关于文件处理的问题

Question

我遇到了以下问题:我正在尝试创建一个文件与以下代码:

NSString *homeDirectory = NSHomeDirectory();
NSString *documentDirectory = [homeDirectory stringByAppendingPathComponent:@"Documents"];
NSString *filePath = [documentDirectory stringByAppendingPathComponent:@"Test.txt"];
NSFileHandle *savedFile = nil;
savedFile = [[NSFileHandle FileHandleForWritingAtPath:filePath]retain];
NSString *data = @"testmessage";
[savedFile writeData:[string dataUsingEncoding:NSUTF8StringEncoding]];
[savedFile synchronizeFile];
[savedFile closeFile];

我的问题如下。在MAC上运行这个程序不会给我任何错误。但文件本身似乎不存在，或者至少无法定位。我需要找到并访问该文件，并且我必须能够使用移动iOS设备将其导出到我的Mac

thanks in advance:)

h4wkeye

Answer 1

您需要检查savedFile是否为nil(参见此处的文档)。

NSString *homeDirectory = NSHomeDirectory();
NSString *documentDirectory = [homeDirectory stringByAppendingPathComponent:@"Documents"];
NSString *filePath = [documentDirectory stringByAppendingPathComponent:@"Test.txt"];
NSFileHandle *savedFile = nil;
savedFile = [[NSFileHandle fileHandleForWritingAtPath:filePath]retain];
if (nil == savedFile) {
    NSLog(@"Could not create saved file at %@", filePath);
}
NSString *data = @"testmessage";
[savedFile writeData:[string dataUsingEncoding:NSUTF8StringEncoding]];
[savedFile synchronizeFile];
[savedFile closeFile];