Get the property value by its path

/// <summary>
/// walks the property path and gets the value of the property on the object 'value'
/// example: path = "Company.Address[1].City"
/// </summary>
/// <param name="value">object to parse the property value from</param>
/// <param name="path">path to the property</param>
public static object FollowPropertyPath(object value, string path)
{
    if (value == null) throw new ArgumentNullException("value");
    if (path == null) throw new ArgumentNullException("path");
 
    Type currentType = value.GetType();
 
    object obj = value;
    foreach (string propertyName in path.Split('.')) // split property path by "."
    {
        if (currentType != null)
        {
            PropertyInfo property = null;
            int brackStart = propertyName.IndexOf("["); // parsing out if the property is an indexer property
            int brackEnd = propertyName.IndexOf("]");
 
            property = currentType.GetProperty(brackStart > 0 ? propertyName.Substring(0, brackStart) : propertyName);
            obj = property.GetValue(obj, null);
 
            if (brackStart > 0) // just for indexer properties
            {
                string index = propertyName.Substring(brackStart + 1, brackEnd - brackStart - 1); // get the index
                // determine type of indexer property. extend the following if other types are required
                foreach (Type iType in obj.GetType().GetInterfaces())
                {
                    // http://stackoverflow.com/questions/852233/getting-values-of-a-generic-idictionary-using-reflection
                    if (iType.IsGenericType && iType.GetGenericTypeDefinition() == typeof(IDictionary<,>))
                    {
                        obj = typeof(ReflectorUtil).GetMethod("GetDictionaryElement")
                                                .MakeGenericMethod(iType.GetGenericArguments())
                                                .Invoke(null, new object[] { obj, index });
                        break;
                    }
                    if (iType.IsGenericType && iType.GetGenericTypeDefinition() == typeof(IList<>))
                    {
                        obj = typeof(ReflectorUtil).GetMethod("GetListElement")
                                                .MakeGenericMethod(iType.GetGenericArguments())
                                                .Invoke(null, new object[] { obj, index });
                        break;
                    }
                }
            }
            // allow for derived properties in the path (property.PropertyType will get the defined type, obj.GetType the actual one)
            currentType = obj != null ? obj.GetType() : null; //property.PropertyType; 
        }
        else return null;
    }
 
    return obj;
}
 
public static TValue GetDictionaryElement<TKey, TValue>(IDictionary<TKey, TValue> dict, object index)
{
    TKey key = (TKey)Convert.ChangeType(index, typeof(TKey), null);
    return dict[key];
}
 
public static T GetListElement<T>(IList<T> list, object index)
{
    return list[Convert.ToInt32(index)];
}

WPF Treeview Recursive Expand/Collapse

The following class contains an expansion method that allows for dynamic expansion and collapse of a WPF (untested with Silverlight, might work as well) TreeView. The second method parameter provides a way to define the depth of expansion/collapse.

public static class TreeViewExt
{
    /// <summary>
    /// Expands/collapses a treeview control recursively. Since for a hierarchical data template, the items will
    /// only be generated when displayed - and only then can be expanded, the method attaches an event to the 
    /// StatusChanged event of the ItemsContainerGenerator and waits until they are in fact generated to recursively
    /// call the expand method on these items.
    /// </summary>
    /// 
    /// <param name="itemsControl"> ItemsControl, can be treeview or treeviewitem </param>
    /// <param name="expand"> expand = false collapses, expand = true expands </param>
    /// <param name="levelDepth"> for levelDepth = int.MaxValue, the entire tree will be expanded/collapsed.  
    /// For any  other value n of levelDepth, only n levels away from the supplied itemsControl will be expanded
    /// or collapsed to. </param>
    public static void ExpandRecursively(this ItemsControl itemsControl, bool expand, int levelDepth)
    {
        // decrease level depth for next recursive call only if levelDepth != int.MaxValue
        int depth = levelDepth == int.MaxValue ? levelDepth : levelDepth - 1;
 
        // expand the item
        TreeViewItem treeViewItem = itemsControl as TreeViewItem;
        if (treeViewItem != null)
            treeViewItem.IsExpanded = expand || levelDepth >= 0; // expand, or keep expanded when levelDepth >= 0
 
        // continue if levelDepth is still bigger than 0, or if subitems need to be collapsed
        if (levelDepth > 0 || !expand)
        {
            // get container generator of itemsControl
            ItemContainerGenerator itemContainerGenerator = itemsControl.ItemContainerGenerator;
 
            // if containers have already been generated, the subItems can be expanded/collapsed
            if (itemContainerGenerator.Status == GeneratorStatus.ContainersGenerated)
            {
                for (int i = itemsControl.Items.Count - 1; i >= 0; --i)
                {
                    ItemsControl childControl = itemContainerGenerator.ContainerFromIndex(i) as ItemsControl;
                    if (childControl != null)
                        childControl.ExpandRecursively(expand, depth);
                }
            }
            // otherwise, we have to wait for the containers to be generated. attach event to listen for status
            else
            {
                EventHandler handler = null; // store in variable, so the handler can be detached
                handler = new EventHandler((s, e) =>
                {
                    if (itemContainerGenerator.Status == GeneratorStatus.ContainersGenerated)
                    {
                        for (int i = itemsControl.Items.Count - 1; i >= 0; --i)
                        {
                            ItemsControl childControl = itemContainerGenerator.ContainerFromIndex(i) as ItemsControl;
                            if (childControl != null)
                                childControl.ExpandRecursively(expand, depth);
                            itemContainerGenerator.StatusChanged -= handler; // detach
                        }
                    }
                });
                itemContainerGenerator.StatusChanged += handler; // attach
            }
        }
    }
}
 

Shrink database (SQL Studio 2008)

Database Properties > Options

• Recovery model: Simple
• Auto Shrink: True

Database Tasks > Shrink

SQL: transfer record from one database to another

        /* The following snippet will copy the complete record with Id = 9 from 
        [databaseName1].[tableName] to [databaseName2].[tableName]*/

        INSERT INTO databaseName1.dbo.tableName 
        SELECT * FROM databaseName2.dbo.tableName 
        WHERE tableName.Id = 9

Fill Background of a Control with Gradient

        /// <summary>
        /// Paints a gradient to the Control's background
        /// </summary>
        /// <param name="ctrl">Control that needs the brush up</param>
        /// <param name="color1">e.g. Color.FromArgb(120, 180, 255), or Color.Yellow</param>
        /// <param name="color2"></param>
        /// <param name="angle">0: horizontal, 45: top-left to bottom-right, etc.</param>
        private void PaintGradientBackground(Control ctrl, Color color1, Color color2, float angle)
        {
            Rectangle rect = new Rectangle(ctrl.Location, ctrl.Size);
 
            System.Drawing.Drawing2D.LinearGradientBrush gradBrush =
                new System.Drawing.Drawing2D.LinearGradientBrush(rect, color1, color2, angle);
 
            Bitmap bmp = new Bitmap(rect.Width, rect.Height);
 
            Graphics g = Graphics.FromImage(bmp);
            g.FillRectangle(gradBrush, rect);
 
            ctrl.BackgroundImage = bmp;
            ctrl.BackgroundImageLayout = ImageLayout.Stretch;
        }

Adding Text with different color styles in RichTextBox

        
        /// <summary>
        /// Writing to a RichTextBox in different colors should be easy enough. The intiuitional way would be:
        /// richTextBox1.Text += someText;
        /// richTextBox1.Select(richTextBox1.Find(someText), someText.Length);
        /// richTextBox1.SelectionColor = Color.Blue;
        /// Which works but gets messed up when other text is added to the RichTextBox.
        /// Adding SelectedText instead of just Text does the trick:
        /// </summary>
        foreach (string ws in WorksheetsRequired)
        {
            if (this.Worksheets.ContainsKey(ws))
            {
                string ok = "Worksheet " + ws + " found." + Environment.NewLine;
                output.SelectionColor = Color.Green;
                output.SelectedText += ok;
            }
 
            else
            {
                string error = "Worksheet " + ws + " could not be found." + Environment.NewLine;
                output.SelectionColor = Color.Red;
                output.SelectedText += error;
            }

            // scroll to bottom of rtb
            output.SelectionStart = this.richTextBox1.Text.Length;
            output.ScrollToCaret();
        }

datatable to combobox

        ''' <summary>
        ''' Binds class names and captions to combobox
        ''' </summary>
        ''' <remarks>The order (DataSource after Diplay- and ValueMember) is important.
        ''' Changing this will put a DataRow into cbx.SelectedValue instead of a string.</remarks>
        Private Sub FillSourceClassComboBox()
 
            Dim dt As New DataTable()
            dt.Columns.Add(DC_CLASSCAPTION, System.Type.GetType("System.String"))
            dt.Columns.Add(DC_CLASSNAME, System.Type.GetType("System.String"))
 
            Dim classes() As String = Me.GetAgent.GetClassNames()
 
            For Each cls As String In classes
                If Not IsNothing(cls) Then
                    Dim dr As DataRow = dt.NewRow()
                    dr(DC_CLASSCAPTION) = Me.GetAgent.EvidenceClass(cls).Caption
                    dr(DC_CLASSNAME) = cls
                    dt.Rows.Add(dr)
                End If
            Next
 
            Dim dv As DataView = dt.DefaultView
            dv.Sort = DC_CLASSCAPTION
            cbxSourceClass.DisplayMember = DC_CLASSCAPTION
            cbxSourceClass.ValueMember = DC_CLASSNAME
            cbxSourceClass.DataSource = dv
 
            ' add handler only now, so method is not executed when binding datasource
            AddHandler cbxSourceClass.SelectedIndexChanged, AddressOf cbxSourceClass_SelectedIndexChanged
 
            cbxSourceClass.SelectedValue = Me.CurrentObject.AttributeValue(ATTR_SOURCECLASS)
 
        End Sub