在每行中绘制矩形，直到Canvas中没有空格 [英] Draw rectangles in each row until no space in Canvas

问题描述

你好专家



我正在研究WPF windows应用程序，我试图通过vb.net创建Rectangle



我能够只做一行。

我需要在每一行重复此操作，直到画布中没有位置。



这是我的XAML

Hello Experts

I am working on WPF windows application where I am trying to create Rectangle through vb.net

I am able to do it for just one row.
I would need to repeat this on Each row until there is no place in the Canvas.

Here is my XAML

<Grid>
            <ScrollViewer CanContentScroll="True" VerticalScrollBarVisibility="Visible" HorizontalScrollBarVisibility="visible">
                <Canvas Height="700" Width="1200" Name="front_canvas" Grid.Row="3" Grid.Column="2" >
                    <Canvas.RenderTransform>
                        <ScaleTransform ScaleX="1" ScaleY="1" />
                        
                    </Canvas.RenderTransform>

</Canvas>
</scrollviewer>
</Grid>

这是我的Vb.net

Here is my Vb.net

Private _top As Double = 0
Protected Sub DrawRect()
     
            'init rectangles
            'front_canvas.Width - 1 Step 1100
                               For i As Integer = 1 To front_canvas.Width - 1 Step 100
                        Dim rect As New Rectangle()
                        rect.StrokeThickness = 1
                        rect.Stroke = System.Windows.Media.Brushes.Black
                        rect.Width = 50
                        rect.Height = 50
                        rect.Name = "box" + i.ToString()
                        If Not i / 2 = 0 Then
                            Canvas.SetLeft(rect, i)
                     Canvas.SetTop(rect, Top)
                    _top += rect.Height
                        End If

                        _rectangles.Add(rect)
                    Next
                    For Each rect In _rectangles
                        front_canvas.Children.Add(rect)
                    Next
              End Sub 

我正在寻找类似下面的东西

I am looking for something like below

o o o o 
o o o o 
o o o o 

or 

oo oo oo oo
oo oo oo oo 
oo oo oo oo

上面的所有o都是我的情况下的矩形。



使用当前代码我的应用程序显示如下

All the o's in the above are Rectangles in my case.

With the current code my application shows like below

o o o o o o o o 

感谢一些帮助

Would appreciate some help in this

推荐答案

问题似乎与你的表述一样明显。你提到只有一行，并且会立即尝试查看你将矩形移动到哪一行。很明显，因为你使用 Canvas.SetLeft ，但从不 Canvas.SetTop 。显然，对于每一行，您应该使用不同的顶部坐标。将调用添加到 Canvas.SetTop ：

Canvas.SetTop方法（System.Windows.Controls） [ ^ ]。



这就是全部。



现在，请看我对这个问题的评论。除此之外：如果你只是开始编写整洁的代码，很多你的小错误就会出现。看，现在你的代码基于立即常量，如1110,10,5,100和50.显然它们是相互关联的。你不应该硬编码，比方说，移位，因为它们是根据矩形的数量和大小计算出来的。你应该计算一切。大多数直接常量应该成为具有计算值的变量，其他应该变为显式声明的常量，从不重复或方法参数。只有这样你才能维护你的代码并减少错误。

-SA

The problem seems to be as obvious as your formulation. You mention "just one row" and immediately one would try to see where you shift the rectangle for a row. And it becomes obvious, because you use Canvas.SetLeft, but never Canvas.SetTop. Apparently, for every row you should use different top coordinate. Add the call to Canvas.SetTop:
Canvas.SetTop Method (System.Windows.Controls)[^].

That's all.

Now, please see my comment to the question. In addition to that: many your minor bugs such as this one will go if you simply start to write neat code. Look, right now your code is based on immediate constants like 1110, 10, 5, 100 and 50. It's apparent that they are interrelated. You should not hard-code, say, shifts, because they are calculated out of number of rectangles and the size. You should calculate everything. Most of your immediate constants should become variables with calculated values, other should become either explicitly declared constants, never repeated, or method parameters. Only then you will be able to maintain your code and will have less bugs.

—SA

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