【发布时间】:2017-11-20 14:57:30
【问题描述】:
我为我的应用程序创建了一个侧边菜单(导航菜单),并重写了 OnOptionsItemSelected(MenuItem item) 方法,以便在单击每个菜单项时添加一些自定义行为。但是,在编写了一些代码之后,当单击第一个菜单项时(nav_home
@Override
public boolean onOptionsItemSelected(MenuItem item) {
if(mToggle.onOptionsItemSelected(item)) {
return true;
}
// When a menu item is clicked, then depending on it's id start a new Activity
switch (item.getItemId()) {
case R.id.nav_home:
Toast.makeText(this, "Clicked", Toast.LENGTH_SHORT).show();
break;
default:
return super.onOptionsItemSelected(item);
}
return true;
}
这是我的整个 MainActivity 类:
package com.dcv.spdesigns.dokkancards;
import android.content.Intent;
import android.support.v4.widget.DrawerLayout;
import android.support.v7.app.ActionBarDrawerToggle;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.Toolbar;
import android.util.DisplayMetrics;
import android.view.MenuItem;
import android.view.View;
import android.widget.AdapterView;
import android.widget.GridView;
import android.widget.Toast;
import com.dcv.spdesigns.dokkancards.model.ImageAdapter;
import com.dcv.spdesigns.dokkancards.ui.CardViewActivity;
public class MainActivity extends AppCompatActivity {
GridView gridView;
// NavMenu member vars
private DrawerLayout mDrawerLayout;
private ActionBarDrawerToggle mToggle; // Button for toggling the side menu
private Toolbar mToolbar;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// Get Screen Size Details
DisplayMetrics displayMetrics = new DisplayMetrics();
getWindowManager().getDefaultDisplay().getMetrics(displayMetrics);
int height = displayMetrics.heightPixels;
final int width = displayMetrics.widthPixels;
gridView = (GridView) findViewById(R.id.gridViewLayout);
gridView.setAdapter(new ImageAdapter(this)); // used to set the contents of the GridView-in this case images-
// When an item from the GridView gets clicked
gridView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
// Create a new Intent...
Toast.makeText(MainActivity.this, "Position: " + position, Toast.LENGTH_SHORT).show();
Intent intent = new Intent(MainActivity.this,CardViewActivity.class);
intent.putExtra("Card Index",position);
intent.putExtra("SCREEN_WIDTH",width);
startActivity(intent);
}
});
mToolbar = (Toolbar) findViewById(R.id.navActionBar);
setSupportActionBar(mToolbar); // check quick doq
getSupportActionBar().setDisplayShowTitleEnabled(false);
mToolbar.setTitle("");
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
mDrawerLayout = (DrawerLayout) findViewById(R.id.drawerLayout);
mToggle = new ActionBarDrawerToggle(this,mDrawerLayout,R.string.drawer_open,R.string.drawer_closed); // Instantiating our button
mDrawerLayout.addDrawerListener(mToggle);
mToggle.syncState();
}
// When an item from the Action Bar gets tapped, then...
@Override
public boolean onOptionsItemSelected(MenuItem item) {
if(mToggle.onOptionsItemSelected(item)) {
return true;
}
// When a menu item is clicked, then depending on it's id start a new Activity
switch (item.getItemId()) {
case R.id.nav_home:
Toast.makeText(this, "Clicked", Toast.LENGTH_SHORT).show();
break;
default:
return super.onOptionsItemSelected(item);
}
return true;
}
}
主xml文件:
<?xml version="1.0" encoding="utf-8"?>
<android.support.v4.widget.DrawerLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@color/colorPrimary"
tools:context="com.dcv.spdesigns.dokkancards.MainActivity"
android:id="@+id/drawerLayout">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<!-- Include the custom Action Bar we created -->
<include layout="@layout/navigation_action_bar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="center"/>
<GridView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:columnWidth="90dp"
android:numColumns="4"
android:verticalSpacing="10dp"
android:horizontalSpacing="10dp"
android:stretchMode="columnWidth"
android:gravity="center"
android:id="@+id/gridViewLayout"/>
<!-- Add text & images -->
</LinearLayout>
<!-- The actual side menu Nav View -->
<android.support.design.widget.NavigationView
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:layout_gravity="start"
app:headerLayout="@layout/navigation_header"
app:menu="@menu/navigation_menu">
</android.support.design.widget.NavigationView>
</android.support.v4.widget.DrawerLayout>
【问题讨论】:
-
评论条件:if(mToggle.onOptionsItemSelected(item)) {
-
我试过了,但没用
-
a Toast will be displayed,nothing happens,没有别的了,你在期待什么 -
我不期待更多...但就像我说的那样,这不起作用。不显示 Toasts
-
发布完整代码
标签: java android switch-statement onclicklistener