我试图创建一个简单的3列6行的网格。我已经定义了行和列的高度和宽度。但是，整个网格总是从屏幕的中间开始。整个屏幕的左手边是空的。

<Grid>
            <Grid.RowDefinitions>
                <RowDefinition Height="60"/>
                <RowDefinition Height="60"/>
                <RowDefinition Height="60"/>
                <RowDefinition Height="60"/>
                <RowDefinition Height="60"/>
                <RowDefinition Height="60"/>
            </Grid.RowDefinitions>
            <Grid.ColumnDefinitions>
                <ColumnDefinition Width="120"/>
                <ColumnDefinition Width="Auto"/>
                <ColumnDefinition Width="60"/>
            </Grid.ColumnDefinitions>
            <Label Text="Height: " FontSize="Medium" Grid.Row="1" Grid.Column="1" BackgroundColor="Blue"/>
            <Entry x:Name="heightEntry" FontSize="Medium" Grid.Row="1" Grid.Column="2" BackgroundColor="Blue"/>
            <Label Text=" cm" FontSize="Medium" Grid.Row="1" Grid.Column="3" BackgroundColor="Blue"/>
            <Label Text="Width: " FontSize="Medium" Grid.Row="2" Grid.Column="1" BackgroundColor="Blue"/>
            <Entry x:Name="widthEntry" FontSize="Medium" Grid.Row="2" Grid.Column="2" BackgroundColor="Blue"/>
            <Label Text=" cm" FontSize="Medium" Grid.Row="2" Grid.Column="3" BackgroundColor="Blue"/>
            <Label Text="Depth: " FontSize="Medium" Grid.Row="3" Grid.Column="1" BackgroundColor="Blue"/>
            <Entry x:Name="depthEntry" FontSize="Medium" Grid.Row="3" Grid.Column="2" BackgroundColor="Blue"/>
            <Label Text=" cm" FontSize="Medium" Grid.Row="3" Grid.Column="3" BackgroundColor="Blue"/>
            <Label Text="Weight (Full): " FontSize="Medium" Grid.Row="4" Grid.Column="1" BackgroundColor="Blue"/>
            <Entry x:Name="weightEntry" FontSize="Medium" Grid.Row="4" Grid.Column="2" BackgroundColor="Blue"/>
            <Label Text=" g" FontSize="Medium" Grid.Row="4" Grid.Column="3" BackgroundColor="Blue"/>
            <Label Text="CaseQty: " FontSize="Medium" Grid.Row="5" Grid.Column="1" BackgroundColor="Blue"/>
            <Entry x:Name="qtyEntry" FontSize="Medium" Grid.Row="5" Grid.Column="2" BackgroundColor="Blue"/>
            <Label Text="Box Count: " FontSize="Medium" Grid.Row="6" Grid.Column="1" BackgroundColor="Blue"/>
            <Entry x:Name="boxEntry" FontSize="Medium" Grid.Row="6" Grid.Column="2" BackgroundColor="Blue"/>
           
        </Grid>

我尝试过更改单个元素的水平选项，网格本身和它嵌入的堆栈布局。没有任何变化。我也尝试过改变宽度本身（列定义）以及标签和条目的WidthRequests。没有任何变化。我不知道我做错了什么。我只想控制每列的宽度并左对齐每一行。这是如何实现的？