这是我的代码
home.xml
<item
android:id="@+id/action_shopping_cart"
android:actionLayout="@layout/action_bar_cart_button"
android:showAsAction="ifRoom"
android:title="Shopping Cart" />
<item
android:id="@+id/action_notifications"
android:actionLayout="@layout/action_bar_notifications_button"
android:showAsAction="ifRoom"
android:title="Notifications" />
<item
android:id="@+id/menu_overflow"
android:orderInCategory="100"
android:icon="@drawable/ic_action_overflow"
android:showAsAction="always"
android:title="OverFlow">
<menu>
<item
android:id="@+id/action_my_account"
android:orderInCategory="100"
android:showAsAction="never"
android:title="My Account" />
<item
android:id="@+id/action_current_orders"
android:orderInCategory="100"
android:showAsAction="never"
android:title="My Orders" />
<item
android:id="@+id/action_wish_list"
android:orderInCategory="100"
android:showAsAction="never"
android:title="My Wishlist" />
<item
android:id="@+id/action_contact_us"
android:orderInCategory="100"
android:showAsAction="never"
android:title="Contact Us" />
<item
android:id="@+id/action_logout"
android:orderInCategory="100"
android:showAsAction="never"
android:title="Logout" />
</menu>
</item>
我想查看&#34; menu_overflow&#34; 我该怎么做?
我试过以下方式:
Activity.java 代码
public boolean onCreateOptionsMenu(菜单菜单){
final MenuItem item = menu.findItem(R.id.menu_overflow);
View view = (View) findViewById(R.id.menu_overflow);
new MaterialShowcaseView.Builder(this)
.setTarget(mOverFlowIcon)
.setRadius(10)
.setMaskColour(Color.argb(150, 0, 0, 0))
.setContentText("Find Your Wishlist Here") // optional but starting animations immediately in onCreate can make them choppy
.setDismissOnTouch(true)
.show();
return super.onCreateOptionsMenu(menu);
}
但是返回视图是 null 。
请帮助... thanx
答案 0 :(得分:11)
你是否在onCreateOptionsMenu中夸大了菜单?看来,当执行onCreateOptionsMenu时,xml通胀会被添加到事件队列中,而不是立即膨胀。这是执行findViewById()时导致空指针的原因。尝试将视图查找放在Handler中。 Handler中的代码被添加到消息队列中,因此将在菜单膨胀后执行。这将解决您的空指针。它看起来像这样:
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main, menu);
new Handler().post(new Runnable() {
@Override
public void run() {
View view = (View) findViewById(R.id.menu_overflow);
new MaterialShowcaseView.Builder(this)
.setTarget(view)
.setRadius(10)
.setMaskColour(Color.argb(150, 0, 0, 0))
.setContentText("Find Your Wishlist Here") // optional but starting animations immediately in onCreate can make them choppy
.setDismissOnTouch(true)
.show();
}
});
return true;
}
答案 1 :(得分:3)
您可以通过覆盖MenuItem
方法获取对onPrepareOptionsMenu(Menu)
的引用:
@Override
public boolean onPrepareOptionsMenu(Menu menu) {
MenuItem actionViewItem = menu.findItem(R.id.your_menu_item);
return super.onPrepareOptionsMenu(menu);
}
如果您想要引用ActionView
,可以使用MenuItemCompat.getActionView(MenuItem)
方法执行此操作:
@Override
public boolean onPrepareOptionsMenu(Menu menu) {
MenuItem actionViewItem = menu.findItem(R.id.your_menu_item);
View v = MenuItemCompat.getActionView(actionViewItem);
return super.onPrepareOptionsMenu(menu);
}
答案 2 :(得分:0)
你试过这个吗?
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
switch (item.getItemId()){
case R.id.action_shopping_cart:
Toast.makeText(this, "action_shopping_cart", Toast.LENGTH_SHORT).show();
break;
case R.id.action_notifications:
Toast.makeText(this, "action_notifications", Toast.LENGTH_SHORT).show();
break;
case R.id.menu_overflow:
Toast.makeText(this, "menu_overflow", Toast.LENGTH_SHORT).show();
break;
case R.id.action_my_account:
Toast.makeText(this, "action_my_account", Toast.LENGTH_SHORT).show();
break;
case R.id.action_current_orders:
Toast.makeText(this, "action_current_orders", Toast.LENGTH_SHORT).show();
break;
case R.id.action_wish_list:
Toast.makeText(this, "action_wish_list", Toast.LENGTH_SHORT).show();
break;
case R.id.action_contact_us:
Toast.makeText(this, "action_contact_us", Toast.LENGTH_SHORT).show();
break;
case R.id.action_logout:
Toast.makeText(this, "action_logout", Toast.LENGTH_SHORT).show();
break;
}
return super.onOptionsItemSelected(item);
}
注意xml的名称(即home.xml)
答案 3 :(得分:0)
尝试:
<item
android:id="@+id/menu_overflow"
android:orderInCategory="100"
android:icon="@drawable/ic_action_overflow"
android:title="OverFlow"
app:showAsAction="always"
app:actionViewClass="android.widget.ImageButton">
请注意以下几行:
app:showAsAction="always"
app:actionViewClass="android.widget.ImageButton"