Question

我试图在用户输入EditText时修改ListView的内容。它主要起作用，但奇怪的是它在删除字符时不会恢复列表。通过调试器模式时，我发现有两件事情发生，我不知道为什么。

jobs被修改，即使我在我的代码中没有修改它，据我所知。
在getNewArray方法中，

if(newArray.size() == 0) { return jobs; }
即使newArray.size()为0（在调试器模式下检查）

这是活动：

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.text.Editable;
import android.text.TextWatcher;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.TextView;
import java.util.ArrayList;
import java.util.Arrays;

public class MainActivity extends AppCompatActivity {

String[] stringArray = {"557K", "559B", "601A", "357K", "459B", "501A", "657K", "759B", "801A"};
private ArrayList<String> jobs;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    jobs = new ArrayList<String>(Arrays.asList(stringArray));
    setContentView(R.layout.activity_main);

    ListView listView = (ListView)findViewById(R.id.listView);
    final ArrayAdapter adapter = new ArrayAdapter(this, android.R.layout.simple_list_item_1, jobs);
    listView.setAdapter(adapter);
    final EditText editText = (EditText) findViewById(R.id.editText);

    // set listener for list view. clicked item populates the EditText
    listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
            String text = ((TextView) view).getText().toString();
            String[] subStrings = text.split(" :", 2);
            editText.setText(subStrings[0]);
        }
    });

    // set text watcher to modify content in list as user types into EditText
    TextWatcher textWatcher = new TextWatcher() {

        @Override
        public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) {
        }

        @Override
        public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) {
        }

        @Override
        public void afterTextChanged(Editable editable) {

            // get modified array
            ArrayList<String>  newList = StringMatcher.getNewArray(jobs, editable.toString());

            // refresh viewList
            adapter.clear();
            adapter.addAll(newList);
            adapter.notifyDataSetChanged();

        }
    };
    editText.addTextChangedListener(textWatcher);
}


@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.menu_main, menu);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int id = item.getItemId();

    //noinspection SimplifiableIfStatement
    if (id == R.id.action_settings) {
        return true;
    }

    return super.onOptionsItemSelected(item);
}
}

布局：

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:paddingBottom="@dimen/activity_vertical_margin" tools:context=".MainActivity">


<EditText
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:id="@+id/editText" />

<ListView
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:id="@+id/listView" />

StringMatcher类：

import java.util.ArrayList;

public class StringMatcher {

private StringMatcher(){}

/**
 * Taken from András Belicza
 * http://stackoverflow.com/questions/86780/is-the-contains-method-in-java-lang-string-case-sensitive
 * On 29/10/2015
 * @param src
 * @param what
 * @return
 */
private static boolean containsIgnoreCase(String src, String what) {
    final int length = what.length();
    if (length == 0)
        return true; // Empty string is contained

    final char firstLo = Character.toLowerCase(what.charAt(0));
    final char firstUp = Character.toUpperCase(what.charAt(0));

    for (int i = src.length() - length; i >= 0; i--) {
        // Quick check before calling the more expensive regionMatches() method:
        final char ch = src.charAt(i);
        if (ch != firstLo && ch != firstUp)
            continue;

        if (src.regionMatches(true, i, what, 0, length))
            return true;
    }

    return false;
}

public static ArrayList<String> getNewArray(ArrayList<String> jobs, String newString) {
    ArrayList<String> newArray = new ArrayList<String>();
    for(String job: jobs){
        if(containsIgnoreCase(job,newString))
            newArray.add(job);
    }
    if(newArray.size() == 0) {
        return jobs;
    }
    else {
        return newArray;
    }
}
}

根据用户输入修改ListView

0 个答案: