添加/从我的列表视图中删除的项目？ [英] Adding/Removing items from my listview?

问题描述

下code使得从字符串[]演习项目清单。您也可以通过搜索过滤。

问题是，我有两个纺纱厂，这将需要过滤列表中的项目。所以我的问题是，我该如何添加/删除字符串从列表以后？

 公共类CalExercises延伸活动{
        私人的ListView myListView;
        ArrayAdapter＆LT;串GT; myAdapter;
        的EditText inputSearch;
        ArrayList的＆LT;＆HashMap的LT;字符串，字符串＆GT;＆GT; productList的;
        @覆盖
        公共无效的onCreate（捆绑savedInstanceState）{
            super.onCreate（savedInstanceState）;
            的setContentView（R.layout.activity_calexercise）;
            字符串演习[] = {奥拉，DOLLA};
            myListView =（ListView控件）findViewById（R.id.exp_list）;
            inputSearch =（EditText上）findViewById（R.id.itemSearch）;
            myAdapter =新ArrayAdapter＆LT;串GT;（这一点，R.layout.parent_layout，R.id.parent_txt，练习）;
            myListView.setAdapter（myAdapter）;
            inputSearch.addTextChangedListener（新TextWatcher（）{
                @覆盖
                公共无效onTextChanged（CharSequence的CS，INT ARG1，ARG2 INT，INT ARG3）{
                   。CalExercises.this.myAdapter.getFilter（）过滤器（CS）;
                }
                @覆盖
                公共无效beforeTextChanged（CharSequence的为arg0，ARG1 INT，INT ARG2，
                                              INT ARG3）{
                }
                @覆盖
                公共无效afterTextChanged（编辑为arg0）{
                }
            }）;            最后的微调spindif =（微调）findViewById（（R.id.filterDif））;
            最后的微调spinmus =（微调）findViewById（（R.id.filterMus））;
            最后弦乐diffilter =将String.valueOf（spindif.getSelectedItem（））;
            最后弦乐musfilter =将String.valueOf（spinmus.getSelectedItem（））;            如果（diffilter.equals（所有练习））{            }
        }    }
 

解决方案

如果你需要创建一个只包含的项目匹配的字符串数组，创建一个新的数组并把它分配给练习：

  =行使filterArray（练习，过滤器）;
myAdapter.notifyDataSetChanged（）;的String [] filterArray（字符串[]编曲，弦乐过滤器）{
  ArrayList的＆LT;串GT; newArray =新的ArrayList＆LT;串GT;（）;
  的for（int i = 0; I＆LT; arr.length（）＆LT;我++）{
    如果（ARR [I]。载有（过滤器）{
      （ARR [I]）newArray.add;
    }
  }
  返回newArray.toArray（）;
}
 

如果您需要添加到阵列...

  =行使addToArray（练习，newString）;
myAdapter.notifyDataSetChanged（）;的String [] addToArray（字符串[]编曲，弦乐newString）{
  ArrayList的＆LT;串GT; newArray =新的ArrayList＆LT;串GT;（ARR）;
  arr.add（newString）;
  返回newArray.toArray（）;
}
 

如果您需要从数组中删除...

 练习= removeFromArray（练习，newString）;
myAdapter.notifyDataSetChanged（）;的String [] removeFromArray（字符串[]编曲，弦乐removeMe）{
  ArrayList的＆LT;串GT; newArray =新的ArrayList＆LT;串GT;（ARR）;
  对于（字符串项：newArray）{
    如果（item.equals（removeMe）{
      newArray.remove（项目）;
    }
  }
  返回newArray.toArray（）;
}
 

The code below makes a list with the items from the string[] exercises. You can also filter it by searching.

The problem is, I have two spinners that will need to filter the items in the list. So my question is, how do I add/remove strings from the list later on?

public class CalExercises extends Activity {
        private ListView myListView;
        ArrayAdapter<String> myAdapter;
        EditText inputSearch;
        ArrayList<HashMap<String, String>> productList;
        @Override
        public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_calexercise);
            String exercises[] = { "Ola", "dolla" };
            myListView = (ListView) findViewById(R.id.exp_list);
            inputSearch = (EditText) findViewById(R.id.itemSearch);
            myAdapter = new ArrayAdapter<String>(this, R.layout.parent_layout, R.id.parent_txt, exercises);
            myListView.setAdapter(myAdapter);
            inputSearch.addTextChangedListener(new TextWatcher() {
                @Override
                public void onTextChanged(CharSequence cs, int arg1, int arg2, int arg3) {
                   CalExercises.this.myAdapter.getFilter().filter(cs);
                }
                @Override
                public void beforeTextChanged(CharSequence arg0, int arg1, int arg2,
                                              int arg3) {
                }
                @Override
                public void afterTextChanged(Editable arg0) {
                }
            });

            final Spinner spindif = (Spinner) findViewById((R.id.filterDif));
            final Spinner spinmus = (Spinner) findViewById((R.id.filterMus));
            final String diffilter = String.valueOf(spindif.getSelectedItem());
            final String musfilter = String.valueOf(spinmus.getSelectedItem());

            if (diffilter.equals("All Exercises")) {

            }


        }

    }

解决方案

If you need to create an array that only contains items matching a string, create a new array and assign it to exercises:

exercises = filterArray(exercises, filter);  
myAdapter.notifyDataSetChanged();

String[] filterArray(String[] arr, String filter) {
  ArrayList<String> newArray = new ArrayList<String>();
  for (int i=0;i<arr.length()<i++) {
    if (arr[i].contains(filter) {
      newArray.add(arr[i]);
    }
  }
  return newArray.toArray();
}

If you need to add to the array...

exercises = addToArray(exercises, newString);
myAdapter.notifyDataSetChanged();

String[] addToArray(String[] arr, String newString) {
  ArrayList<String> newArray = new ArrayList<String>(arr);
  arr.add(newString);
  return newArray.toArray();
}

If you need to remove from the array...

exercises = removeFromArray(exercises, newString);
myAdapter.notifyDataSetChanged();

String[] removeFromArray(String[] arr, String removeMe) {
  ArrayList<String> newArray = new ArrayList<String>(arr);
  for (String item: newArray) {
    if (item.equals(removeMe) {
      newArray.remove(item);
    }
  }
  return newArray.toArray();
}

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