ios粘贴功能

　 NSString *path = [[NSBundlemainBundle] pathForResource:@"tmp_add"ofType:@"txt"];

    NSString *aStr = [NSStringstringWithContentsOfFile:path encoding:NSUTF8StringEncodingerror:nil];

    UIPasteboard *pasteboard = [UIPasteboardgeneralPasteboard];

    [pasteboard setString:aStr];