WP布局内容多后无法显示,拖动无效果

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<Grid x:Name="ContentPanel" Height="1000" Grid.Row="100" Margin="12,0,12,0">
                <Grid.RowDefinitions>
                    <RowDefinition Height="*"/>
                    <RowDefinition Height="*"/>
                    <RowDefinition Height="*"/>
                        <RowDefinition Height="*"/>
                        <RowDefinition Height="*"/>
                        <RowDefinition Height="*"/>
                        <RowDefinition Height="*"/>
                        <RowDefinition Height="*"/>
                        <RowDefinition Height="*"/>
                        <RowDefinition Height="*"/>
                        <RowDefinition Height="*"/>
                        <RowDefinition Height="*"/>
                        <RowDefinition Height="*"/>
                        <RowDefinition Height="*"/>
                    </Grid.RowDefinitions>

                <Grid.ColumnDefinitions>
                    <ColumnDefinition Width="*"/>
                    <ColumnDefinition Width="*"/>
                </Grid.ColumnDefinitions>

                <Button Content="按钮1"/>
                <Button Content="按钮2" Grid.Row="1" Grid.Column="0" Background="Blue"/>
                <Button Content="按钮3" Grid.Column="1" Grid.RowSpan="2" Background="Gray"/>
                <Button Content="按钮4" Grid.Row="2" Grid.ColumnSpan="2" Background="Red"/>
                <Button Content="按钮5" Grid.Row="3" Grid.ColumnSpan="2" Background="Red"/>
                <Button Content="按钮6" Grid.Row="4" Grid.ColumnSpan="2" Background="Red"/>
                    <Button Content="按钮7" Grid.Row="5" Grid.ColumnSpan="2" Background="Red"/>
                    <Button Content="按钮8" Grid.Row="6" Grid.ColumnSpan="2" Background="Red"/>
                    <Button Content="按钮9" Grid.Row="7" Grid.ColumnSpan="2" Background="Red"/>
                    <Button Content="按钮7" Grid.Row="8" Grid.ColumnSpan="2" Background="Red"/>
                    <Button Content="按钮8" Grid.Row="9" Grid.ColumnSpan="2" Background="Red"/>
                    <Button Content="按钮9" Grid.Row="10" Grid.ColumnSpan="2" Background="Red"/>
                    <Button Content="按钮7" Grid.Row="11" Grid.ColumnSpan="2" Background="Red"/>
                    <Button Content="按钮8" Grid.Row="12" Grid.ColumnSpan="2" Background="Red"/>
            <Button Content="按钮9" Grid.Row="13" Grid.ColumnSpan="2" Background="Red"/>
        </Grid>

拖动屏幕后没反映,下面的内容无法显示