onMenuItemClick 切换案例选择多个案例

Question

出于某种原因，我的 switch case 是 selecting 多个 case。假设我单击排序 -> 按名称，它 selects 排序 -> 按名称，排序 -> 按点和统计信息（如下所示）。这不是第一次发生，它也发生在代码的另一部分，我简单地将它切换为“如果”并忘记了它。为什么他会 select 点击多个值？为什么随机值？开关盒功能：

    public boolean onMenuItemClick(MenuItem item) {
    switch (item.getItemId()) {
        case R.id.optionsMenu_saveListDevice:
            Toast.makeText(this, "saveDevice", Toast.LENGTH_SHORT).show();
        case R.id.optionsMenu_saveListServer:
            Toast.makeText(this, "saveServer", Toast.LENGTH_SHORT).show();
        case R.id.optionsMenu_about:
            Toast.makeText(this, "about", Toast.LENGTH_SHORT).show();
        case R.id.optionsMenu_sortByGrade:
            Toast.makeText(this, "sortGrade", Toast.LENGTH_SHORT).show();
        case R.id.optionsMenu_sortByName:
            Toast.makeText(this, "sortName", Toast.LENGTH_SHORT).show();
        case R.id.optionsMenu_sortByPoints:
            Toast.makeText(this, "sortPoints", Toast.LENGTH_SHORT).show();
        case R.id.optionsMenu_statistics:
            Toast.makeText(this, "statistics", Toast.LENGTH_SHORT).show();
        default:
            return false;
    }

显示弹出窗口：

    public void showPopup(View v) {
    PopupMenu popup = new PopupMenu(this, v);
    popup.setOnMenuItemClickListener((PopupMenu.OnMenuItemClickListener) this);
    popup.inflate(R.menu.popup_menu);
    popup.show();
}

菜单：

<menu xmlns:android="http://schemas.android.com/apk/res/android">
<item
    android:id="@+id/optionsMenu_sort"
    android:title="Sort">
    <menu>
        <item
            android:id="@+id/optionsMenu_sortByName"
            android:title="By name" />
        <item
            android:id="@+id/optionsMenu_sortByGrade"
            android:title="By grade" />
        <item
            android:id="@+id/optionsMenu_sortByPoints"
            android:title="By points" />
    </menu>
</item>
<item
    android:id="@+id/optionsMenu_save"
    android:title="Save">
    <menu>
        <item
            android:id="@+id/optionsMenu_saveListDevice"
            android:title="On device" />
        <item
            android:id="@+id/optionsMenu_saveListServer"
            android:title="On server" />
    </menu>
</item>

<item
    android:id="@+id/optionsMenu_statistics"
    android:title="Statistics" />
<item
    android:id="@+id/optionsMenu_about"
    android:title="About" />

Answer 1

每次祝酒后你应该放一个break。

请参阅 Tutorialspoint.com

中的示例

public class Test {

   public static void main(String args[]) {
      // char grade = args[0].charAt(0);
      char grade = 'C';

      switch(grade) {
         case 'A' :
            System.out.println("Excellent!"); 
            break;
         case 'B' :
         case 'C' :
            System.out.println("Well done");
            break;
         case 'D' :
            System.out.println("You passed");
         case 'F' :
            System.out.println("Better try again");
            break;
         default :
            System.out.println("Invalid grade");
      }
      System.out.println("Your grade is " + grade);
   }
}

onMenuItemClick 切换案例选择多个案例

onMenuItemClick switch case selecting multiple cases

android

menu

popupmenu

switch-statement

onclicklistener