安卓常用View(视图开发技巧总结)

本篇常用的View如图中所示：

xml布局代码

<?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">
<Button
    android:id="@+id/btn_menu_contextMenu"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:text="显示ContentMenu"/>
    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="1.点击menu显示选项菜单\n2.长按按钮显示上下文菜单"
        android:textSize="25sp"/>

</LinearLayout>

menu-xml代码

<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android">

    <item android:title="添加2"
        android:id="@+id/add">

    </item>
    <item android:title="删除2"
        android:id="@+id/delete">

    </item>

</menu>

java代码

public class MenuActivity extends AppCompatActivity {
    private Button btn_menu_contextMenu;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_menu);
        Button btn_menu_contextMenu = findViewById(R.id.btn_menu_contextMenu);
        btn_menu_contextMenu.setOnCreateContextMenuListener(this);
    }

    @Override
    public void onCreateContextMenu(ContextMenu menu, View v, ContextMenu.ContextMenuInfo menuInfo) {
        menu.add(0, 4, 0, "添加");
        menu.add(0, 5, 0, "删除");
        super.onCreateContextMenu(menu, v, menuInfo);
    }

    @Override
    public boolean onContextItemSelected(MenuItem item) {
        switch (item.getItemId()) {
            case 4:
                Toast.makeText(this, item.getTitle(), Toast.LENGTH_SHORT).show();
                break;
            case 5:
                Toast.makeText(this, item.getTitle(), Toast.LENGTH_SHORT).show();
                break;
        }
        return super.onContextItemSelected(item);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
//        menu.add(0, 2, 0, "添加");
//        menu.add(0, 3, 0, "删除");
        MenuInflater menuInflater = getMenuInflater();
        menuInflater.inflate(R.menu.option_menu, menu);
        return super.onCreateOptionsMenu(menu);
    }


    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()) {
            case 2:
                Toast.makeText(this, item.getTitle(), Toast.LENGTH_SHORT).show();
                break;
            case 3:
                Toast.makeText(this, item.getTitle(), Toast.LENGTH_SHORT).show();
                break;
            case R.id.add:
                Toast.makeText(this, item.getTitle(), Toast.LENGTH_SHORT).show();
                break;
            case R.id.delete:
                Toast.makeText(this, item.getTitle(), Toast.LENGTH_SHORT).show();
                break;
        }
        return super.onOptionsItemSelected(item);
    }
} 

总结：
OptionMenu
1. 如何触发Menu的显示?
点击menu键
2. 如何向Menu中添加MenuItem?
重写onCreateOptionMenu()
menu.add()或者加载菜单文件
3. 选择某个MenuItem时如何响应?
重写onOptionsItemSelected(), 根据itemId做响应
ContextMenu
1. 如何触发Menu的显示?
长按某个视图
view.setOnCreateContextMenuListener(this)
2. 如何向Menu中添加MenuItem?
重写onCreateContextMenu()
menu.add()
3. 选择某个MenuItem时如何响应?
重写onContextItemSelected(), 根据itemId做响应

本文地址：https://blog.csdn.net/we1less/article/details/107733441