我的微调器 onClickListener 不起作用？

Question

我正在尝试创建一个下拉菜单，将文本视图的文本更改为“已选择的玩家：”，然后从下拉菜单中选择一个玩家。但是，当我在 android 上测试应用程序时，我可以单击一个微调器项目，但它没有注册任何内容。 textview 没有改变，也没有记录任何东西，就好像它根本没有注册点击监听器一样。这是我的代码

package com.example.buddyfizzturtles.stattracker;

import android.app.Dialog;
import android.content.DialogInterface;
import android.support.v7.app.AlertDialog;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Spinner;
import android.widget.TextView;
import android.widget.Toast;
import java.util.*;
import android.widget.AdapterView.OnItemSelectedListener;



public class MainActivity extends AppCompatActivity {
    EditText input;
    Button showBtn;
    TextView showPlayer;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        final Players p = new Players();
        // Pop-Up Dialog
        AlertDialog.Builder builder = new AlertDialog.Builder(this);
        builder.setTitle("Enter Name");
        builder.setIcon(R.drawable.basketball);
        builder.setMessage("Enter a name for your player");

        input = new EditText(this);
        builder.setView(input);

        //Set Positive Button
        builder.setPositiveButton("Ok", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {
                String text = input.getText().toString();
                Player x = new Player(text);
                p.addPlayer(x);
                Toast.makeText(MainActivity.this, "Added " + text + " to your player list", Toast.LENGTH_SHORT).show();

            }
        });

        //Set Negative Button
        builder.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {
                dialog.dismiss();

            }
        });

        //Create Builder
        final AlertDialog ad = builder.create();

        //Button
        showBtn = (Button) findViewById(R.id.addPlayerButton);
        showBtn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                ad.show();
            }
        });

        //Spinner Items
        Spinner dropNames = (Spinner) findViewById(R.id.choosePlayer);
        dropNames.setOnItemSelectedListener(new OnItemSelectedListener() {
            @Override
            public void onItemSelected(AdapterView<?> parentView, View selectedItemView, int position, long id) {
                Log.d("CLICKED:", "Successful Click");
                showPlayer = (TextView) findViewById(R.id.showPlayer);
                showPlayer.setText("Player Selected: " + );

            }

            @Override
            public void onNothingSelected(AdapterView<?> parentView) {
                // your code here
            }

        });

        ArrayAdapter<Player> adapter = new ArrayAdapter<Player>(this, android.R.layout.simple_spinner_item, p.returnList());
        adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        dropNames.setAdapter(adapter);


    }
}

Answer 1

你可以试试这个。看看能不能解决

Spinner spinner=(Spinner)findViewById(R.id.spinner);
spinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
    @Override
    public void onItemSelected(AdapterView<?> adapterView, View view, int i, long l) {
        Log.d("CLICKED:", "Successful Click");
        showPlayer = (TextView) findViewById(R.id.showPlayer);
        showPlayer.setText("Player Selected: " + );
    }

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

    }
});

希望对你有帮助

Answer 2

如果微调器正在加载数据，那么我认为这会对您有所帮助（最好在侦听器之外定义 showPlayer）。

 Spinner dropNames = (Spinner) findViewById(R.id.choosePlayer); 
 TextView showPlayer = (TextView) findViewById(R.id.showPlayer);

            dropNames.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
                                @Override
                                public void onItemSelected(
                                        AdapterView<?> parent, View view, int position, long id) {

                                        showPlayer.setText("Player Selected: " + String.valueOf(dropNames.getSelectedItem());
                                }
                                @Override
                                public void onNothingSelected(AdapterView<?> parent)
                                {

                                }
                            });