public class ListViewDemo extends ListActivity {
//LIST OF ARRAY STRINGS WHICH WILL SERVE AS LIST ITEMS
ArrayList<String> listItems=new ArrayList<String>();
//DEFINING A STRING ADAPTER WHICH WILL HANDLE THE DATA OF THE LISTVIEW
ArrayAdapter<String> adapter;
//RECORDING HOW MANY TIMES THE BUTTON HAS BEEN CLICKED
int clickCounter=0;
@Override
public void onCreate(Bundle icicle) {
super.onCreate(icicle);
setContentView(R.layout.main);
adapter=new ArrayAdapter<String>(this,
android.R.layout.simple_list_item_1,
listItems);
setListAdapter(adapter);
}
//METHOD WHICH WILL HANDLE DYNAMIC INSERTION
public void addItems(View v) {
listItems.add("Clicked : "+clickCounter++);
adapter.notifyDataSetChanged();
}
}
private EditText editTxt;
private Button btn;
private ListView list;
private ArrayAdapter<String> adapter;
private ArrayList<String> arrayList;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
editTxt = (EditText) findViewById(R.id.editText);
btn = (Button) findViewById(R.id.button);
list = (ListView) findViewById(R.id.listView);
arrayList = new ArrayList<String>();
// Adapter: You need three parameters 'the context, id of the layout (it will be where the data is shown),
// and the array that contains the data
adapter = new ArrayAdapter<String>(getApplicationContext(), android.R.layout.simple_spinner_item, arrayList);
// Here, you set the data in your ListView
list.setAdapter(adapter);
btn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
// this line adds the data of your EditText and puts in your array
arrayList.add(editTxt.getText().toString());
// next thing you have to do is check if your adapter has changed
adapter.notifyDataSetChanged();
}
});
}
public class ListViewDemoActivity extends AppCompatActivity {
//LIST OF ARRAY STRINGS WHICH WILL SERVE AS LIST ITEMS
ArrayList<String> listItems=new ArrayList<String>();
//DEFINING A STRING ADAPTER WHICH WILL HANDLE THE DATA OF THE LISTVIEW
ArrayAdapter<String> adapter;
//RECORDING HOW MANY TIMES THE BUTTON HAS BEEN CLICKED
int clickCounter=0;
private ListView mListView;
@Override
public void onCreate(Bundle icicle) {
super.onCreate(icicle);
setContentView(R.layout.activity_list_view_demo);
if (mListView == null) {
mListView = (ListView) findViewById(R.id.listDemo);
}
adapter=new ArrayAdapter<String>(this,
android.R.layout.simple_list_item_1,
listItems);
setListAdapter(adapter);
}
//METHOD WHICH WILL HANDLE DYNAMIC INSERTION
public void addItems(View v) {
listItems.add("Clicked : "+clickCounter++);
adapter.notifyDataSetChanged();
}
protected ListView getListView() {
if (mListView == null) {
mListView = (ListView) findViewById(R.id.listDemo);
}
return mListView;
}
protected void setListAdapter(ListAdapter adapter) {
getListView().setAdapter(adapter);
}
protected ListAdapter getListAdapter() {
ListAdapter adapter = getListView().getAdapter();
if (adapter instanceof HeaderViewListAdapter) {
return ((HeaderViewListAdapter)adapter).getWrappedAdapter();
} else {
return adapter;
}
}
}
5 回答
首先在项目的
res/layout/main.xml
文件夹中创建XML布局:这是一个简单的布局,顶部有一个按钮,底部有一个列表视图 . 请注意
ListView
的id为@android:id/list
,它定义了ListView
可以使用的默认值ListView
.android.R.layout.simple_list_item_1
是Android提供的默认列表项布局,您可以将此库存布局用于非复杂事物 .listItems
是一个List,用于保存ListView中显示的数据 . 所有插入和删除都应在listItems
上完成;listItems
中的更改应反映在视图中 . 这是由ArrayAdapter<String> adapter
处理的,应该通过以下方式通知:adapter.notifyDataSetChanged();
适配器实例化有3个参数:上下文,可能是你的
activity/listactivity
;单个列表项的布局;最后,列表,即列表中显示的实际数据 .代替
你可以直接打电话
首先,您必须在activity_main.xml中添加ListView,EditText和按钮 .
现在,在您的ActivityMain中:
这对我有用,我希望我帮助过你
如果您想在AppCompatActivity而不是ListActivity中使用ListView,您可以执行以下操作(修改@ Shardul的答案):
在你的布局而不是使用
android:id="@android:id/list"
你可以使用android:id="@+id/listDemo"
所以现在你可以在正常的
AppCompatActivity
中使用ListView
.Code for MainActivity.java file.
Code for activity_main.xml layout file.
ScreenShot