瘋狂 Android 講義, 4/e –菜單(Menu)/子選單(SubMenu) P171~P176
瘋狂 Android 講義, 4/e –菜單(Menu)/子選單(SubMenu) P171~P176
資料來源:
https://github.com/daichangya/book/tree/master/android
https://pan.baidu.com/s/1d_xYJI0UQ_1tQzSj_V_NIg 提取码:70ch
XML Code
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical"> <TextView android:id="@+id/txt" android:padding="12dp" android:layout_width="match_parent" android:layout_height="wrap_content" android:text="用于测试的内容" /> </LinearLayout>
Java Code
package org.crazyit.ui;
import android.app.Activity;
import android.graphics.Color;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.SubMenu;
import android.widget.TextView;
import android.widget.Toast;
/**
* Description:<br>
* 网站: <a href="http://www.crazyit.org">疯狂Java联盟</a><br>
* Copyright (C), 2001-2020, Yeeku.H.Lee<br>
* This program is protected by copyright laws.<br>
* Program Name:<br>
* Date:<br>
*
* @author Yeeku.H.Lee kongyeeku@163.com<br>
* @version 1.0
*/
public class MainActivity extends Activity
{
// 定义“字体大小”菜单项的标识
private static final int FONT_10 = 0x111;
private static final int FONT_12 = 0x112;
private static final int FONT_14 = 0x113;
private static final int FONT_16 = 0x114;
private static final int FONT_18 = 0x115;
// 定义“普通菜单项”的标识
private static final int PLAIN_ITEM = 0x11b;
// 定义“字体颜色”菜单项的标识
private static final int FONT_RED = 0x116;
private static final int FONT_BLUE = 0x117;
private static final int FONT_GREEN = 0x118;
private TextView text;
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
text = findViewById(R.id.txt);
}
// 当用户单击MENU键时触发该方法
@Override public boolean onCreateOptionsMenu(Menu menu)
{
// -------------向menu中添加“字体大小”的子菜单-------------
SubMenu fontMenu = menu.addSubMenu("字体大小");
// 设置菜单的图标
fontMenu.setIcon(R.drawable.font);
// 设置菜单头的图标
fontMenu.setHeaderIcon(R.drawable.font);
// 设置菜单头的标题
fontMenu.setHeaderTitle("选择字体大小");
fontMenu.add(0, FONT_10, 0, "10号字体");
fontMenu.add(0, FONT_12, 0, "12号字体");
fontMenu.add(0, FONT_14, 0, "14号字体");
fontMenu.add(0, FONT_16, 0, "16号字体");
fontMenu.add(0, FONT_18, 0, "18号字体");
// -------------向menu中添加“普通菜单项”-------------
menu.add(0, PLAIN_ITEM, 0, "普通菜单项");
// -------------向menu中添加“字体颜色”的子菜单-------------
SubMenu colorMenu = menu.addSubMenu("字体颜色");
colorMenu.setIcon(R.drawable.color);
// 设置菜单头的图标
colorMenu.setHeaderIcon(R.drawable.color);
// 设置菜单头的标题
colorMenu.setHeaderTitle("选择文字颜色");
colorMenu.add(0, FONT_RED, 0, "红色");
colorMenu.add(0, FONT_GREEN, 0, "绿色");
colorMenu.add(0, FONT_BLUE, 0, "蓝色");
return super.onCreateOptionsMenu(menu);
}
// 选项菜单的菜单项被单击后的回调方法
@Override public boolean onOptionsItemSelected(MenuItem mi)
{
// 判断单击的是哪个菜单项，并有针对性地做出响应
switch (mi.getItemId())
{
case FONT_10: text.setTextSize(10 * 2); break;
case FONT_12: text.setTextSize(12 * 2); break;
case FONT_14: text.setTextSize(14 * 2); break;
case FONT_16: text.setTextSize(16 * 2); break;
case FONT_18: text.setTextSize(18 * 2); break;
case FONT_RED: text.setTextColor(Color.RED); break;
case FONT_GREEN: text.setTextColor(Color.GREEN); break;
case FONT_BLUE: text.setTextColor(Color.BLUE); break;
case PLAIN_ITEM:
Toast.makeText(MainActivity.this,
"您单击了普通菜单项", Toast.LENGTH_SHORT)
.show();
break;
}
return true;
}
}