NSStringPboardType给出的xml plist不是我想要的字符串

NSString *text = @"My Text";
NSLog(@"%@", text);

我在控制台收到“我的短信”。然后:

[pboard setPropertyList: text forType: NSStringPboardType];

如果我把它拖到文本编辑器(TextWrangler,TextEdit)中,我会得到:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<string>My Text</string>
</plist>