如何在iOS上写入文件？我正在尝试使用下面的代码来做，但是我做错了什么：
char *saves = "abcd";
NSData *data = [[NSData alloc] initWithBytes:saves length:4];
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *appFile = [documentsDirectory stringByAppendingPathComponent:@"MyFile"];
[data writeToFile:appFile atomically:YES];
我在资源上创建了MyFile.txt。
Answers:
您的代码正在我的末端运行，我已经对其进行了测试。您在哪里查看更改？使用文档目录路径。获取路径-
NSLog(@"%@",documentsDirectory);
并从控制台复制路径，然后打开finder并按Cmd + shift + g并在此处粘贴路径，然后打开文件
可能对您有用。
//Method writes a string to a text file
-(void) writeToTextFile{
//get the documents directory:
NSArray *paths = NSSearchPathForDirectoriesInDomains
(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
//make a file name to write the data to using the documents directory:
NSString *fileName = [NSString stringWithFormat:@"%@/textfile.txt",
documentsDirectory];
//create content - four lines of text
NSString *content = @"One\nTwo\nThree\nFour\nFive";
//save content to the documents directory
[content writeToFile:fileName
atomically:NO
encoding:NSUTF8StringEncoding
error:nil];
}
//Method retrieves content from documents directory and
//displays it in an alert
-(void) displayContent{
//get the documents directory:
NSArray *paths = NSSearchPathForDirectoriesInDomains
(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
//make a file name to write the data to using the documents directory:
NSString *fileName = [NSString stringWithFormat:@"%@/textfile.txt",
documentsDirectory];
NSString *content = [[NSString alloc] initWithContentsOfFile:fileName
usedEncoding:nil
error:nil];
//use simple alert from my library (see previous post for details)
[ASFunctions alert:content];
[content release];
}
迅速
func saveFile() {
let paths = NSSearchPathForDirectoriesInDomains(.DocumentDirectory, .UserDomainMask, true)
let documentsDirectory = paths[0] as! String
let fileName = "\(documentsDirectory)/textFile.txt"
let content = "Hello World"
content.writeToFile(fileName, atomically: false, encoding: NSUTF8StringEncoding, error: nil)
}
func loadFile() {
let paths = NSSearchPathForDirectoriesInDomains(.DocumentDirectory, .UserDomainMask, true)
let documentsDirectory = paths[0] as! String
let fileName = "\(documentsDirectory)/textFile.txt"
let content: String = String(contentsOfFile: fileName, encoding: NSUTF8StringEncoding, error: nil)!
println(content)
}
迅捷2
func saveFile() {
let paths = NSSearchPathForDirectoriesInDomains(.DocumentDirectory, .UserDomainMask, true)
let documentsDirectory = paths[0]
let fileName = "\(documentsDirectory)/textFile.txt"
let content = "Hello World"
do{
try content.writeToFile(fileName, atomically: false, encoding: NSUTF8StringEncoding)
}catch _ {
}
}
func loadFile()->String {
let paths = NSSearchPathForDirectoriesInDomains(.DocumentDirectory, .UserDomainMask, true)
let documentsDirectory = paths[0]
let fileName = "\(documentsDirectory)/textFile.txt"
let content: String
do{
content = try String(contentsOfFile: fileName, encoding: NSUTF8StringEncoding)
}catch _{
content=""
}
return content;
}
迅捷3
func saveFile() {
let paths = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)
let documentsDirectory = paths[0]
let fileName = "\(documentsDirectory)/textFile.txt"
let content = "Hello World"
do{
try content.write(toFile: fileName, atomically: false, encoding: String.Encoding.utf8)
}catch _ {
}
}
func loadFile()->String {
let paths = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)
let documentsDirectory = paths[0]
let fileName = "\(documentsDirectory)/textFile.txt"
let content: String
do{
content = try String(contentsOfFile: fileName, encoding: String.Encoding.utf8)
} catch _{
content=""
}
return content;
}