Question

在Xamarin

我想在ListVIew中添加一个简单的TextView，但不确定代码是否正确。

这是我目前的代码：

protected override void OnCreate (Bundle bundle)
{
    base.OnCreate (bundle);

    SetContentView (Resource.Layout.Main);

    ListView listView = new ListView(this.ApplicationContext);
    TextView textView = new TextView (this.ApplicationContext);
    textView.Text = "Example text";
    View view = new View (this.ApplicationContext);
}

我可以请一些帮助吗？

修改

这是我的代码：

protected override void OnCreate (Bundle bundle)
{
    base.OnCreate (bundle);

    ListView lst = (ListView) FindViewById(Resource.Id.listView);

    // create the ArrayList to store the titles of nodes
    List<String> listItems = new List<String>();
    listItems.Add ("Test 1");
    listItems.Add ("Test 2");

    ArrayAdapter ad = new ArrayAdapter(this.ApplicationContext, Resource.Layout.simple_list_item_1, listItems);

    // give adapter to ListView UI element to render
    lst.SetAdapter(ad);

    }

我收到此错误：

UNHANDLED EXCEPTION: System.NullReferenceException: Object reference not set to an instance of an object

我可以帮忙看一下这段代码吗？

提前致谢

Answer 1

如果它是一个简单的textView List，那么使用它：

ListView lst = (ListView) findViewById(R.id.listView);

        // create the ArrayList to store the titles of nodes
        ArrayList<String> listItems = new ArrayList<String>();

然后在ArrayList listItems中添加所有文本然后使用以下方法

ArrayAdapter ad = new ArrayAdapter(ListActivity.this,
                android.R.layout.simple_list_item_1, listItems);

        // give adapter to ListView UI element to render
        lst.setAdapter(ad);

XML文件：

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
  xmlns:tools="http://schemas.android.com/tools"
  android:layout_width="match_parent"
  android:layout_height="match_parent"
  tools:context=".DisplayMessageActivity"
  android:orientation="vertical">

<ListView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/listView"
        android:smoothScrollbar="true"
        android:fastScrollAlwaysVisible="false"
        android:layout_centerHorizontal="true"
        android:layout_gravity="center"/>

 </LinearLayout>

Answer 2

检查this链接。您可以根据自己的要求使用它 type2

Answer 3

如果您只想在ListView中显示一些字符串：

声明以下变量：

private ArrayList<String> _listEntrys = new ArrayList<String>();    // String-ArrayList for storing the itmes that should be shown in the list
private ArrayAdapter<String> _arrayAdapter;                     // Arrayadapter to fill your list

你的OnCreate应该是这样的：

protected void onCreate(Bundle savedInstanceState)
{
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);


    // Create ListView
    ListView listView = new ListView(this.ApplicationContext);

    // Set Array-Adapter
    _arrayAdapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, _listEntrys);
    listview.setAdapter(m_ArrayAdapter);
    listview.setOnItemClickListener(this);

    // Add here your desired List-Items
    _listEntrys.add("your string");

    _arrayAdapter.notifyDataSetChanged();   // Call this everytime you change the values in the ArrayList to refresh the view

}

将TextView添加到ListView

3 个答案: