Android ActionMode 核心机制解析
ActionMode 是 Android 提供的上下文操作模式实现方案,可临时接管 ActionBar 区域提供情境化功能。以下通过实例演示其基础实现:
布局文件定义主界面元素:
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:id="@+id/main_text"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="点击触发模式"/>
</RelativeLayout>
OptionMenu 菜单配置:
<menu xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto">
<item android:id="@+id/opt_item1"
android:title="操作1"
app:showAsAction="always"/>
<item android:id="@+id/opt_item2"
android:title="操作2"
app:showAsAction="always"/>
</menu>
ActionMode 菜单配置:
<menu xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto">
<item android:id="@+id/mode_item1"
android:title="模式操作1"/>
<item android:id="@+id/mode_item2"
android:title="模式操作2"/>
</menu>
Java 逻辑实现:
public class MainActivity extends AppCompatActivity {
private TextView mainText;
@Override
protected void onCreate(Bundle state) {
super.onCreate(state);
setContentView(R.layout.activity_main);
mainText = findViewById(R.id.main_text);
mainText.setOnClickListener(v ->
startActionMode(new ModeHandler())
);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.option_menu, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
int id = item.getItemId();
if (id == R.id.opt_item1) {
Toast.makeText(this, "常规操作1", LENGTH_SHORT).show();
} else if (id == R.id.opt_item2) {
Toast.makeText(this, "常规操作2", LENGTH_SHORT).show();
}
return true;
}
private class ModeHandler implements ActionMode.Callback {
@Override
public boolean onCreateActionMode(ActionMode mode, Menu menu) {
mode.getMenuInflater().inflate(R.menu.action_menu, menu);
return true;
}
@Override
public boolean onActionItemClicked(ActionMode mode, MenuItem item) {
int id = item.getItemId();
if (id == R.id.mode_item1) {
Toast.makeText(MainActivity.this, "模式操作1", LENGTH_SHORT).show();
} else if (id == R.id.mode_item2) {
Toast.makeText(MainActivity.this, "模式操作2", LENGTH_SHORT).show();
}
mode.finish();
return true;
}
@Override
public boolean onPrepareActionMode(ActionMode mode, Menu menu) {
return false;
}
@Override
public void onDestroyActionMode(ActionMode mode) {
}
}
}
关键生命周期方法:
- onCreateActionMode:初始化操作菜单
- onActionItemClicked:处理菜单项点击事件
- onDestroyActionMode:清理操作资源
样式定制示例(styles.xml):
<item name="actionModeBackground">@drawable/custom_bg</item>
<item name="actionModeCloseDrawable">@drawable/custom_close_icon</item>
<item name="actionModeStyle">@style/CustomActionMode</item>
