Android开发实验三

@author 赖昌平

AndroidUI组件

一、实验环境:

Android Studio + Android 5.0

二、实验内容

1.Android ListView的用法

代码

MainActivity.java

package com.lab.labs;import androidx.appcompat.app.AppCompatActivity;import android.os.Bundle;import android.view.View;import android.widget.AdapterView;import android.widget.ListView;import android.widget.SimpleAdapter;import android.widget.Toast;import java.util.ArrayList;import java.util.HashMap;import java.util.List;import java.util.Map;public class MainActivity extends AppCompatActivity {    private String[] names = new String[]            {"Lion","Tiger","Monkey","Dog","Cat","Elephant"};    private int[] imgIds = new int[]            {R.drawable.lion,R.drawable.tiger,R.drawable.monkey,R.drawable.dog,R.drawable.cat,R.drawable.elephant};    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        List<Map<String,Object>> lists = new ArrayList<>();        for (int i = 0;i < names.length;i++){            Map<String,Object> list = new HashMap<>();            list.put("images",imgIds[i]);            list.put("names",names[i]);            lists.add(list);        }        ListView listView = findViewById(R.id.list_view01);        SimpleAdapter simpleAdapter = new SimpleAdapter(MainActivity.this,                lists, R.layout.simple_adapter,                new String[] {"names","images"},                new int[] {R.id.names,R.id.images});        listView.setAdapter(simpleAdapter);        listView.setOnItemClickListener(new AdapterView.OnItemClickListener(){            @Override            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {                Toast toast = Toast.makeText(MainActivity.this,names[position],Toast.LENGTH_SHORT);                toast.show();            }        });    }}

simple_adapter.xml:

<?xml version="1.0" encoding="utf-8"?>xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:app="http://schemas.android.com/apk/res-auto"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:orientation="vertical">    android:id="@+id/names"        android:layout_width="match_parent"        android:layout_height="match_parent"        android:textSize="50dp"         />    android:id="@+id/images"        android:layout_width="70dp"        android:layout_height="70dp"        app:layout_constraintLeft_toRightOf="@id/names"        app:layout_constraintRight_toRightOf="parent"        app:layout_constraintTop_toTopOf="parent"        app:layout_constraintHorizontal_bias="1.0"         />

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>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"    tools:context=".MainActivity"    android:orientation="vertical">    android:id="@+id/list_view01"        android:layout_height="wrap_content"        android:layout_width="match_parent"        tools:ignore="MissingConstraints" />

效果图

2.创建自定义布局的AlertDialog

代码

Main2Activity.java

package com.lab.labs;import android.app.Dialog;import android.content.Context;import android.graphics.Point;import android.os.Bundle;import android.view.Display;import android.view.WindowManager;import androidx.annotation.NonNull;import androidx.appcompat.app.AppCompatActivity;public class Main2Activity extends AppCompatActivity {    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        AlertDialog alertDialog = new AlertDialog(Main2Activity.this);        alertDialog.show();    }}class AlertDialog extends Dialog {    public AlertDialog(@NonNull Context context) {        super(context);    }    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main2);        WindowManager windowManager = getWindow().getWindowManager();        Display display = windowManager.getDefaultDisplay();        WindowManager.LayoutParams p = getWindow().getAttributes();        Point size = new Point();        display.getSize(size);        p.width = size.x;        getWindow().setAttributes(p);    }}

activity_main2.xml

<?xml version="1.0" encoding="utf-8"?>xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="match_parent"    android:layout_height="match_parent"    xmlns:app="http://schemas.android.com/apk/res-auto">    android:id="@+id/title"        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:text="ANDROID APP"        android:textSize="40dp"        android:gravity="center"        android:padding="10dp"        android:textColor="@android:color/white"        android:background="@android:color/holo_orange_light"        app:layout_constraintTop_toTopOf="parent"        />    android:id="@+id/userName"        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:hint=" Username"        app:layout_constraintTop_toBottomOf="@id/title"        android:textSize="25dp"/>    android:id="@+id/password"        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:hint=" Password"        android:textSize="25dp"        android:inputType="textPassword"        app:layout_constraintTop_toBottomOf="@id/userName" />

效果图

3.使用XML定义菜单

代码

Main3Activity.java

package com.lab.labs;import androidx.appcompat.app.AppCompatActivity;import android.graphics.Color;import android.os.Bundle;import android.view.Menu;import android.view.MenuInflater;import android.view.MenuItem;import android.widget.TextView;import android.widget.Toast;public class Main3Activity extends AppCompatActivity {    private TextView test;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main3);        test = findViewById(R.id.test);        registerForContextMenu(test);    }    @Override    public boolean onCreateOptionsMenu(Menu menu) {        MenuInflater menuinflater = getMenuInflater();        menuinflater.inflate(R.menu.menu, menu);        return true;    }    @Override    public boolean onOptionsItemSelected(MenuItem item) {        switch (item.getItemId()) {            case R.id.menu_size_1:                test.setTextSize(11);                return true;            case R.id.menu_size_2:                test.setTextSize(16);                return true;            case R.id.menu_size_3:                test.setTextSize(21);                return true;            case R.id.menu_common:                Toast.makeText(Main3Activity.this,"这是普通菜单项",Toast.LENGTH_SHORT).show();                return true;            case R.id.menu_color_red:                test.setTextColor(Color.RED);                return true;            case R.id.menu_color_yellow:                test.setTextColor(Color.YELLOW);                return true;            default:                return super.onOptionsItemSelected(item);        }    }}

activity_main3.xml(主页面)

<?xml version="1.0" encoding="utf-8"?><androidx.constraintlayout.widget.ConstraintLayout 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"    tools:context=".Main3Activity">    <TextView        android:id="@+id/test"        android:layout_width="0dp"        android:layout_height="wrap_content"        android:text="用于测试的内容"        android:textSize="16dp"        tools:ignore="MissingConstraints" /></androidx.constraintlayout.widget.ConstraintLayout>

menu.xml

<?xml version="1.0" encoding="utf-8"?>xmlns:android="http://schemas.android.com/apk/res/android">    android:id="@+id/menu_size"        android:title="字体大小">        xmlns:android="http://schemas.android.com/apk/res/android">            android:id="@+id/menu_size_1"                android:title="小" />            android:id="@+id/menu_size_2"                android:title="中" />            android:id="@+id/menu_size_3"                android:title="大" />                android:id="@+id/menu_common"        android:title="普通菜单项" />    android:id="@+id/menu_color"        android:title="字体颜色">        xmlns:android="http://schemas.android.com/apk/res/android">            android:id="@+id/menu_color_red"                android:title="红色" />            android:id="@+id/menu_color_yellow"                android:title="黄色" />

效果图

更改字体大小和颜色

4.创建上下文操作模式(ActionMode)的上下文菜单

效果图

结语

本次实验是熟悉Android UI 组件的应用，实验看起来简单，但实现起来蛮复杂的，花了不少时间，参考了不少百度以及其他人的代码才得以完成…虽然很菜但是相信通过不断努力可以有所进步。

实验三、AndroidUI组件