使用Clipboard.SetText复制空字符串（字符串）

Question

Clipboard.SetText("") throws me an error - "Value cannot be null". So how do I copy an empty string using Clipboard.SetText ?

I have already done Clipboard.Clear() . It does clear the clipboard, but it doesn't help me to paste an empty string

Any suggestions?

Answer 1

If you try to save null or an empty string using Clipboard.SetText it will never work.

See Clipboard.SetText Method (String) (MSDN). It mentions ArgumentNullException is thrown if the text is null or Empty for Clipboard.SetText .

Hence you cannot achieve what you are trying to achieve.

Answer 2

I think you need to do

Clipboard.Clear()

From MSDN

Clears any data from the system Clipboard.

Answer 3

See Clipboard.Clear Method (System.Windows.Forms) (MSDN).

Clipboard.Clear();

will clear the clipboard, so you will "paste" an empty string.

Answer 4

Reference PresentationCore and call System.Windows.Clipboard.SetText(string) instead of System.Windows.Forms.Clipboard.SetText(string) . I used clipview to verify that System.Windows.Clipboard.SetText(""); (which throws no exception) stores the empty string into the clipboard.

This method it saves you from having to conditionally call Clear() or SetText() depending on what string you are trying to effectively set into clipboard. This is especially useful if you're trying to write code to set the clipboard to any string value without knowing ahead of time whether or not the empty string needs to be supported. Ie, this method enables you to avoid treating the empty string like a special case (IMO, it shouldn't be a special case because that's just confusing).

Additionally, as can be seen with clipview, Clear() actually empties out the clipboard instead of placing an empty string in it. Calling System.Windows.Clipboard.SetText("") actually puts an empty string value into clipboard. When you paste, the target application can tell the difference and actually behave differently if it wants to.