iPad應用程序 - 生成文本文件

Question

有人能解釋並給出示例代碼做在我的iPad應用程序下面的步驟：

1. 做一些事情在我的應用程序，從而產生一些數據（字符串）
2. 寫數據到一個文本文件
3. 能在我的iPad插上我的電腦，並抓住這些文本文件從

我怎樣才能做到這一點？

Answer 1

對於您的plist文件在文件中使用的字符串寫入此

NSString *str = @"your string"; 
NSArray* paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); 
NSString* documentsDirectory = [paths objectAtIndex:0]; 
NSString* filePath = [documentsDirectory stringByAppendingPathComponent:@"data.txt"]; 
NSError *error; 
[str writeToFile:filePath atomically:YES encoding:NSUTF8StringEncoding error:&error]; 

然後設置Application supports iTunes file sharing關鍵YES。
當你從那裏的iTunes連接您的設備，您可以保存您的data.txt
Here is the video how to get files from iTunes

---

編輯的要求。

NSUserDefaults *deflt = [NSUserDefaults standardUserDefaults]; 
//this number file is saved, I'm not saving the file name as data0.txt. 
//The first file to be saved is data1.txt 
int num = [deflt integerForKey:@"fileNameNum"]; 
num++; 
NSString *fileName = [NSString stringWithFormat:@"data%d.txt",num];; 
NSString *str = @"your string"; 
NSArray* paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); 
NSString* documentsDirectory = [paths objectAtIndex:0]; 
NSString* filePath = [documentsDirectory stringByAppendingPathComponent:fileName]; 
NSError *error = nil; 
[str writeToFile:filePath atomically:YES encoding:NSUTF8StringEncoding error:&error]; 
if (error == nil) { 
    //Save the number of the file that you have save in doc directory 
    [deflt setInteger:num forKey:@"fileNameNum"]; 
}