[英]onMenuItemClick switch case selecting multiple cases
出於某種原因,我的開關案例出於某種原因選擇了多個案例。 假設我單擊排序->按名稱,它選擇排序->按名稱,排序->按點和統計信息(如下所示)。 這不是第一次發生,它也發生在代碼的另一部分,我簡單地將其切換為“如果”並忘記了它。 為什么點擊時他會 select 多個值? 為什么隨機值? 開關盒 function:
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;
}
顯示彈出窗口:
public void showPopup(View v) {
PopupMenu popup = new PopupMenu(this, v);
popup.setOnMenuItemClickListener((PopupMenu.OnMenuItemClickListener) this);
popup.inflate(R.menu.popup_menu);
popup.show();
}
菜單:
<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" />
每次敬酒后你應該break
。
從 Tutorialspoint.com 看這個例子
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);
}
}
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