作者:0704034铜豌豆 | 来源:互联网 | 2022-12-01 23:09
我之前曾在一篇关于如何动态添加按钮的帖子上询问过.现在,我已经添加额外image
旁边的button
指示连接状态 的的客户机 .我有2个buttons
一个增加 ,另一个删除 的button
和image
.点击后,将有一个menuflyout
选择要删除的相应按钮.我的问题是我设法添加状态,image
但是当点击删除时 button
,menuflyout
运行exception
说明System.InvalidCastException
.
我的代码如下; 请帮忙.谢谢.
public Uri cOnnectedUri= new Uri("ms-appx:///Assets/icon-connected.png");
public Uri discOnnectedUri= new Uri("ms-appx:///Assets/icon-disconnected.png");
private void AddMenuFlyoutItem_Click(object sender, RoutedEventArgs e)
{
var item = sender as MenuFlyoutItem;
var deviceName = item.Text;
var deviceIP = item.Tag;
Button b = new Button();
b.Height = 30;
b.Width = 100;
b.VerticalAlignment = VerticalAlignment.Top;
b.HorizOntalAlignment= HorizontalAlignment.Left;
b.Margin = new Thickness(20, 20, 0, 0);
b.COntent= deviceName; // "Button " + buttonCounter;
b.Tag = deviceIP;
b.Click += AddMenuButton_Click;
Image stsImg = new Image();
BitmapImage bitmapImage = new BitmapImage();
//Uri cOnnectedUri= new Uri("ms-appx:///Assets/icon-connected");
//Uri discOnnectedUri= new Uri("ms-appx:///Assets/icon-disconnected");
bitmapImage.UriSource = connectedUri;
stsImg.Source = bitmapImage;
stsImg.Width = 20;
stsImg.Height = 20;
stsImg.VerticalAlignment = VerticalAlignment.Top;
stsImg.HorizOntalAlignment= HorizontalAlignment.Left;
stsImg.Margin = new Thickness(130, 20, 0, 0);
stsImg.Name = deviceName;
stsImg.Tag = deviceIP;
//Calculate the place of the button
int column = (int)(buttonCounter / 4);
int row = buttonCounter % 4;
//Check if you need to add a columns
if (row == 0)
{
ColumnDefinition col = new ColumnDefinition();
col.Width = new GridLength(column, GridUnitType.Auto);
myGrid.ColumnDefinitions.Add(col);
}
//Add the button
myGrid.Children.Add(b);
Grid.SetColumn(b, column);
Grid.SetRow(b, row);
myGrid.Children.Add(stsImg);
Grid.SetColumn(stsImg, column);
Grid.SetRow(stsImg, row);
buttonCounter++;
}
private void RemoveButton_Click(object sender, RoutedEventArgs e)
{
var menuFlyout = new MenuFlyout();
try
{
foreach (Button btn in myGrid.Children)
{
var row = Grid.GetRow(btn);
var col = Grid.GetColumn(btn);
//ButtonRow.Add(btn.Content.ToString(), row.ToString());
//ButtonCol.Add(btn.Content.ToString(), col.ToString());
var menuFlyoutItem = new MenuFlyoutItem() { Name = btn.Tag.ToString(), Text = btn.Content.ToString() };
menuFlyoutItem.Tag = btn.Content.ToString();
menuFlyoutItem.Click += RemoveMenuFlyoutItem_Click;
menuFlyout.Items.Add(menuFlyoutItem);
}
RemoveButton.Flyout = menuFlyout;
}
catch (Exception)
{
}
}
Martin Zikmu..
5
问题是foreach
:
foreach (Button btn in myGrid.Children)
当这样写的,它试图投出的所有子Grid
来Button
.这是不可能的,因为有些孩子不是按钮.但是你可以像这样编写循环:
foreach (Button btn in myGrid.Children.OfType())
的OfType
LINQ扩展方法将过滤输入枚举仅那些给定类型的物品.
1> Martin Zikmu..: 问题是foreach
:
foreach (Button btn in myGrid.Children)
当这样写的,它试图投出的所有子Grid
来Button
.这是不可能的,因为有些孩子不是按钮.但是你可以像这样编写循环:
foreach (Button btn in myGrid.Children.OfType())
的OfType
LINQ扩展方法将过滤输入枚举仅那些给定类型的物品.