MainActivity.java
package com.jing.example.nknu_.arraylistplan;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.EditText;
import android.widget.TextView;
import java.util.ArrayList;
public class MainActivity extends AppCompatActivity {
TextView txv;
EditText edtxv;
ArrayList NameList;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
txv = (TextView)findViewById(R.id.textView);
edtxv = (EditText)findViewById(R.id.editText);
NameList = new ArrayList();
NameList.add("Apple");
NameList.add("Banana");
NameList.add("Cow");
NameList.add("1");
NameList.add("2");
}
//尋找目標的位置
public void Find(View v){
String st = edtxv.getText().toString();
int idx = NameList.indexOf(st);
txv.setText(String.valueOf(idx));
}
//增加項目
public void Add(View v){
NameList.add(edtxv.getText());
}
}
AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.jing.example.nknu_.arraylistplan">
<application
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:supportsRtl="true"
android:theme="@style/AppTheme">
<activity
android:name=".MainActivity"
android:label="@string/app_name"
android:theme="@style/AppTheme.NoActionBar">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
content_main.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
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"
app:layout_behavior="@string/appbar_scrolling_view_behavior"
tools:context="com.jing.example.nknu_.arraylistplan.MainActivity"
tools:showIn="@layout/activity_main">
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="find"
android:id="@+id/button"
android:onClick="Find"
android:layout_centerVertical="true"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true"
android:layout_marginLeft="36dp"
android:layout_marginStart="36dp" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="New Text"
android:id="@+id/textView"
android:layout_marginTop="66dp"
android:layout_alignParentTop="true"
android:layout_alignLeft="@+id/button"
android:layout_alignStart="@+id/button" />
<EditText
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/editText"
android:layout_above="@+id/button"
android:layout_centerHorizontal="true"
android:layout_marginBottom="52dp" />
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="New Button"
android:id="@+id/button2"
android:layout_alignBottom="@+id/button"
android:layout_toRightOf="@+id/button"
android:layout_toEndOf="@+id/button"
android:layout_marginLeft="51dp"
android:layout_marginStart="51dp"
android:onClick="Add" />
</RelativeLayout>