Android EditText with TextWatcher (從ListView中搜索數據)

Android EditText 是TextView的子類。愛掏網 - it200.comEditText用于輸入和修改文本。愛掏網 - it200.com在使用EditText的寬度時，我們必須在EditText的inputType屬性中指定其輸入類型，根據輸入配置鍵盤。愛掏網 - it200.com

EditText使用 TextWatcher 接口來監聽對EditText的更改。愛掏網 - it200.com為此，EditText調用 addTextChangedListener() 方法。愛掏網 - it200.com

TextWatcher的方法

1. beforeTextChanged(CharSequence arg0, int arg1, int arg2, int arg3): 在對EditText進行任何更改之前執行。愛掏網 - it200.com
2. onTextChanged(CharSequence cs, int arg1, int arg2, int arg3): 在對EditText進行任何更改時執行。愛掏網 - it200.com
3. afterTextChanged(Editable arg0): 在對EditText進行更改后執行。愛掏網 - it200.com

EditText與TextWatcher()的示例

在這個示例中，我們將使用EditText和TextWatcher來從ListView中搜索數據。愛掏網 - it200.com

activity_main.xml

在layout文件夾中創建一個activity_main.xml文件，其中包含EditText和ListView。愛掏網 - it200.com

文件：activity_main.xml

<?xml version="1.0" encoding="utf-8"?>  
<RelativeLayout 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:paddingBottom="@dimen/activity_vertical_margin"  
    android:paddingLeft="@dimen/activity_horizontal_margin"  
    android:paddingRight="@dimen/activity_horizontal_margin"  
    android:paddingTop="@dimen/activity_vertical_margin"  
    tools:context="com.example.test.searchfromlistview.MainActivity">  

    <EditText  
        android:layout_width="wrap_content"  
        android:layout_height="wrap_content"  
        android:id="@+id/editText"  
        android:inputType="text"  
        android:layout_alignParentTop="true"  
        android:layout_alignParentLeft="true"  
        android:layout_alignParentStart="true"  
        android:layout_alignParentRight="true"  
        android:layout_alignParentEnd="true" />  

    <ListView  
        android:layout_width="wrap_content"  
        android:layout_height="wrap_content"  
        android:id="@+id/listView"  
        android:layout_below="@+id/editText"  
        android:layout_alignParentLeft="true"  
        android:layout_alignParentStart="true" />  
</RelativeLayout>  

在layout文件夾中創建另一個名為list_item.xml的文件，其中包含ListView的數據。愛掏網 - it200.com

list_item.xm

文件：list_item.xml

<?xml version="1.0" encoding="utf-8"?>  
<LinearLayout  
    xmlns:android="http://schemas.android.com/apk/res/android"  
    android:orientation="vertical"  
    android:layout_width="match_parent"  
    android:layout_height="match_parent">  

<TextView android:id="@+id/product_name"  
    android:layout_width="fill_parent"  
    android:layout_height="wrap_content"  
    android:padding="10dip"  
    android:textSize="16dip"  
    android:textStyle="bold"/>  
</LinearLayout>  

Activity類

Activity類

package com.example.test.searchfromlistview;

import android.os.Bundle;
import android.text.Editable;
import android.text.TextWatcher;
import android.widget.ArrayAdapter;
import android.widget.EditText;
import android.widget.ListView;
import android.support.v7.app.AppCompatActivity;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {

    private ListView lv;
    private EditText editText;
    private ArrayAdapter adapter;

    private String products[] = {"Apple", "Banana","Pinapple", "Orange", "Papaya", "Melon",
            "Grapes", "Water Melon","Lychee", "Guava", "Mango", "Kivi"};
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        lv = (ListView) findViewById(R.id.listView);
        editText = (EditText) findViewById(R.id.editText);
        adapter = new ArrayAdapter(this, R.layout.list_item, R.id.product_name, products);
        lv.setAdapter(adapter);

        editText.addTextChangedListener(new TextWatcher() {

            @Override
            public void onTextChanged(CharSequence cs, int arg1, int arg2, int arg3) {
                adapter.getFilter().filter(cs);
            }

            @Override
            public void beforeTextChanged(CharSequence arg0, int arg1, int arg2, int arg3) {
                Toast.makeText(getApplicationContext(),"before text change",Toast.LENGTH_LONG).show();
            }

            @Override
            public void afterTextChanged(Editable arg0) {
                Toast.makeText(getApplicationContext(),"after text change",Toast.LENGTH_LONG).show();
            }
        });
    }
}

輸出