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c# - 如何检索元素父容器的属性

问题描述

我在线性布局中有多个卡片视图，每张卡片中有两个复选框。如何获取我的复选框所在的容器（Cardview）的文本属性？

我浏览了 Xamarin.Android 文档，看看是否有办法访问元素的父级或容器。我看到 Xamarin.Forms 有一个 Element 类，可用于访问元素的父级。

我已尝试从 Cardview 捕获文本并将其放入字符串中，这将不起作用，因为文本可能会因检查复选框的 cardview 而异。 

//Here are my initialisers
btnOrder = FindViewById<Button>(Resource.Id.btnOrder);
pancakeTypeSpnr = FindViewById<Spinner>(Resource.Id.pancaketypespnr);
pancakeStyleSpnr = FindViewById<Spinner>(Resource.Id.pancakestylespnr);
pancakeQuantitySpnr = FindViewById<Spinner>(Resource.Id.pancakequantityspnr);

cardSugar = FindViewById<CardView>(Resource.Id.cardSugar);
cardSugar.Click += CardSugar_Click;

cardLemonJuice = FindViewById<CardView>(Resource.Id.cardLemonJuice);
cardLemonJuice.Click += CardLemonJuice_Click;

cardGoldenSyrup = FindViewById<CardView>(Resource.Id.cardGoldenSyrup);
cardGoldenSyrup.Click += CardGoldenSyrup_Click;

cardMarmite = FindViewById<CardView>(Resource.Id.cardMarmite);
cardMarmite.Click += CardMarmite_Click;

cardStrawberries = FindViewById<CardView>(Resource.Id.cardStrawberries);
cardStrawberries.Click += CardStrawberries_Click;

cardChocolateSpread = FindViewById<CardView>(Resource.Id.cardChocolateSpread);
cardChocolateSpread.Click += CardChocolateSpread_Click;

cardBlueberries = FindViewById<CardView>(Resource.Id.cardBlueberries);
cardBlueberries.Click += CardBlueberries_Click;

//Topping checkbox reference
checkToppingSugar = FindViewById<CheckBox>(Resource.Id.checkToppingSugar);
checkToppingLemonJuice = FindViewById<CheckBox>(Resource.Id.checkToppingLemonJuice);
checkToppingGoldenSyrup = FindViewById<CheckBox>(Resource.Id.checkToppingGoldenSyrup);
checkToppingMarmite = FindViewById<CheckBox>(Resource.Id.checkToppingMarmite);
checkToppingStrawberries = FindViewById<CheckBox>(Resource.Id.checkToppingStrawberries);
checkToppingChocolateSpread = FindViewById<CheckBox>(Resource.Id.checkToppingChocolateSpread);
checkToppingBlueberries = FindViewById<CheckBox>(Resource.Id.checkToppingBlueberries);

//Filling checkbox reference
checkFillingSugar = FindViewById<CheckBox>(Resource.Id.checkFillingSugar);
checkFillingLemonJuice = FindViewById<CheckBox>(Resource.Id.checkFillingLemonJuice);
checkFillingGoldenSyrup = FindViewById<CheckBox>(Resource.Id.checkFillingGoldenSyrup);
checkFillingMarmite = FindViewById<CheckBox>(Resource.Id.checkFillingMarmite);
checkFillingStrawberries = FindViewById<CheckBox>(Resource.Id.checkFillingStrawberries);
checkFillingChocolateSpread = FindViewById<CheckBox>(Resource.Id.checkFillingChocolateSpread);
checkFillingBlueberries = FindViewById<CheckBox>(Resource.Id.checkFillingBlueberries);

The following is my Order button code

 //Order button... Completes initial check to see if compulsary boxes have been checked, then compiles order
private void BtnOrder_Click(object sender, EventArgs e)
{
   if (pancakeTypeSpnr.SelectedItemPosition == 0)
{
   Toast.MakeText(this, "You must select a pancake type!", 
   ToastLength.Short).Show();
}
   else if (pancakeStyleSpnr.SelectedItemPosition == 0)
{
   Toast.MakeText(this, "You must select a pancake style!", 
   ToastLength.Short).Show();
}
   else if (pancakeQuantitySpnr.SelectedItemPosition == 0)
{
   Toast.MakeText(this, "You must order at least one pancake", 
   ToastLength.Short).Show();
}
   else
{

/*This section takes all the checkboxes and checks them to see if they are checked. If they are, they are put into an array of checked boxes*/

CheckBox[] checkBoxesToppings = { checkToppingSugar, checkToppingLemonJuice, checkToppingGoldenSyrup, checkToppingMarmite, checkToppingStrawberries, checkToppingChocolateSpread, checkToppingBlueberries };
toppingsReturned = CheckDetails(checkBoxesToppings);
string toppings = "";
foreach (CheckBox toppingbox in toppingsReturned)
   {
    toppings = toppings + toppingbox.Tag.ToString() + "\n";
   }

CheckBox[] checkBoxesFillings = { checkFillingSugar, checkFillingLemonJuice, checkFillingGoldenSyrup, checkFillingMarmite, checkFillingStrawberries, checkFillingChocolateSpread, checkFillingBlueberries };
fillingsReturned = CheckDetails(checkBoxesFillings);
string fillings = "";
foreach (CheckBox fillingbox in fillingsReturned)
   {
    fillings = fillings + fillingbox.Text.ToString() + "\n";
   }

//This toast is for testing purposes only
string order = "The following has been added to your order:\n" +
pancakeQuantitySpnr.SelectedItem + "\n" +
"Pancake type: " + pancakeTypeSpnr.SelectedItem + "\n" +
"Pancake style: " + pancakeStyleSpnr.SelectedItem + "\n" +
"Fillings: " + "\n" + fillings +
"Toppings: " + "\n" + toppings;
Toast.MakeText(this, order, ToastLength.Long).Show();
}
}

private CheckBox[] CheckDetails(CheckBox[] details)
{
var checkedCheckboxes = new List<CheckBox>();
foreach (CheckBox cb in details)
{
if (cb.Checked == true)
{
checkedCheckboxes.Add(cb);
}
else continue;
}
CheckBox[] ticked = checkedCheckboxes.ToArray();
return ticked;
}

单击订单按钮时​​，我希望 BtnOrder_Click 方法代码能够判断从哪张卡片（即糖、巧克力酱）中单击了顶部/填充复选框。

标签： c#xamarin.androidattributes

解决方案

我已经尝试从 Cardview 捕获文本并将其放入字符串中，这不起作用，因为文本可能会因检查复选框的 cardview 而异。

我可以得到如下cardview的文本。It works well when the checkbox is selected and the text changed.

1.根据你的TextViews的id获取文本

var str = textView.Text;

您提供的代码没有显示如何更改文本，我使用下面的代码进行测试。文本视图在 cardSugar Cardview 中。

  var textView = FindViewById<TextView>(Resource.Id.textView);

        var checkToppingSugar = FindViewById<CheckBox>(Resource.Id.checkToppingSugar);
        checkToppingSugar.Click += (o, e) =>
        {
            if (checkToppingSugar.Checked)
            {
                Toast.MakeText(this, "Selected", ToastLength.Short).Show();
                textView.Text = "textView Topping Selected";
            }
            else
            {
                Toast.MakeText(this, "Not selected", ToastLength.Short).Show();
                textView.Text = "textView Topping Not selected";
            }

        };

2.通过foreach线性布局中的所有元素获取文本。它需要与您定义的布局相匹配。您可以参考我项目中的布局。我在输出窗口上输出结果。

  var linearLayout = FindViewById<LinearLayout>(Resource.Id.linearlayout_view);
            for (int i = 0; i < linearLayout.ChildCount; i++)
            {
                View child = linearLayout.GetChildAt(i);
                if (child.GetType() == typeof(CardView))
                {
                    var viewGroup = ((ViewGroup)child).GetChildAt(0);

                    for (int j = 0; j < ((ViewGroup)viewGroup).ChildCount; j++)
                    {
                        var viewGroup2 = ((ViewGroup)viewGroup).GetChildAt(j);
                        if (viewGroup2.GetType() == typeof(TextView))
                        {
                            System.Diagnostics.Debug.WriteLine(viewGroup2.GetType().ToString() + ": " + ((TextView)viewGroup2).Text);
                        }
                    }
                }

            }

单击订单按钮时​​，我希望 BtnOrder_Click 方法代码能够判断从哪张卡片（即糖、巧克力酱）中单击了顶部/填充复选框。

我建议您将复选框放在 Cardview 中，以便我们可以连接它们。当您选中下面的复选框时，您可以获得卡片视图。

for (int i = 0; i < linearLayout.ChildCount; i++)
            {
                View child = linearLayout.GetChildAt(i);
                if (child.GetType() == typeof(CardView))
                {
                    var viewGroup = ((ViewGroup)child).GetChildAt(0);

                    for (int j = 0; j < ((ViewGroup)viewGroup).ChildCount; j++)
                    {
                        var viewGroup2 = ((ViewGroup)viewGroup).GetChildAt(j);
                        if (viewGroup2.GetType() == typeof(CheckBox))
                        {
                            if (((CheckBox)viewGroup2).Checked)
                            {
                                System.Diagnostics.Debug.WriteLine(((CardView)child));
                            }                               
                        }
                    }
                }

            }

结果：最后一次，carduger 输出两次，因为我检查了 carduger 的两个复选框（Topping 和 Filling）。 在此处输入图像描述

您可以从 GitHub 的 Cardview/AndroidDemo 文件夹下载以供参考。 https://github.com/WendyZang/Test.git

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