TextBox.Paste 事件

public:
 virtual event TextControlPasteEventHandler ^ Paste;

// Register
event_token Paste(TextControlPasteEventHandler const& handler) const;

// Revoke with event_token
void Paste(event_token const* cookie) const;

// Revoke with event_revoker
TextBox::Paste_revoker Paste(auto_revoke_t, TextControlPasteEventHandler const& handler) const;

public event TextControlPasteEventHandler Paste;

function onPaste(eventArgs) { /* Your code */ }
textBox.addEventListener("paste", onPaste);
textBox.removeEventListener("paste", onPaste);
- or -
textBox.onpaste = onPaste;

Public Custom Event Paste As TextControlPasteEventHandler 

<TextBox Paste="eventhandler"/>

事件類型

範例

本範例展示了如何處理 Paste 事件，將換行符改為逗號，貼入地址欄位。 否則，從多行複製的位址貼上會導致資料遺失。

<TextBox Header="Address" Paste="AddressTextBox_Paste"/>

private async void AddressTextBox_Paste(object sender, TextControlPasteEventArgs e)
{
    TextBox addressBox = sender as TextBox;
    if (addressBox != null)
    {
        // Mark the event as handled first. Otherwise, the
        // default paste action will happen, then the custom paste
        // action, and the user will see the text box content change.
        e.Handled = true;

        // Get content from the clipboard.
        var dataPackageView = Windows.ApplicationModel.DataTransfer.Clipboard.GetContent();
        if (dataPackageView.Contains(Windows.ApplicationModel.DataTransfer.StandardDataFormats.Text))
        {
            try
            {
                var text = await dataPackageView.GetTextAsync();

                // Remove line breaks from multi-line text and
                // replace with comma(,).
                string singleLineText = text.Replace("\r\n", ", ");

                // Replace any text currently in the text box.
                addressBox.Text = singleLineText;
            }
            catch (Exception)
            {
                // Ignore or handle exception as needed.
            }
        }
    }
}

這個範例展示了如何處理 Paste 事件，以限制貼入 Textbox 的字元數量。 如果剪貼簿上的文字長度超過文字框的最大長度，使用者會看到訊息。 使用者可以選擇以截斷文字繼續，或取消貼上操作。

<TextBox Paste="TextBox_Paste" MaxLength="10"/>

private async void TextBox_Paste(object sender, TextControlPasteEventArgs e)
{
    TextBox tb = sender as TextBox;
    if (tb != null)
    {
        // Mark the event as handled first. Otherwise, the
        // default paste action will happen, then the custom paste
        // action, and the user will see the text box content change.
        e.Handled = true;

        // Get content from the clipboard.
        var dataPackageView = Windows.ApplicationModel.DataTransfer.Clipboard.GetContent();
        if (dataPackageView.Contains(Windows.ApplicationModel.DataTransfer.StandardDataFormats.Text))
        {
            try
            {
                var text = await dataPackageView.GetTextAsync();
                if (text.Length > tb.MaxLength)
                {
                    // Pasted text is too long. Show a message to the user.
                    // Create the message dialog and set its content
                    var messageDialog = 
                        new Windows.UI.Popups.MessageDialog(
                            "Pasted text excedes maximum allowed (" 
                            + tb.MaxLength.ToString() + 
                            " characters). The text will be truncated.");

                    // Add commands to the message dialog.
                    messageDialog.Commands.Add(new UICommand("Continue", (command) =>
                    {
                        // Truncate the text to be pasted to the MaxLength of the text box.
                        string truncatedText = text.Substring(0, tb.MaxLength);
                        tb.Text = truncatedText;
                    }));
                    messageDialog.Commands.Add(new UICommand("Cancel", (command) =>
                    {
                        // Cancelled. Do nothing.
                    }));

                    // Set the command that will be invoked by default.
                    messageDialog.DefaultCommandIndex = 0;

                    // Set the command to be invoked when escape is pressed.
                    messageDialog.CancelCommandIndex = 1;

                    // Show the message dialog.
                    await messageDialog.ShowAsync();
                }
                else
                {
                    tb.Text = text;
                }                          
            }
            catch (Exception)
            {
                // Ignore or handle exception as needed.
            }
        }
    }
}

備註

Paste 事件發生在任何內容插入控制項之前。 你可以處理這個事件，檢查剪貼簿的內容，並在內容插入前執行任何操作。 如果你執行任何動作，請將事件 args 的 Handled 屬性設為 true;否則，則執行預設的貼上動作。 如果你把事件標記為已處理，就會假設應用程式已經處理了貼上操作，預設動作不會被執行。 你負責決定插入點和剪貼板內容，並自行插入內容。

你應該在程式碼執行自訂貼上動作前，在處理器裡把 Handled 屬性設 為 true 。 否則，先執行預設的貼上動作，接著執行自訂動作。 使用者可以看到內容在 文字框中變化。