Here is the code- #include<stdio.h> int main() { FILE *fp; fp=fopen("test.txt","r"); if(fp==NULL) { perror("Error: "); } fclose(fp); return 0; } When I run the above code, I get the following output: Error: Invalid argument What could be the reason? When does perror return "Invalid argument" error message? 回答1: Have a look at man fopen: EINVAL The mode provided to fopen(), fdopen(), or freopen() was invalid. Probably test

问题 I have a test.txt that contains: - anything1 go - anything2 go And i wanna replace the '-' with my list and some query. Here is my code: x = ['1', '2'] i=0 with open("test.txt", "r") as fin: with open("result.txt", "w") as fout: for line in fin: fout.write(line.replace('-','\nuse '+(str(x[i]))+'\ngo\n')) i+=i But my result is: use 1 go anything1 go use 1 go anything2 go I need that the second 'use' be 'use 2' and not 'use 1'. How I can fix this? Thanks 回答1: Try this instead: i = (x for x in [

问题 I read builtin function iter 's example in Built-in Functions — Python 3.7.0 documentation with open('mydata.txt') as fp: for line in iter(fp.readline, ''): process_line(line) I could not figure out what's the advantage over the following: with open('mydata.txt') as fp: for line in fp: process_line(line) Could you please provide any hints? 回答1: Both will iterate over a generator, without loading the whole file into memory, but the iter() version is demonstrating the use of the second argument

问题 I wrote the following code to input numbers from a file however the last number gets printed twice which I find perplexing. What could be the possible answer. Thanks in advance. code: #include<iostream> #include<fstream> using namespace std; int main() { int x; ifstream f; f.open("note"); while(!f.eof()){ f>>x; cout<<x<<endl; } return 0; } gives output: 1 2 3 4 5 5 the contents of file note are: 1 2 3 4 5 回答1: Every solution so far presented has a good explanation of why the OP code is wrong.

问题 I have a Java Class UpdateStats in WEB-INF/Classes directory of a dynamic web application.This class has a function writeLog() which writes some logs to a text file.I want this text file to be in webcontent directory.Thus everytime the function is called updates stats are written in that text file. The problem is how to give the path of that text file in webcontent directory from within that function,which resides in WEB-INF/Classes directory. 回答1: You can get your webapp root directory from

问题 How can I know the size of qt data types in bytes; including QString objects if these data types were written on some QFile. I have to implement sizeOf() function in the Student class as below; something like we sizeof(struct student) in C. Student class #include<QtCore> class Student { public: QString name,fname; quint8 age,weight,clss; Student(){ } /*the following function should return the size of this object in bytes; I will use QDataStream & operator<<(QDataStream &out, Student &f)

问题 I've a file on which I require multiple operations. Sometimes I just want to append data at the end of the file, sometimes I just want to read from the file, and sometimes, I want to erase all the data and write form the beginning of the file. And then, I again need to append data at the end of file. I'm using following code: ofstream writeToTempFile; ifstream readFromTempFile; writeToTempFile.open("tempFile.txt", ios::app | ios::out); readFromTempFile.open("tempFile.txt", ios::in); //

问题 I am making a directory to store all uploaded files in my spring boot app on startup. The path of this directory is stored in application.properties file. I am trying to read this path and create a directory on startupof project. I am not able to get the path while creating a directory on startup. application.properties upload.path = "/src/main/resources" StorageProperties.java import org.springframework.boot.context.properties.ConfigurationProperties; @ConfigurationProperties(prefix =

问题 I am trying to allow for files to be uploaded by users in on my django site. I started with the example command from the django documentation, input into views.py, independently of a form or model and just referred to in the template (and modified it so that multiple files can be uploaded at once,): def Upload(request): for count, x in enumerate(request.FILES.getlist("files")):# allows for multiple iterations/files def process(): with open('/Users/Deirdre/bing/upload/media/file_', + str(count