如何得到一个ListView项用户点击与listview.GetItemAtPosition（e.Position）的数据？ [英] How to get the data of a ListView item the user has clicked on with listview.GetItemAtPosition(e.Position)?

问题描述

在Xamarin.Android应用程序，我有我以前填充一个ListView。
在listview_ItemClick事件处理程序，它正确触发，我想找回的点击列表视图项意见的文本，以显示其在AlertDialog一些信息。

我的代码无法正常工作，因为所有我能得到一个的java.lang.Object（LVITEM），我不知道如何从中提取我需要的意见。

 私人无效lv_ItemClick（对象发件人，AdapterView.ItemClickEventArgs E）{
 
 LVITEM = lv.GetItemAtPosition（e.Position）; 
 // LVITEM是的java.lang.Object 
 
 Toast.MakeText（这一点，+你点击+ LVITEM，ToastLength.Long）.Show（）; 
} 
  

如果我运行它这样的，吐司打印：

您点击System.Collections.Generic.Dictionary'2 [System.String，
System.String]

< /块引用>

请注意，每个ListView的行由两个TextViews，我通过传递列表与LT填充的ListView;字典<字符串，字符串>> 到ListView适配器构造

要说得简单：

LISTVIEW

| textView1 | textView2 | --->项目1

| textView1 | textView2 | --->项目2

如果用户点击的ListView ITEM2我需要检索textView1.Text或textView2.Text 2项。

我也想过这样做的：

  FindViewById< TextView的>（resultsListView.GetItemIdAtPosition（e.Position ）; 
  

但适配器GetItemIdAtPosition返回，而不是长期的INT，所以我不知道这是同一种标识的。

下面是不是工作压力太大（我认为这是同一个 lv.GetItemAtPosition（e.position）的：

  lv.Adapter.GetItem（e.Position）; 
  

解决方案

也许有这样的事？

  = LVITEM lv.GetItemAtPosition（e.Position）; 
  

虽然林不知道它会与Java对象的工作，也许尝试施放此对象与此线程的帮助？的 https://forums.xamarin.com/discussion/7894/how-to-convert-a-type-to-java-lang-object

转换的java.lang.Object 为 C＃

 公共静态类ObjectTypeHelper 
 {
公共静态牛逼演员LT; T>（此的java.lang.Object OBJ）其中T：类
 {
变种的PropertyInfo = obj.GetType（）的getProperty（实例）。 
返回的PropertyInfo == NULL？空：propertyInfo.GetValue（OBJ，NULL）为T; 
} 
} 
  

in a Xamarin.Android app, I have a ListView which I previously populated. In the listview_ItemClick event handler, which correctly fires, I would like to retrieve the text of the clicked listview-item views, in order to show some info about it in a AlertDialog.

My code is not working because all I can get to is a Java.Lang.Object (lvItem) and I don't know how to extract from it the Views I need.

private void lv_ItemClick(object sender, AdapterView.ItemClickEventArgs e) {

    lvItem = lv.GetItemAtPosition(e.Position);
    // lvItem is a Java.Lang.Object

    Toast.MakeText(this,  + "you clicked" + lvItem, ToastLength.Long).Show();
}

If I run it like this, the Toast prints:

you clicked System.Collections.Generic.Dictionary'2[System.String, System.String]

Note that each ListView row is made up of two TextViews, and I populate the ListView by passing a List<Dictionary<string,string>> to the ListView Adapter constructor.

To put it simpler:

LISTVIEW

| textView1 | textView2 | ---> item 1

| textView1 | textView2 | ---> item 2

If user clicks on item2 of ListView I need to retrieve textView1.Text or textView2.Text of item 2.

I also thought about doing:

FindViewById<TextView>(resultsListView.GetItemIdAtPosition(e.Position);

but the Adapter GetItemIdAtPosition returns a long instead of a int, and so I am not sure that it's the same kind of Id.

The following is not working too (I think it's the same of lv.GetItemAtPosition(e.position):

lv.Adapter.GetItem(e.Position);

解决方案

Maybe with something like this?

lvItem = lv.GetItemAtPosition(e.Position);

Although im not sure it will work with java objects, maybe try to cast this object with the help of this thread? https://forums.xamarin.com/discussion/7894/how-to-convert-a-type-to-java-lang-object

Converting Java.Lang.Object to C#:

public static class ObjectTypeHelper
{
    public static T Cast<T>(this Java.Lang.Object obj) where T : class
    {
        var propertyInfo = obj.GetType().GetProperty("Instance");
        return propertyInfo == null ? null : propertyInfo.GetValue(obj, null) as T;
    }
}

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