Question

调用notifyDataSetChanged后，Listview更新无法正常工作。用户点击构建并更新数据但屏幕永远不会更新？有人可以告诉我为什么负载数据可能无法正常工作？

public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);


      list1 = (ListView) findViewById(R.id.ListView01);
      list1.setAdapter(new ArrayAdapter(this, android.R.layout.simple_list_item_1, array));

      final EditText EditMessage = (EditText) findViewById(R.id.editTextWebSite);
      Button button = (Button) findViewById(R.id.button1);

        button.setOnClickListener(new OnClickListener() {
            public void onClick(View v) {
                String website = EditMessage.getText().toString();

                //String returnString = loaddata(website);
                Toast.makeText(v.getContext(),
                        "Updating Information",
                        Toast.LENGTH_LONG).show();  
                setListData();

                BaseAdapter la = (BaseAdapter)list1.getAdapter();
                ((BaseAdapter) la).notifyDataSetChanged() ;

                Toast.makeText(v.getContext(),
                        "Updated",
                        Toast.LENGTH_LONG).show();  

            }
        });



private void setListData()
    {
        String array2[] = { "Iphone", "Tutorials", "Gallery", "Android",    "item 1", "item 2", "item3", "item 4" };
         System.arraycopy(array, 0, array2, 0, array.length);
    }

Answer 1

尝试

((ArrayAdapter)list1.getAdapter()).notifyDataSetChanged() ;

而不是强制转换为BaseAdapter。

Answer 2

public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

final ArrayAdapter mArrayAdapter=new ArrayAdapter(this, android.R.layout.simple_list_item_1, array);
      list1 = (ListView) findViewById(R.id.ListView01);
      list1.setAdapter(mArrayAdapter);

      final EditText EditMessage = (EditText) findViewById(R.id.editTextWebSite);
      Button button = (Button) findViewById(R.id.button1);

        button.setOnClickListener(new OnClickListener() {
            public void onClick(View v) {
                String website = EditMessage.getText().toString();

                //String returnString = loaddata(website);
                Toast.makeText(v.getContext(),
                        "Updating Information",
                        Toast.LENGTH_LONG).show();  
                setListData();

                mArrayAdapter.notifyDataSetChanged() ;

                Toast.makeText(v.getContext(),
                        "Updated",
                        Toast.LENGTH_LONG).show();  

            }
        });

试试这个可能有帮助

Answer 3

我发现侦听器方法可能无法在UI主线程上运行。您应该确保何时使用

adapter.notifyDataSetChanged()

UI主线程中的

。您可以使用 hander 来解决此问题。

调用notifyDataSetChanged后，Listview更新无法正常工作

3 个答案: