Metro style App ContextMenu Summary

最新推荐文章于 2023-07-09 13:36:45 发布

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最新推荐文章于 2023-07-09 13:36:45 发布

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原文链接：https://yq.aliyun.com/articles/360114

本文提供了在UWP应用中实现右键菜单及文本选择功能的代码示例，包括获取元素边界、显示上下文菜单及复制选定文本等实用功能。

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Metro style App ContextMenu Summary。

Fist let us see the effect pictures。

Picture 1.

Picture 2.

Get the frameworkElement Rect。

public static Rect GetElementRect(FrameworkElement element)
{

    GeneralTransform buttonTransform = element.TransformToVisual(null);

    Point point = buttonTransform.TransformPoint(new Point());

    return new Rect(point, new Size(element.ActualWidth, element.ActualHeight));
}

Next is a image righttap event。

private async void AttachmentImage_RightTapped(object sender, RightTappedRoutedEventArgs e)
{

    var menu = new PopupMenu();

    menu.Commands.Add(new UICommand("Open with", (command) =>

    {

        //ToDo:function

    }));

    menu.Commands.Add(new UICommand("Save attachment", (command) =>

    {

        //ToDo:function

    }));
 
    var chosenCommand = await menu.ShowForSelectionAsync(GetElementRect((FrameworkElement)sender));

    if (chosenCommand == null) 

    {

        // The command is null if no command was invoked.

        //ToDo：function

    }
}

2.Another sample

returns a rect for selected text

// returns a rect for selected text

private Rect GetTextboxSelectionRect(TextBox textbox)
{

    Rect rectFirst, rectLast;

    if (textbox.SelectionStart == textbox.Text.Length)

    {

        rectFirst = textbox.GetRectFromCharacterIndex(textbox.SelectionStart - 1, true);

    }

    else

    {

        rectFirst = textbox.GetRectFromCharacterIndex(textbox.SelectionStart, false);

    }
 
    int lastIndex = textbox.SelectionStart + textbox.SelectionLength;

    if (lastIndex == textbox.Text.Length)

    {

        rectLast = textbox.GetRectFromCharacterIndex(lastIndex - 1, true);

    }

    else

    {

        rectLast = textbox.GetRectFromCharacterIndex(lastIndex, false);

    }
 
    GeneralTransform buttonTransform = textbox.TransformToVisual(null);

    Point point = buttonTransform.TransformPoint(new Point());
 
    return new Rect(point.X + rectFirst.Left,

        point.Y + rectFirst.Top,

        rectLast.Right - rectFirst.Left,

        rectLast.Bottom - rectFirst.Top);
}

Next is a TextBox ContextMenuOpening event.

private async void ReadOnlyTextBox_ContextMenuOpening(object sender, ContextMenuEventArgs e)
{

    e.Handled = true;

    TextBox textbox = (TextBox)sender;

    if (textbox.SelectionLength > 0)

    {

        var menu = new PopupMenu();

        menu.Commands.Add(new UICommand("Copy", null, 1));

        menu.Commands.Add(new UICommandSeparator());

        menu.Commands.Add(new UICommand("Highlight", null, 2));

        menu.Commands.Add(new UICommand("Look up", null, 3));
 
        Rect rect = GetTextboxSelectionRect(textbox);

        var chosenCommand = await menu.ShowForSelectionAsync(rect);

        if (chosenCommand != null)

        {

            switch ((int)chosenCommand.Id)

            {

                case 1:

                    //Next is copy function

                    String selectedText = ((TextBox)sender).SelectedText;

                    var dataPackage = new DataPackage();

                    dataPackage.SetText(selectedText);

                    Clipboard.SetContent(dataPackage); 

                    break;
 
                case 2:

                    //Todo:function

                    break;
 
                case 3:

                    //Todo:function

                    break;

            }

        }

        else

        {

            //Todo:function

        }

    }

    else

    {

        //Todo:function

    }
}