ios - 在 iOS 应用程序中创建日志文件

Question

所以在我的应用程序中，我有一堆数据要写入日志文件，然后在我单击按钮时将其显示在 UITextView 中。我知道如何切换 UITextView，但我不知道如何创建和更新日志文件(在本地文件系统中)。感谢您的帮助。

Answer 1

基本思想是创建文件，并在每次记录新行时追加到文件中。你可以像这样很容易地做到这一点:

写入文件:

NSString *content = @"This is my log";

//Get the file path
NSString *documentsDirectory = [NSSearchPathForDirectoriesInDomains (NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
NSString *fileName = [documentsDirectory stringByAppendingPathComponent:@"myFileName.txt"];

//create file if it doesn't exist
if(![[NSFileManager defaultManager] fileExistsAtPath:fileName])
    [[NSFileManager defaultManager] createFileAtPath:fileName contents:nil attributes:nil];

//append text to file (you'll probably want to add a newline every write)
NSFileHandle *file = [NSFileHandle fileHandleForUpdatingAtPath:fileName];
[file seekToEndOfFile];
[file writeData:[content dataUsingEncoding:NSUTF8StringEncoding]];
[file closeFile];

阅读:

//get file path
NSString *documentsDirectory = [NSSearchPathForDirectoriesInDomains (NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
NSString *fileName = [documentsDirectory stringByAppendingPathComponent:@"myFileName.txt"];

//read the whole file as a single string
NSString *content = [NSString stringWithContentsOfFile:fileName encoding:NSUTF8StringEncoding error:nil];