Question

我有以下代码，它返回给定目录中文件名的NSArray。当目录存在时，这可以正常工作，但我想知道的是我如何首先检查 directoryPath 中的目录是否确实存在。

NSString *directoryPath = [documentsDirectory stringByAppendingPathComponent:folderName];
NSArray *directoryContents = [[NSFileManager defaultManager]contentsOfDirectoryAtPath:directoryPath error:nil];

Answer 1

使用NSFileManager的fileExistsAtPath：isDirectory：method。

Answer 2

fileExistsAtPath:isDirectory:

返回值如果指定路径中的文件存在，则为YES;如果文件不存在或无法确定其存在，则为NO。

Apple Documentation for NSFileManager

Answer 3

以下NSFileManger API可以提供所需的结果：

fileExistsAtPath:isDirectory:

Answer 4

使用此：

    NSFileManager *fileManager = [NSFileManager defaultManager];
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); 
    NSString *pathToDocumentsDir = [paths objectAtIndex:0];
    BOOL isDir;
    NSString *subfolder = [pathToDocumentsDir stringByAppendingPathComponent:fileExistsAtPath:YOUR_DIRECTORY_NAME];
    if (![fileManager fileExistsAtPath:subfolder isDirectory:&isDir]) {

//No directory exist
         [fileManager createDirectoryAtPath:subfolder withIntermediateDirectories:NO attributes:nil error:nil];
    }
else{
//directory exist
}

Answer 5

示例代码：

NSString *directoryPath = [documentsDirectory stringByAppendingPathComponent:folderName];
BOOL isDirectory;
BOOL isExists = [[NSFileManager defaultManager] fileExistsAtPath:directoryPath isDirectory:&isDirectory];
if (isExists) {
    /* file exists */
    if (isDirectory) {
        /* file is a directory */

    }
 }

Answer 6

NSFileManager类有一个内置方法，用于检查路径中是否存在文件。

功能如下：

[fileManagerObject fileExistsAtPath : @"PUT_YOUR_FILE_PATH_HERE" isDirectory : YES]; //If its a file that you're looking to check then put isDirectory as NO, but if its a folder then enter YES as the parameter

以下是您在代码中通常使用它的方法：

NSFileManager *fileManager = [[NSFileManager alloc] init];
if([fileManager fileExistsAtPath:@"FILE_PATH_HERE" isDirectory:NO] == YES)
{
   //Yes. The file exists, continue with your operation.
}
else
{
   //No. The file doesn't exist.
}

如果目录未退出，则使用NSFileManager返回

6 个答案: