Question

我是Android开发的新手，所以这可能是一个新手的错误，但是我被卡住了。

我想在点击菜单时启动一项活动，但会出现以下异常：

java.lang.RuntimeException：无法启动活动 ComponentInfo {com.mygymroutine.mygymroutine / com.mygymroutine.mygymroutine.activities.ActivitySchedule}： java.lang.IllegalArgumentException：找不到id 0x7f0d008b的视图片段（com.mygymroutine.mygymroutine：id / fragment_schedule） ScheduleFragment {39f1839＃0 id = 0x7f0d008b ...

这是相关的代码：

public class basic extends AppCompatActivity
        implements NavigationView.OnNavigationItemSelectedListener {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_basic);
        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);

        DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
        ActionBarDrawerToggle toggle = new ActionBarDrawerToggle(
            this, drawer, toolbar, R.string.navigation_drawer_open, R.string.navigation_drawer_close);
        drawer.setDrawerListener(toggle);
        toggle.syncState();

        NavigationView navigationView = (NavigationView) findViewById(R.id.nav_view);
        navigationView.setNavigationItemSelectedListener(this);
        displaySelectedScreen(R.id.nav_schedule);
    }

    @Override
    public void onBackPressed() {
        DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
        if (drawer.isDrawerOpen(GravityCompat.START)) {
            drawer.closeDrawer(GravityCompat.START);
        } else {
            super.onBackPressed();
        }
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.basic, 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.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }
public boolean onNavigationItemSelected(MenuItem item) {
        displaySelectedScreen(item.getItemId());
        return true;
    }
    private void displaySelectedScreen(int itemId) {
        Intent intent=null;
        switch (itemId) {
            case R.id.nav_schedule:
                intent=new Intent(this, ActivitySchedule.class);
                startActivity(intent);
                break;
        }

活动代码

package com.mygymroutine.mygymroutine.activities;


import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;


import com.mygymroutine.mygymroutine.Fragments.ScheduleFragment;
import com.mygymroutine.mygymroutine.R;


public class ActivitySchedule extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.acivity_schedule);
        if(savedInstanceState==null){
            ScheduleFragment fg = new ScheduleFragment();
            getSupportFragmentManager().beginTransaction().add(R.id.fragment_schedule, fg)
                    .commit();
        }
    }
}

片段

package com.mygymroutine.mygymroutine.Fragments;

import android.content.Intent;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.design.widget.FloatingActionButton;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import com.mygymroutine.mygymroutine.R;

public class ScheduleFragment extends Fragment {

    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        //returning our layout file
        //change R.layout.yourlayoutfilename for each of your fragments
        View rootView=inflater.inflate(R.layout.fragment_schedule, container, false);
        FloatingActionButton fab=(FloatingActionButton)rootView.findViewById(R.id.fab_schedule);
        return inflater.inflate(R.layout.fragment_schedule, container, false);
    }


    @Override
    public void onViewCreated(View view, @Nullable Bundle savedInstanceState) {
        super.onViewCreated(view, savedInstanceState);

        getActivity().setTitle("Schedule");
    }
}

片段计划xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/fragment_schedule"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <TextView
        android:id="@+id/textView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentTop="true"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="17dp"
        android:text="Schedule"
        android:textAppearance="?android:attr/textAppearanceLarge" />

    <android.support.design.widget.FloatingActionButton
        android:id="@+id/fab_schedule"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:layout_alignParentEnd="true"
        android:layout_alignParentRight="true"
        android:layout_marginBottom="41dp"
        android:layout_marginEnd="32dp"
        android:layout_marginRight="32dp"
        android:clickable="true"
        android:tint="@android:color/background_light"
        app:backgroundTint="@android:color/holo_red_light"
        app:fabSize="mini"
        app:rippleColor="@android:color/transparent"
        app:srcCompat="@android:drawable/ic_menu_add" />

</RelativeLayout>

活动时间表xml：

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout 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"
    tools:context="com.mygymroutine.mygymroutine.activities.ActivitySchedule">

</android.support.constraint.ConstraintLayout>

Answer 1

在。 onOptionsItemSelected方法添加以下内容（此方法带来一个参数 - MenuItem项）

switch (item.getItemId())
    case R.id.myFirst
        startActivity(new Intent(this, MyFirstActivity.class));
    case R.id.mySecond
        startActivity (newIntent(this, MySecondActivity.class));

等等。您可以使用必要的视图定义活动的布局。您也可以在清单文件中声明活动。

这很有效。我正在从主要开始我的活动。

Answer 2

下面：

getSupportFragmentManager().beginTransaction().add(R.id.fragment_schedule, fg)
                .commit();

您正在传递R.id.fragment_schedule作为片段的容器。片段将被插入的位置。但是，R.id.fragment_schedule是您Fragment的一部分。所以，它还没有膨胀。您不能将其用作容器，因为它尚未创建。

我想你想要的是：

<android.support.constraint.ConstraintLayout 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"
    tools:context="com.mygymroutine.mygymroutine.activities.ActivitySchedule"

   <!-- ADD LINE BELOW -->
    android:id="@+id/fragment_container" > 

</android.support.constraint.ConstraintLayout>

并改变这一点：

getSupportFragmentManager().beginTransaction().add(R.id.fragment_schedule, fg)
                .commit();

到此：

getSupportFragmentManager().beginTransaction().add(R.id.fragment_container, fg)
                .commit();

无法启动活动，找不到ID的视图

2 个答案: