保存NSArray [英] Saving a NSArray

问题描述

我想将NSArray保存为文件或可能使用用户默认值。

I would like to save an NSArray either as a file or possibly use user defaults. Here's what I am hoping to do.

1. 检索已保存的NSArray（如果有）。

删除保存的数据（如果有）。

保存NSArray。 >

这是可能的，如果是这样，我该怎么办？

Is this possible, and if so how should I do this?

推荐答案

NSArray提供了两种方法来完成你想要的： initWithContentsOfFile：和 writeToFile：atomically：

NSArray provides you with two methods to do exactly what you want: initWithContentsOfFile: and writeToFile:atomically:

一个简短的示例可能如下所示：

A short example might look like this:

//Creating a file path under iOS:
//1) Search for the app's documents directory (copy+paste from Documentation)
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
//2) Create the full file path by appending the desired file name
NSString *yourArrayFileName = [documentsDirectory stringByAppendingPathComponent:@"example.dat"];

//Load the array
NSMutableArray *yourArray = [[NSMutableArray alloc] initWithContentsOfFile: yourArrayFileName];
if(yourArray == nil)
{
    //Array file didn't exist... create a new one
    yourArray = [[NSMutableArray alloc] initWithCapacity:10];

    //Fill with default values
}
...
//Use the content
...
//Save the array
[yourArray writeToFile:yourArrayFileName atomically:YES];

这篇关于保存NSArray的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！