iOS csv附件到电子邮件

Question

我可以使用我的iOS应用程序成功添加附件到电子邮件，但仅当我硬编码文件名时，否则附件中没有数据。

这有效：

(IBAction)sendEmail:(id)sender
{
transectNameString = [[NSUserDefaults standardUserDefaults] objectForKey:@"dipstransect"];
transectFileExt = [NSString stringWithFormat:@".csv"];
NSString *string1 = transectNameString;
NSString *string2 = @" Drops";
NSString *string3 = transectFileExt;
NSString *tempstring1 = [string1 stringByAppendingString:string2];
setTransectName = [tempstring1 stringByAppendingString:string3];

MFMailComposeViewController *mailComposer;
NSArray *emailAddresses;

mailComposer = [MFMailComposeViewController new];
emailAddresses = @[];
mailComposer.mailComposeDelegate = self;
[mailComposer setToRecipients:emailAddresses];

filePath = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
fileName = @"Paynes Drops.csv";
fileAtPath = [filePath stringByAppendingPathComponent:fileName];
NSData *fileData = [NSData dataWithContentsOfFile:fileAtPath];

[mailComposer addAttachmentData:fileData mimeType:@"text/csv" fileName:fileName];

[self presentViewController:mailComposer animated:YES completion:nil];

}

这不起作用：

(IBAction)sendEmail:(id)sender
{
transectNameString = [[NSUserDefaults standardUserDefaults] objectForKey:@"dipstransect"];
transectFileExt = [NSString stringWithFormat:@".csv"];
NSString *string1 = transectNameString;
NSString *string2 = @" Drops";
NSString *string3 = transectFileExt;
NSString *tempstring1 = [string1 stringByAppendingString:string2];
setTransectName = [tempstring1 stringByAppendingString:string3];

MFMailComposeViewController *mailComposer;
NSArray *emailAddresses;

mailComposer = [MFMailComposeViewController new];
emailAddresses = @[];
mailComposer.mailComposeDelegate = self;
[mailComposer setToRecipients:emailAddresses];

filePath = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
fileName = setTransectName;
fileAtPath = [filePath stringByAppendingPathComponent:fileName];
NSData *fileData = [NSData dataWithContentsOfFile:fileAtPath];

[mailComposer addAttachmentData:fileData mimeType:@"text/csv" fileName:fileName];

[self presentViewController:mailComposer animated:YES completion:nil];

}

导致问题的fileName是什么？

Answer 1

我将以下行移至ViewDidLoad语句并且它有效。

• （无效）viewDidLoad中 {

  transectNameString = [[NSUserDefaults standardUserDefaults] objectForKey：@“dipstransect”];

  [super viewDidLoad]; //加载视图后进行任何其他设置。 }

• （IBAction为）sendEmail：（ID）发送方 {

  MFMailComposeViewController * mailComposer; NSArray * emailAddresses;

  mailComposer = [MFMailComposeViewController new]; emailAddresses = @ []; mailComposer.mailComposeDelegate = self; [mailComposer setToRecipients：emailAddresses];

  filePath = [NSSearchPathForDirectoriesInDomains（NSDocumentDirectory，NSUserDomainMask，YES）objectAtIndex：0];

  transectFileExt = [NSString stringWithFormat：@“。csv”]; NSString * string2 = @“Drops”;

  NSString * tempString1 = [transectNameString stringByAppendingString：string2]; NSString * tempString2 = [tempString1 stringByAppendingString：transectFileExt];

  fileName = tempString2; fileAtPath = [filePath stringByAppendingPathComponent：fileName]; NSData * fileData = [NSData dataWithContentsOfFile：fileAtPath];

  [mailComposer addAttachmentData：fileData mimeType：@“text / csv”fileName：fileName];

  transectFile2Ext = [NSString stringWithFormat：@“。txt”]; NSString * string4 = @“Drops Notes”;

  NSString * tempString3 = [transectNameString stringByAppendingString：string4]; NSString * tempString4 = [tempString3 stringByAppendingString：transectFile2Ext];

  file2Name = tempString4; file2AtPath = [filePath stringByAppendingPathComponent：file2Name]; NSData * file2Data = [NSData dataWithContentsOfFile：file2AtPath];

  [mailComposer addAttachmentData：file2Data mimeType：@“text / txt”fileName：file2Name];

  [self presentViewController：mailComposer animated：YES completion：nil];

}