Grid 行和列

<Grid>
            <Grid.ColumnDefinitions>
                <ColumnDefinition></ColumnDefinition>
                <ColumnDefinition></ColumnDefinition>
                <ColumnDefinition></ColumnDefinition>

            </Grid.ColumnDefinitions>
            <Grid.RowDefinitions>
                <RowDefinition></RowDefinition>
                <RowDefinition></RowDefinition>
                <RowDefinition></RowDefinition>
                <RowDefinition></RowDefinition>
            </Grid.RowDefinitions>
        </Grid>

<Grid.ColumnDefinitions>列定义

<Grid.RowDefinitions>行定义

<ColumnDefinition Width="40"></ColumnDefinition> 列有宽度定义

<RowDefinition Height="20"></RowDefinition>行有高度定义