不兼容的指针类型将nsstring传递给const char类型的形参(错误)

Question

我使用的是core data和libxl。每当我在libxl中实现核心数据字符串时，它就会给我错误"不兼容的指针类型将nsstring传递给const char类型的参数"

不知道为什么…

这是我的代码，namelabel。text是核心数据NSString，它将NSString传递给const char类型的形参，产生错误不兼容的指针类型。

- (IBAction)createExcel:(id)sender
{
    NSLog(@"createExcel");
    BookHandle book = xlCreateBook(); // use xlCreateXMLBook() for working with xlsx files
    SheetHandle sheet = xlBookAddSheet(book, "Sheet1", NULL);
    xlSheetWriteStr(sheet, 1, 1, namelabel.text, 0);
    xlSheetWriteNum(sheet, 4, 1, 1000, 0);
    xlSheetWriteNum(sheet, 5, 1, 2000, 0);
    FontHandle font = xlBookAddFont(book, 0);
    xlFontSetColor(font, COLOR_RED);
    xlFontSetBold(font, true);
    FormatHandle boldFormat = xlBookAddFormat(book, 0);
    xlFormatSetFont(boldFormat, font);
    xlSheetWriteFormula(sheet, 6, 1, "SUM(B5:B6)", boldFormat);
    FormatHandle dateFormat = xlBookAddFormat(book, 0);
    xlFormatSetNumFormat(dateFormat, NUMFORMAT_DATE);
    xlSheetWriteNum(sheet, 8, 1, xlBookDatePack(book, 2011, 7, 20, 0, 0, 0, 0), dateFormat);
    xlSheetSetCol(sheet, 1, 1, 12, 0, 0);
    NSString *documentPath =
    [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask, YES) objectAtIndex:0];
    NSString *filename = [documentPath stringByAppendingPathComponent:@"insuranceclaim.xls"];
    xlBookSave(book, [filename UTF8String]);
    xlBookRelease(book);
    if (![MFMailComposeViewController canSendMail]) {
        //Show alert that device cannot send email, this is because an email account     hasn't been setup.
    }
    else {
        //**EDIT HERE**
        //Use this to retrieve your recently saved file
        NSString *documentPath = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask, YES) objectAtIndex:0];
        NSString *filename = [documentPath stringByAppendingPathComponent:@"insuranceclaim.xls"];
        //**END OF EDIT**
        NSString *mimeType = @"application/vnd.ms-excel"; //This should be the MIME type for els files. May want to double check.
        NSData *fileData = [NSData dataWithContentsOfFile:filename];
        NSString *fileNameWithExtension = @"insuranceclaim.xls"; //This is what you want the file to be called on the email along with it's extension:
        //If you want to then delete the file:
        NSError *error;
        if (![[NSFileManager defaultManager] removeItemAtPath:filename error:&error])
            NSLog(@"ERROR REMOVING FILE: %@", [error localizedDescription]);

        //Send email
        MFMailComposeViewController *mailMessage = [[MFMailComposeViewController alloc] init];
        [mailMessage setMailComposeDelegate:self];
        [mailMessage addAttachmentData:fileData mimeType:mimeType fileName:fileNameWithExtension];
        [self presentViewController:mailMessage animated:YES completion:nil];
    }

}

- (void)mailComposeControllerone:(MFMailComposeViewController *)controller didFinishWithResult:(MFMailComposeResult)result error:(NSError *)error {
    switch (result)
    {
        case MFMailComposeResultCancelled:
            NSLog(@"Mail cancelled: you cancelled the operation and no email message was queued.");
            break;
        case MFMailComposeResultSaved:
            NSLog(@"Mail saved: you saved the email message in the drafts folder.");
            break;
        case MFMailComposeResultSent:
            NSLog(@"Mail send: the email message is queued in the outbox. It is ready to send.");
            break;
        case MFMailComposeResultFailed:
            NSLog(@"Mail failed: the email message was not saved or queued, possibly due to an error.");
            break;
        default:
            NSLog(@"Mail not sent.");
            break;
    }
    [controller dismissViewControllerAnimated:YES completion:nil];
}
@end

Answer 1

转换为const char *试试

const char *s = [namelabel.text UTF8String];

，传递到你需要的地方。

编辑:

xlSheetWriteStr(sheet, 1, 1, [namelabel.text UTF8String], 0);