android - 微调器:AppCompatSpinner 无法转换为 com.example.....MySpinner (Android)

Question

我正在尝试从微调器中选择的相同项目触发事件。我发现了一个名为 MySpinner 的类，它扩展了 Spinner，但显然我在实现它时遇到了问题。

   package com.example.ilija.festivalapp_makedox;

import android.content.Intent;
import android.content.res.Resources;
import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.NavigationView;
import android.support.design.widget.Snackbar;
import android.support.v4.view.GravityCompat;
import android.support.v4.widget.DrawerLayout;
import android.support.v7.app.ActionBarDrawerToggle;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.util.Log;
import android.view.MenuItem;
import android.view.View;
import android.widget.AdapterView;
import android.widget.Spinner;
import android.widget.TextView;
import android.widget.Toast;
import com.example.ilija.festivalapp_makedox.MySpinner;

import com.example.ilija.festivalapp_makedox.agendacalendarview.CalendarPickerController;

import java.util.ArrayList;

public class CustomSpinner extends AppCompatActivity implements NavigationView.OnNavigationItemSelectedListener {

    public ArrayList<SpinnerModel> CustomListViewValuesArr=new ArrayList<>();
    public ArrayList<SpinnerModel> CustomListViewValuesArr1=new ArrayList<>();
    public ArrayList<SpinnerModel> CustomListViewValuesArr2=new ArrayList<>();
    public ArrayList<SpinnerModel> CustomListViewValuesArr3=new ArrayList<>();

    public ArrayList<SpinnerModel> CustomListViewValuesArrTest=new ArrayList<>();
    /*public ArrayList<SpinnerModel> CustomListViewValuesArr1Test=new ArrayList<>();
    public ArrayList<SpinnerModel> CustomListViewValuesArr2Test=new ArrayList<>();
    public ArrayList<SpinnerModel> CustomListViewValuesArr3Test=new ArrayList<>();*/

    TextView output = null;
    CustomSpinner activity = null;
    NavigationView navigationView;
    CustomAdapter adapter,adapter1,adapter2,adapter3,adapterTest,adapter1Test,adapter2Test,adapter3Test;
    int i=0;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_custom_spinner);
        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        toolbar.setTitle("Movies");
        setSupportActionBar(toolbar);
        activity = this;
        Spinner SpinnerExample = (Spinner) findViewById(R.id.spinner);
        Spinner SpinnerExample1 = (Spinner) findViewById(R.id.spinner1);
        Spinner SpinnerExample2 = (Spinner) findViewById(R.id.spinner2);
        Spinner SpinnerExample3 = (Spinner) findViewById(R.id.spinner3);
        MySpinner SpinnerExampleTest = (MySpinner) findViewById(R.id.spinnerTest);
  /*      Spinner SpinnerExampleTest = (Spinner) findViewById(R.id.spinnerTest);
        Spinner SpinnerExampleTest1 = (Spinner) findViewById(R.id.spinner1Test);
        Spinner SpinnerExampleTest2 = (Spinner) findViewById(R.id.spinner2Test);
        Spinner SpinnerExampleTest3 = (Spinner) findViewById(R.id.spinner3Test);*/
        output = (TextView)findViewById(R.id.output);

        setListData();
        setListData1();
        setListData2();
        setListData3();

        setListDataTest();
       /* setListData1Test();
        setListData2Test();
        setListData3Test();*/

        Resources res = getResources();
        adapter = new CustomAdapter(activity,R.layout.spinner_rows,CustomListViewValuesArr,res);
        adapter1 = new CustomAdapter(activity,R.layout.spinner_rows,CustomListViewValuesArr1,res);
        adapter2 = new CustomAdapter(activity,R.layout.spinner_rows,CustomListViewValuesArr2,res);
        adapter3 = new CustomAdapter(activity,R.layout.spinner_rows,CustomListViewValuesArr3,res);

       adapterTest = new CustomAdapter(activity,R.layout.spinner_rows,CustomListViewValuesArrTest,res);
    /*     adapter1Test = new CustomAdapter(activity,R.layout.spinner_rows,CustomListViewValuesArr1Test,res);
        adapter2Test = new CustomAdapter(activity,R.layout.spinner_rows,CustomListViewValuesArr2Test,res);
        adapter3Test = new CustomAdapter(activity,R.layout.spinner_rows,CustomListViewValuesArr3Test,res);*/


        SpinnerExample.setAdapter(adapter);

        SpinnerExample.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
            @Override
            public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
                i++;  //Avoid fist time oppening the OnClick start new intent. First time is for set pic of the first element in the list.
                String Movie = ((TextView) view.findViewById(R.id.movieName)).getText().toString();
                if(i>1){
                    Intent intent = new Intent(CustomSpinner.this, MovieTrailer.class);

                    startActivity(intent);
                }
            }

            @Override
            public void onNothingSelected(AdapterView<?> parent) {

            }
        });

       SpinnerExample1.setAdapter(adapter1);
        SpinnerExample1.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
            @Override
            public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
                i++;  //Avoid fist time oppening the OnClick start new intent. First time is for set pic of the first element in the list.
                String Movie = ((TextView) view.findViewById(R.id.movieName)).getText().toString();
                if(i>2){
                    Intent intent = new Intent(CustomSpinner.this, MovieTrailer.class);

                    startActivity(intent);
                }
            }

            @Override
            public void onNothingSelected(AdapterView<?> parent) {

            }
        });



        SpinnerExample2.setAdapter(adapter2);
        SpinnerExample2.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
            @Override
            public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
                Toast.makeText(getApplicationContext(), "HERE" , Toast.LENGTH_SHORT).show();
                i++;  //Avoid fist time oppening the OnClick start new intent. First time is for set pic of the first element in the list.
                String Movie = ((TextView) view.findViewById(R.id.movieName)).getText().toString();
                if(i>3){
                    Intent intent = new Intent(CustomSpinner.this, MovieTrailer.class);

                    startActivity(intent);
                }
            }
            @Override
            public void onNothingSelected(AdapterView arg0) {
                Toast.makeText(getApplicationContext(), (CharSequence) "HERE AGAIN", Toast.LENGTH_SHORT).show();
            }
        });


        SpinnerExample3.setAdapter(adapter3);
        SpinnerExample3.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
            @Override
            public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
                i++;  //Avoid fist time oppening the OnClick start new intent. First time is for set pic of the first element in the list.
                String Movie = ((TextView) view.findViewById(R.id.movieName)).getText().toString();
                if(i>4){
                    Intent intent = new Intent(CustomSpinner.this, MovieTrailer.class);

                    startActivity(intent);
                }
            }

            @Override
            public void onNothingSelected(AdapterView<?> parent) {

            }
        });

        //********************************************************TEST COMPONENTS******************************************************************//


        SpinnerExampleTest.setAdapter(adapterTest);

        SpinnerExampleTest.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
            @Override
            public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
                Toast.makeText(getApplicationContext(), (CharSequence) "HERE", Toast.LENGTH_SHORT).show();
                String Movie = ((TextView) view.findViewById(R.id.movieName)).getText().toString();

            }

            @Override
            public void onNothingSelected(AdapterView<?> parent) {
                Toast.makeText(getApplicationContext(), (CharSequence) "HERE AGAIN", Toast.LENGTH_SHORT).show();
            }
        });

      /*  SpinnerExampleTest1.setAdapter(adapter1Test);
        SpinnerExampleTest1.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
            @Override
            public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
                String Movie = ((TextView) view.findViewById(R.id.movieName)).getText().toString();

            }

            @Override
            public void onNothingSelected(AdapterView<?> parent) {

            }
        });

        SpinnerExampleTest2.setAdapter(adapter2Test);
        SpinnerExampleTest2.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
            @Override
            public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
                String Movie = ((TextView) view.findViewById(R.id.movieName)).getText().toString();

            }

            @Override
            public void onNothingSelected(AdapterView<?> parent) {

            }
        });


        SpinnerExampleTest3.setAdapter(adapter3Test);
        SpinnerExampleTest3.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
            @Override
            public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
                String Movie = ((TextView) view.findViewById(R.id.movieName)).getText().toString();

            }

            @Override
            public void onNothingSelected(AdapterView<?> parent) {

            }
        });
*/


        //**************************************************TEST COMPONENTS**************************************************************************************//


        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) findViewById(R.id.nav_view);

        navigationView.setNavigationItemSelectedListener(this);

        FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
      /*  fab.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
                        .setAction("Action", null).show();
            }
        });*/
    }


    public void setListData(){
        String moy[] = {"DEN UNGE ZLATAN/BECOMING ZLATAN","THE SWEDISH THEORY OF LOVE","JONAS E O CIRCO SEM LONA/JONAS AND THE BACKYARD CIRCUS","ZID SMRTI, I TAKO TO/WALL OF DEATH, AND ALL",
                "ПОСЛАННИКИ БОЛЬШОЙ ЗЕМЛИ/ SIBERIAN FLOATING HOSPITAL","FIGURA/FIGURE","1","2","3","1","2","3"};
        for(int i=0;i<moy.length;i++){

            final SpinnerModel sched = new SpinnerModel();
            sched.setMovieName(moy[i]);
            sched.setImage("image1"+i);
            CustomListViewValuesArr.add(sched);


        }
    }

    public void setListData1(){
        String moy1[] = {"EL BOTÓN DE NÁCAR/PEARL","BRØDRE/BROTHERS 2015 110’","V LUCHAKH SOLNCA/UNDER THE SUN","KANTON JUGOSLAWIEN/LITTLE YUGOSLAVIA","1","2","3","1","2","3","1","2","3","1","2","3"};
        for(int i=0;i<moy1.length;i++){

            final SpinnerModel sched1 = new SpinnerModel();
            sched1.setMovieName(moy1[i]);
            sched1.setImage("image2"+i);


            CustomListViewValuesArr1.add(sched1);


        }
    }

    public void setListData2(){
        String moy2[] = {"JUST ANOTHER DAY IN EGYPT","THE PERFECT CIRCLE","MOJ NAROBE SVET/MY WORLD IS UPSIDE DOWN","1","2","3","1","2","3","1","2","3","1","2","3"};
        for(int i=0;i<moy2.length;i++){

            final SpinnerModel sched2 = new SpinnerModel();
            sched2.setMovieName(moy2[i]);
            sched2.setImage("image3"+i);
            CustomListViewValuesArr2.add(sched2);


        }
    }

    public void setListData3(){
        String moy3[] = {"BREZMEJNO/BEYOND BOUNDARIES","SOMETHING ABOUT LIFE","NA KRAYU/ON THE EDGE","JAMEY’S GEVECHT/JAMEY’S FIGHT","SCHWERELOS/ZERO-G"};
        for(int i=0;i<moy3.length;i++){

            final SpinnerModel sched3 = new SpinnerModel();
            sched3.setMovieName(moy3[i]);
            sched3.setImage("image4"+i);
            CustomListViewValuesArr3.add(sched3);


        }
    }

    //**************************************************TEST COMPONENTS**************************************************************************************//


    public void setListDataTest(){
        String moyTest[] = {"MovieTest1","MovieTest2","MovieTest2"};
        for(int i=0;i<moyTest.length;i++){

            final SpinnerModel schedTest = new SpinnerModel();
            schedTest.setMovieName(moyTest[i]);
            schedTest.setImage("image"+i);

            CustomListViewValuesArrTest.add(schedTest);


        }
    }

   /* public void setListData1Test(){
        String moy1Test[] = {"MovieTest1","MovieTest1","Movie1","Movie1"};
        for(int i=0;i<moy1Test.length;i++){

            final SpinnerModel sched1Test = new SpinnerModel();
            sched1Test.setMovieName(moy1Test[i]);
            sched1Test.setImage("image"+i);


            CustomListViewValuesArr1Test.add(sched1Test);


        }
    }

    public void setListData2Test(){
        String moy2Test[] = {"MovieTest1","MovieTest2","Movie3"};
        for(int i=0;i<moy2Test.length;i++){

            final SpinnerModel sched2Test = new SpinnerModel();
            sched2Test.setMovieName(moy2Test[i]);
            sched2Test.setImage("image"+i);
            CustomListViewValuesArr2Test.add(sched2Test);


        }
    }

    public void setListData3Test(){
        String moy3Test[] = {"Movie1","Movie2","Movie3"};
        for(int i=0;i<moy3Test.length;i++){

            final SpinnerModel sched3Test = new SpinnerModel();
            sched3Test.setMovieName(moy3Test[i]);
            sched3Test.setImage("image"+i);
            CustomListViewValuesArr3Test.add(sched3Test);


        }
    }

*/

    //**************************************************TEST COMPONENTS**************************************************************************************//



    @SuppressWarnings("StatementWithEmptyBody")
    @Override
    public boolean onNavigationItemSelected(MenuItem item) {
        // Handle navigation view item clicks here.
        int id = item.getItemId();

        if (id == R.id.nav_camara) {
            Intent intent = new Intent(CustomSpinner.this, MainScreen.class);
            startActivity(intent);
            Toast.makeText(getBaseContext(), "Program", Toast.LENGTH_LONG).show();
            //Set the fragment initially
            // Handle the camera action
        } else if (id == R.id.nav_gallery) {
            Intent i = new Intent(CustomSpinner.this, CustomSpinner.class);
            startActivity(i);
            Toast.makeText(getBaseContext(), "Movies", Toast.LENGTH_LONG).show();


        } else if (id == R.id.nav_slideshow) {
            Intent intent = new Intent(CustomSpinner.this, BasicActivity.class);
            startActivity(intent);
            Toast.makeText(getBaseContext(), "Timeline", Toast.LENGTH_LONG).show();


        } else if (id == R.id.nav_manage) {

        } else if (id == R.id.nav_share) {
            //Intent intent = new Intent(MainScreen.this, MapsActivity.class);
            // startActivity(intent);
            // Toast.makeText(getBaseContext(), "Maps", Toast.LENGTH_LONG).show();

        } else if (id == R.id.nav_send) {

        }

        DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
        drawer.closeDrawer(GravityCompat.START);
        return true;
    }
}

MySpinner 类包含此代码:

public class MySpinner extends Spinner {
    OnItemSelectedListener listener;

public MySpinner(Context context, AttributeSet attrs) {
    super(context, attrs);
}

@Override
public void setSelection(int position) {
    super.setSelection(position);
    if (listener != null)
        listener.onItemSelected(null, null, position, 0);
}

public void setOnItemSelectedEvenIfUnchangedListener(
        AdapterView.OnItemSelectedListener listener) {
    this.listener = listener;
}

打开此 Activity 时出现此错误，应用程序崩溃。

/com.example.ilija.festivalapp_makedox E/AndroidRuntime: FATAL EXCEPTION: main
                                                                                   Process: com.example.ilija.festivalapp_makedox, PID: 12914
                                                                                   java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.ilija.festivalapp_makedox/com.example.ilija.festivalapp_makedox.CustomSpinner}: java.lang.ClassCastException: android.support.v7.widget.AppCompatSpinner cannot be cast to com.example.ilija.festivalapp_makedox.MySpinner
                                                                                       at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2596)
                                                                                       at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2653)
                                                                                       at android.app.ActivityThread.access$800(ActivityThread.java:156)
                                                                                       at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1355)
                                                                                       at android.os.Handler.dispatchMessage(Handler.java:102)
                                                                                       at android.os.Looper.loop(Looper.java:157)
                                                                                       at android.app.ActivityThread.main(ActivityThread.java:5872)
                                                                                       at java.lang.reflect.Method.invokeNative(Native Method)
                                                                                       at java.lang.reflect.Method.invoke(Method.java:515)
                                                                                       at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:858)
                                                                                       at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:674)
                                                                                       at dalvik.system.NativeStart.main(Native Method)
                                                                                    Caused by: java.lang.ClassCastException: android.support.v7.widget.AppCompatSpinner cannot be cast to com.example.ilija.festivalapp_makedox.MySpinner
                                                                                       at com.example.ilija.festivalapp_makedox.CustomSpinner.onCreate(CustomSpinner.java:56)
                                                                                       at android.app.Activity.performCreate(Activity.java:5312)
                                                                                       at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1111)
                                                                                       at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2552)
                                                                                       at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2653) 
                                                                                       at android.app.ActivityThread.access$800(ActivityThread.java:156) 
                                                                                       at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1355) 
                                                                                       at android.os.Handler.dispatchMessage(Handler.java:102) 
                                                                                       at android.os.Looper.loop(Looper.java:157) 
                                                                                       at android.app.ActivityThread.main(ActivityThread.java:5872) 
                                                                                       at java.lang.reflect.Method.invokeNative(Native Method) 
                                                                                       at java.lang.reflect.Method.invoke(Method.java:515) 
                                                                                       at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:858) 
                                                                                       at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:674) 
                                                                                       at dalvik.system.NativeStart.main(Native Method) 

Answer 1

我猜 layout.activity_custom_spinner.xml 是这样的:

  <Spinner id="@+id/spinnerTest" ...>

应该是这样的:

  <MySpinner id="@+id/spinnerTest" ...>

MySpinner 可以扩展 android.support.v7.widget.AppCompatSpinner。

https://developer.android.com/reference/android/support/v7/widget/AppCompatSpinner.html

This will automatically be used when you use Spinner in your layouts. You should only need to manually use this class when writing custom views.