我很好奇如何使用可搜索的自定义适配器制作列表视图。我按照教程进行了所有设置,但是当我尝试在 EditText 中键入任何内容时应用程序崩溃。现在我知道为什么应用程序崩溃了,我只是不知道如何修复它。
这是我的 MainActivity 的代码:
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Context ctx = getApplication();
Resources res = ctx.getResources();
String[] options = res.getStringArray(R.array.item_ids);
String[] ids = res.getStringArray(R.array.item_names);
TypedArray icons = res.obtainTypedArray(R.array.item_images);
setListAdapter(new ItemIDAdapter(ctx, R.layout.idslistitem, ids, options, icons));
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Get the options menu view from menu.xml in menu folder
getSupportMenuInflater().inflate(R.menu.items_menu, menu);
// Locate the EditText in menu.xml
editsearch = (EditText) menu.findItem(R.id.menu_search).getActionView();
// Capture Text in EditText
editsearch.addTextChangedListener(textWatcher);
// Show the search menu item in menu.xml
MenuItem menuSearch = menu.findItem(R.id.menu_search);
menuSearch.setOnActionExpandListener(new OnActionExpandListener() {
// Menu Action Collapse
@Override
public boolean onMenuItemActionCollapse(MenuItem item) {
// Empty EditText to remove text filtering
editsearch.setText("");
editsearch.clearFocus();
return true;
}
// Menu Action Expand
@Override
public boolean onMenuItemActionExpand(MenuItem item) {
// Focus on EditText
editsearch.requestFocus();
// Force the keyboard to show on EditText focus
InputMethodManager imm = (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);
imm.toggleSoftInput(InputMethodManager.SHOW_FORCED, 0);
return true;
}
});
// Show the settings menu item in menu.xml
MenuItem menuSettings = menu.findItem(R.id.home);
// Capture menu item clicks
menuSettings.setOnMenuItemClickListener(new OnMenuItemClickListener() {
@Override
public boolean onMenuItemClick(MenuItem item) {
Intent intent2 = new Intent(ItemId.this, Home.class);
startActivity(intent2);
return true;
}
});
return true;
}
// EditText TextWatcher
private TextWatcher textWatcher = new TextWatcher() {
@Override
public void afterTextChanged(Editable s) {
// TODO Auto-generated method stub
String text = editsearch.getText().toString()
.toLowerCase(Locale.getDefault());
adapter.getFilter().filter(text);
}
@Override
public void beforeTextChanged(CharSequence arg0, int arg1, int arg2,
int arg3) {
// TODO Auto-generated method stub
}
@Override
public void onTextChanged(CharSequence arg0, int arg1, int arg2,
int arg3) {
// TODO Auto-generated method stub
}
};
这是我的自定义列表视图适配器的代码:
public class ItemIDAdapter extends ArrayAdapter<String> {
public LayoutInflater mInflater;
public String[] mStrings;
public String[] mIds;
public TypedArray mIcons;
public int mViewResourceId;
ArrayAdapter<String> adapter;
public ItemIDAdapter(Context ctx, int viewResourceId,
String[] strings, String[] ids, TypedArray icons) {
super(ctx, viewResourceId, strings);
mInflater = (LayoutInflater)ctx.getSystemService(
Context.LAYOUT_INFLATER_SERVICE);
mStrings = strings;
mIds = ids;
mIcons = icons;
mViewResourceId = viewResourceId;
}
@Override
public int getCount() {
return mStrings.length;
}
@Override
public String getItem(int position) {
return mStrings[position];
}
@Override
public long getItemId(int position) {
return position;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
convertView = mInflater.inflate(mViewResourceId, null);
ImageView iv = (ImageView)convertView.findViewById(R.id.option_icon);
iv.setImageDrawable(mIcons.getDrawable(position));
TextView tv = (TextView)convertView.findViewById(R.id.option_text);
tv.setText(mStrings[position]);
TextView tv1 = (TextView)convertView.findViewById(R.id.itemids);
tv1.setText(mIds[position]);
return convertView;
}
}
当我尝试搜索时应用程序崩溃的原因是因为在 TextWatcher 中,这一行:adapter.getFilter().filter(text);
适配器仅在我的主要活动的顶部定义,但它根本不与我的列表视图一起使用。我被困在这里,真的不知道用什么替换adapter
,因为 ItemIDAdapter 不起作用。谢谢你的帮助!