When application is maximized, Can't click certain textboxes or comboboxes

Question

When i maximize my application and try to set focus or click into certain textboxes or comboboxes I am unable to. After running my mouse over these objects many times I can sometimes find the one perfect spot that will let me click. Any Idea what may be causing this or how to fix it.

XAML Snipit:

Window x:Class="qaTrackingDatabase.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="QA Tracking DB Update Tool" Height="715.963" MinHeight="715.983" Width="868.283" MinWidth="878.283" Icon="rm12icon.ico" VerticalAlignment="Top">
<Grid Margin="0,0,-8,3">
    <Grid.Background>
        <LinearGradientBrush EndPoint="0.5,1" StartPoint="0.5,0">
            <GradientStop Color="#FFDFEDF7" Offset="0"/>
            <GradientStop Color="#FFDFECF7" Offset="1"/>
        </LinearGradientBrush>
    </Grid.Background>

    <TabControl  Name="myTabControl" Margin="0" SelectionChanged="TabControl_SelectionChanged" Background="#FFDFECF7">
        <TabItem x:Name="Branch" Header="Branch" MinWidth="170" MinHeight="25">
            <Border BorderBrush="Black" BorderThickness="1" MaxHeight="238" Margin="10" VerticalAlignment="Top">
                <Grid>
                    <RadioButton Name="Add" Content="Add" Margin="25,28,0,150" Checked="Branch_RadioBtns_Checked" HorizontalAlignment="Left" Width="619"/>
                    <RadioButton Name="Delete" Content="Delete" Margin="25,99,202,84"  Checked="Branch_RadioBtns_Checked" />
                    <TextBox Name="Add_Name_txtBox" IsEnabled="{Binding ElementName=Add, Path=IsChecked}" Height="25" TextWrapping="Wrap" Text="Enter Name" Width="230" Margin="352,53,264,0" SpellCheck.IsEnabled="True" Background="White" VerticalAlignment="Top" HorizontalAlignment="Left"/>
                    <TextBlock TextDecorations="Underline" FontWeight="Bold" FontFamily="Levenim MT" Margin="250,57,490,158"> Branch Name:</TextBlock>
                    <ComboBox Name="Dproduct_Combo" IsEnabled="{Binding ElementName=Delete, Path=IsChecked}" Text="Select" HorizontalAlignment="Left" Height="25" Margin="111,120,0,0" VerticalAlignment="Top" Width="119" IsReadOnly="True" SelectionChanged="Get_Dproduct_Branch"/>
                    <TextBlock TextDecorations="Underline" FontWeight="Bold" FontFamily="Levenim MT" Margin="41,123,740,92"> Product:</TextBlock>
                    <ComboBox Name="Aproduct_Combo" IsEnabled="{Binding ElementName=Add, Path=IsChecked}" Text="Select" HorizontalAlignment="Left" Height="25" Margin="111,53,0,0" VerticalAlignment="Top" Width="119"/>
                    <TextBlock TextDecorations="Underline" FontWeight="Bold" FontFamily="Levenim MT" Margin="41,57,740,150"> Product:</TextBlock>
                    <TextBlock TextDecorations="Underline" FontWeight="Bold" FontFamily="Levenim MT" Margin="250,123,490,91"> Select Branch:</TextBlock>
                    <ComboBox Name="Dbranch_Combo" IsEnabled="{Binding ElementName=Delete, Path=IsChecked}" HorizontalAlignment="Left" Height="25" VerticalAlignment="Top" Width="119" IsReadOnly="True" Margin="351,119,0,0"/>
                    <Button Content="Commit&#xD;&#xA;Changes" FontFamily="Levenim MT" FontWeight="Bold" FontSize="16" Click="Branch_Commit_Changes" Margin="637,177,10,10" MaxHeight="49" MaxWidth="189"  MinHeight="49" MinWidth="189" HorizontalAlignment="Left"/>
                </Grid>
            </Border>
        </TabItem>

Answer 1

There's something very strange going on with your Margin/Height/Width values. I'd strongly suggest that you start using grid rows and columns. In the long run you'll find that everything resizes and works much better in XAML when you do.

Here's an update the tab control in your window.

    <TabControl  Name="myTabControl" Margin="0" SelectionChanged="TabControl_SelectionChanged" Background="#FFDFECF7">
        <TabItem x:Name="Branch" Header="Branch" MinWidth="170" MinHeight="25">
            <Border BorderBrush="Black" BorderThickness="1" Margin="10" VerticalAlignment="Top">
                <Grid>
                    <Grid.RowDefinitions>
                        <RowDefinition Height="Auto" />
                        <RowDefinition Height="Auto" />
                        <RowDefinition Height="Auto" />
                        <RowDefinition Height="Auto" />
                        <RowDefinition Height="Auto" />
                    </Grid.RowDefinitions>
                    <Grid.ColumnDefinitions>
                        <ColumnDefinition Width="Auto" />
                        <ColumnDefinition Width="Auto" />
                        <ColumnDefinition Width="Auto" />
                        <ColumnDefinition Width="Auto" />
                        <ColumnDefinition Width="Auto" />
                    </Grid.ColumnDefinitions>
                    <RadioButton Grid.Row="0"  Margin="5" Name="Add" Content="Add" />
                    <TextBlock Grid.Row="1" Grid.Column="0" Margin="5" TextDecorations="Underline" FontWeight="Bold" FontFamily="Levenim MT" > Product:</TextBlock>
                    <ComboBox Grid.Row="1" Grid.Column="1" Margin="5" Name="Aproduct_Combo" IsEnabled="{Binding ElementName=Add, Path=IsChecked}" Text="Select" Width="119"/>
                    <TextBlock Grid.Row="1" Grid.Column="2" Margin="5" TextDecorations="Underline" FontWeight="Bold" FontFamily="Levenim MT" > Branch Name:</TextBlock>
                    <TextBox Grid.Row="1" Grid.Column="3" Margin="5" Name="Add_Name_txtBox" IsEnabled="{Binding ElementName=Add, Path=IsChecked}" TextWrapping="Wrap" Text="Enter Name" Width="230" SpellCheck.IsEnabled="True" Background="White" />
                    <RadioButton Grid.Row="2" Margin="5" Name="Delete" Content="Delete"  />
                    <TextBlock Grid.Row="3" Grid.Column="0" Margin="5" TextDecorations="Underline" FontWeight="Bold" FontFamily="Levenim MT" > Product:</TextBlock>
                    <ComboBox Grid.Row="3" Grid.Column="1" Margin="5" Name="Dproduct_Combo" IsEnabled="{Binding ElementName=Delete, Path=IsChecked}" Text="Select" Width="119" IsReadOnly="True" />
                    <TextBlock Grid.Row="3" Grid.Column="2" Margin="5" TextDecorations="Underline" FontWeight="Bold" FontFamily="Levenim MT" > Select Branch:</TextBlock>
                    <ComboBox Grid.Row="3" Grid.Column="3" Margin="5" Name="Dbranch_Combo" IsEnabled="{Binding ElementName=Delete, Path=IsChecked}" IsReadOnly="True" />
                    <Button Grid.Row="4" Grid.Column="4" Margin="5" Content="Commit&#xD;&#xA;Changes" FontFamily="Levenim MT" FontWeight="Bold" FontSize="16" />
                </Grid>
            </Border>
        </TabItem>
    </TabControl>