Question

我是Android开发的新手，并且仍在学习一些技能，但是在使用ListView和ArrayAdapter删除项目时遇到了问题。我一直在尝试大量的例子和阅读尽可能多的材料，但我想我可能会遗漏一些东西。对于我的生活，我无法在我的代码中使用它。

任何帮助将不胜感激。我在这里包含了代码。

public class Favourites extends ListActivity implements OnClickListener {

private static final String TAG = "favourites";

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.favourites);

    // Test list of strings- eventually to be replaced 
    String[] values = new String[] { "Android", "iPhone", "WindowsMobile",
              "Blackberry", "WebOS", "Ubuntu", "Windows7", "Max OS X",
              "Linux", "OS/2" };

    // First paramenter - Context
    // Second parameter - Layout for the row
    // Third parameter - ID of the TextView to which the data is written
    // Forth - the Array of data
    ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, android.R.id.text1, values);

    setListAdapter(adapter);
    ListView list = getListView();

    Log.d(TAG,"adapter count: " + adapter.getCount());

    // Define listView Long Click listener
    list.setOnItemLongClickListener(new OnItemLongClickListener() {         
        @Override
        public boolean onItemLongClick(AdapterView<?> parent, View view, int position, long id) {
            String item = (String) getListAdapter().getItem(position);                    

            // Remove Item
            AlertDialog.Builder adb = new AlertDialog.Builder(Favourites.this);
            adb.setTitle("Delete?");
            adb.setMessage("Are you sure you want to remove " + item +" (" + position + ")");
            final int positionToRemove = position;
            final String removeItem = item;

            adb.setNegativeButton("Cancel", null);
            adb.setPositiveButton("Ok", new AlertDialog.OnClickListener() {
            public void onClick(DialogInterface dialog, int which) {        
                // *** Here is where I am experiencing issues ***
                adapter.remove(positionToRemove);
                adapter.notifyDataSetChanged(); 


                Toast.makeText(getApplicationContext(),
                      "Favourite "+ removeItem +" (" + positionToRemove + ") Removed!", Toast.LENGTH_LONG).show();
                }
             });
             adb.show();
             // Return true to consume the click event. In this case the
             // onListItemClick listener is not called anymore.  
             return true;
        }
    });

    // Close button
    View butClose = findViewById(R.id.closeButton);
    butClose.setOnClickListener(this);

    // Add button
    View butAdd = findViewById(R.id.addButton);
    butAdd.setOnClickListener(this);

}

Answer 1

您实际上并未直接从适配器中删除。您必须首先从ArrayList中删除数据。所以，改变

adapter.remove(positionToRemove);
adapter.notifyDataSetChanged();

到

values.remove(positionToRemove);
adapter.notifyDataSetChanged();

Answer 2

对我有用的代码是：

public void onClick(View v) 
{ 
 if (idx != 0) 
 { 
 String delete = (String) ((OdrLst.getAdapter()).getItem(idx));
 //Log.d("Itemdeleted",delete); 
 adapter.remove(delete); 
 adapter.notifyDataSetChanged(); 
 OdrLst.setAdapter(adapter); 
 //Log.d("adapter count after", adapter.getCount() + ""); 
 //Log.d("lv count after", OdrLst.getCount() + ""); 
 } 
}

idx它应该是你的索引位置。

Answer 3

您可以尝试使用对象“适配器”调用getListAdapter()。像

getListAdapter().remove(positionToRemove);
getListAdapter().notifyDataSetChanged();

Answer 4

我在HTC野火和Nexus 7上遇到类似的问题，ListView在删除项目后没有刷新屏幕。然而，一些设备没有遇到这样的问题 - 例如三星S II没有问题

修复很奇怪（至少对我而言），我在布局中从background="@android:color/black"中取出了ListView行，一切都运行良好。

ListView问题删除项目

4 个答案: