iOS應用程序只能在為該改程序創建的文件系統中讀取文件，不可以去其它地方訪問，此區域被成為沙盒，所以所有的非代碼文件都要保存在此，例如圖像，圖標，聲音，映像，屬性列表，文本文件等。
沙盒文件的目錄結構:
Documents
-
Library
Caches
Preferences
tmp
沙盒下各文件夾保存內容的區別
-
Documents：保存應用運行時生成的
需要持久化的數據，iTunes同步設備時會備份該目錄。例如，游戲應用可以將游戲存檔保存在該目錄下。如果用戶將緩存存放在這個文件夾下，會導致應用審核無法通過。 -
tmp：保存應用運行時所需要的
臨時數據,使用完畢后再將相應的文件從該目錄刪除。應用沒有運行時，系統也可能會清除該目錄下的文件。iTunes同步設備時不會備份該目錄。 -
Library/Caches：保存應用運行時生成的
需要持久化的數據，iTunes同步設備時不會備份該目錄。一般存儲體積大，不需要備份的非重要數據。 -
Library/Preference：保存應用的所有
偏好設置，iOS的Settings(設置)應用會在該目錄中查找應用的設置信息。iTunes同步設備時會備份該目錄。
獲取程序的Home目錄
NSString *homeDirectory = NSHomeDirectory();
NSLog(@"path:%@", homeDirectory);
獲取document目錄
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *path = [paths objectAtIndex:0];
獲取Cache目錄
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES);
NSString *path = [paths objectAtIndex:0];
獲取Library目錄
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSLibraryDirectory, NSUserDomainMask, YES);
NSString *path = [paths objectAtIndex:0];
獲取Tmp目錄
NSString *tmpDir = NSTemporaryDirectory();
NSLog(@"%@", tmpDir);
創建文件夾
-(void)createDirectory{
NSString *documentsPath =[self getDocumentsPath];
NSFileManager *fileManager = [NSFileManager defaultManager];
NSString *iOSDirectory = [documentsPath stringByAppendingPathComponent:@"/iOS"];
BOOL isSuccess = [fileManager createDirectoryAtPath:iOSDirectory withIntermediateDirectories:YES attributes:nil error:nil];
if (isSuccess) {
NSLog(@"success");
} else {
NSLog(@"fail");
}
}
創建文件
-(void)createFile{
NSString *documentsPath =[self getDocumentsPath];
NSFileManager *fileManager = [NSFileManager defaultManager];
NSString *iOSPath = [documentsPath stringByAppendingPathComponent:@"iOS.txt"];
BOOL isSuccess = [fileManager createFileAtPath:iOSPath contents:nil attributes:nil];
if (isSuccess) {
NSLog(@"success");
} else {
NSLog(@"fail");
}
}
寫文件
-(void)writeFile{
NSString *documentsPath =[self getDocumentsPath];
NSString *iOSPath = [documentsPath stringByAppendingPathComponent:@"iOS.txt"];
NSString *content = @"我要寫數據啦";
BOOL isSuccess = [content writeToFile:iOSPath atomically:YES encoding:NSUTF8StringEncoding error:nil];
if (isSuccess) {
NSLog(@"write success");
} else {
NSLog(@"write fail");
}
}
NSString * fileName = @"testFileNSFileManager.txt";
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
//獲取文件路徑
NSString *path = [documentsDirectory stringByAppendingPathComponent:fileName];
//待寫入的數據
NSString *temp = @"nihao 世界";
int dataInt = 1234;
float dataFloat = 3.14f;
//創建數據緩沖
NSMutableData *writer = [[NSMutableData alloc] init];
//將字符串添加到緩沖中
[writer appendData:[temp dataUsingEncoding:NSUTF8StringEncoding]];
//將其他數據添加到緩沖中
[writer appendBytes:&dataInt length:sizeof(dataInt)];
[writer appendBytes:&dataFloat length:sizeof(dataFloat)];
//將緩沖的數據寫入到文件中
[writer writeToFile:path atomically:YES];
讀取文件內容
-(void)readFileContent{
NSString *documentsPath =[self getDocumentsPath];
NSString *iOSPath = [documentsPath stringByAppendingPathComponent:@"iOS.txt"];
NSString *content = [NSString stringWithContentsOfFile:iOSPath encoding:NSUTF8StringEncoding error:nil];
NSLog(@"read success: %@",content);
}
//讀取數據：
int intData;
float floatData = 0.0;
NSString *stringData;
NSData *reader = [NSData dataWithContentsOfFile:path];
stringData = [[NSString alloc] initWithData:[reader subdataWithRange:NSMakeRange(0, [temp length])]
encoding:NSUTF8StringEncoding];
[reader getBytes:&intData range:NSMakeRange([temp length], sizeof(intData))];
[reader getBytes:&floatData range:NSMakeRange([temp length] + sizeof(intData), sizeof(floatData))];
NSLog(@"stringData:%@ intData:%d floatData:%f", stringData, intData, floatData);
判斷文件是否存在
- (BOOL)isSxistAtPath:(NSString *)filePath{
NSFileManager *fileManager = [NSFileManager defaultManager];
BOOL isExist = [fileManager fileExistsAtPath:filePath];
return isExist;
}
計算文件大小
- (unsigned long long)fileSizeAtPath:(NSString *)filePath{
NSFileManager *fileManager = [NSFileManager defaultManager];
BOOL isExist = [fileManager fileExistsAtPath:filePath];
if (isExist){
unsigned long long fileSize = [[fileManager attributesOfItemAtPath:filePath error:nil] fileSize];
return fileSize;
} else {
NSLog(@"file is not exist");
return 0;
}
}
計算整個文件夾中所有文件大小
- (unsigned long long)folderSizeAtPath:(NSString*)folderPath{
NSFileManager *fileManager = [NSFileManager defaultManager];
BOOL isExist = [fileManager fileExistsAtPath:folderPath];
if (isExist){
NSEnumerator *childFileEnumerator = [[fileManager subpathsAtPath:folderPath] objectEnumerator];
unsigned long long folderSize = 0;
NSString *fileName = @"";
while ((fileName = [childFileEnumerator nextObject]) != nil){
NSString* fileAbsolutePath = [folderPath stringByAppendingPathComponent:fileName];
folderSize += [self fileSizeAtPath:fileAbsolutePath];
}
return folderSize / (1024.0 * 1024.0);
} else {
NSLog(@"file is not exist");
return 0;
}
}
刪除文件
-(void)deleteFile{
NSString *documentsPath =[self getDocumentsPath];
NSFileManager *fileManager = [NSFileManager defaultManager];
NSString *iOSPath = [documentsPath stringByAppendingPathComponent:@"iOS.txt"];
BOOL isSuccess = [fileManager removeItemAtPath:iOSPath error:nil];
if (isSuccess) {
NSLog(@"delete success");
}else{
NSLog(@"delete fail");
}
}
移動文件
- (void)moveFileName
{
NSString *documentsPath =[self getDocumentsPath];
NSFileManager *fileManager = [NSFileManager defaultManager];
NSString *filePath = [documentsPath stringByAppendingPathComponent:@"iOS.txt"];
NSString *moveToPath = [documentsPath stringByAppendingPathComponent:@"iOS.txt"];
BOOL isSuccess = [fileManager moveItemAtPath:filePath toPath:moveToPath error:nil];
if (isSuccess) {
NSLog(@"rename success");
}else{
NSLog(@"rename fail");
}
}
重命名
- (void)renameFileName
{
//通過移動該文件對文件重命名
NSString *documentsPath =[self getDocumentsPath];
NSFileManager *fileManager = [NSFileManager defaultManager];
NSString *filePath = [documentsPath stringByAppendingPathComponent:@"iOS.txt"];
NSString *moveToPath = [documentsPath stringByAppendingPathComponent:@"rename.txt"];
BOOL isSuccess = [fileManager moveItemAtPath:filePath toPath:moveToPath error:nil];
if (isSuccess) {
NSLog(@"rename success");
}else{
NSLog(@"rename fail");
}
}
