java - 选中的复选框数

Question

我有 4 个复选框，我尝试在 TextView 上显示选中了多少个。
我创建了一个变量 numberOfTrue 并在开关中增加了它。当然，我的应用现在无法运行，textView 仍然显示“0”
更改点击框数后变量不刷新，我现在应该修复什么？
我不知道。

public class MainActivity extends AppCompatActivity implements CompoundButton.OnCheckedChangeListener {

    private int numberOfTrue = 0;
    private TextView tv1;
    private CheckBox cb1;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        CheckBox cb2,cb3,cb4;
        Button b2;


        b2 = (Button)findViewById(R.id.b2);

        tv1 = (TextView)findViewById(R.id.tv1);
        cb1 = (CheckBox)findViewById(R.id.cb1);
        cb1.setChecked(getFromSP("cb1"));
        cb1.setOnCheckedChangeListener(this);
        cb2 = (CheckBox)findViewById(R.id.cb2);
        cb2.setChecked(getFromSP("cb2"));
        cb2.setOnCheckedChangeListener(this);
        cb3 = (CheckBox)findViewById(R.id.cb3);
        cb3.setChecked(getFromSP("cb3"));
        cb3.setOnCheckedChangeListener(this);
        cb4 = (CheckBox)findViewById(R.id.cb4);
        cb4.setChecked(getFromSP("cb4"));
        cb4.setOnCheckedChangeListener(this);


        tv1.setText(""+numberOfTrue);


        b2.setOnClickListener(new View.OnClickListener() {

            public void onClick(View view) {

                finish();

            }
        });



    }


    private boolean getFromSP(String key){
        SharedPreferences preferences = getApplicationContext().getSharedPreferences("PROJECT_NAME", android.content.Context.MODE_PRIVATE);
        return preferences.getBoolean(key, false);
    }
    private void saveInSp(String key,boolean value) {
        SharedPreferences preferences = getApplicationContext().getSharedPreferences("PROJECT_NAME", android.content.Context.MODE_PRIVATE);
        SharedPreferences.Editor editor = preferences.edit();
        editor.putBoolean(key, value);
        editor.commit();
    }



    @Override
    public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {

        switch(buttonView.getId()){
            case R.id.cb1:
                saveInSp("cb1",isChecked);
                if (isChecked == true){
                    numberOfTrue++;
            }
                break;
            case R.id.cb2:
                saveInSp("cb2",isChecked);
                if (isChecked == true){
                    numberOfTrue++;
                }
                break;

            case R.id.cb3:
                saveInSp("cb3",isChecked);
                if (isChecked == true){
                    numberOfTrue++;
                }
                break;

            case R.id.cb4:
                saveInSp("cb4",isChecked);
                if (isChecked == true){
                    numberOfTrue++;
                }
                break;

        }
    }
}

Answer 1

1.) 按照answer here ，它表示将字符串与 TextView 一起使用喜欢tv1.setText(""+numberOfTrue);

2.) 添加tv1.setText(""+numberOfTrue);在 onCheckedChanged( 的末尾函数以反射(reflect)您的新值 textview在checkChange之后事件

    @Override
    public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
        // switch code
        tv1.setText(""+numberOfTrue); 
   }