Java nullpointerexception错误我现在知道如何修复

错误在哪里？我怎样才能修好它？第24行中的布局为真错误

kaleciKayit.setOnClickListener(new View.OnClickListener() {

这是我所有的密码

public class oyuncuAdlariActivity extends AppCompatActivity {
Button kaleciKayit;
Button oyuncuKayit;
EditText isimGiris;
String isimGirisString;
int kaleciSayisi = 0;
@Override
protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_oyuncu_adlari);
    kaleciKayit = (Button) findViewById(R.id.kaleciButton);
    oyuncuKayit = (Button) findViewById(R.id.oyuncuButton);
    isimGiris = (EditText) findViewById(R.id.isimGir);
    kaleciKayit.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            kaleciSayisi++;
            isimGirisString = isimGiris.getText().toString();
            if (isimGirisString.isEmpty()){
                Toast toast1 = Toast.makeText(getApplicationContext(),getApplicationContext().getString(R.string.isimBos), Toast.LENGTH_SHORT);
                toast1.show();
            }
            else if (kaleciSayisi >2)
                kaleciKayit.setEnabled(false);
        }
    });
}

---

}首先，我建议将类中的对象设置为private。我认为问题在于，您可能分配了错误小部件的id？再次检查FindViewByID

我能想到的其他3种可能性是——

问题出在第一个活动中（在这种情况下，我要求您在这里发布第一个活动的内容）

setContentView方法指向错误的XML文件

您的AVD内存不足，需要在AVD管理器工具中添加更多内容

---

将MainActivity更改为此

public class MainActivity extends AppCompatActivity {


Button devamButton;
EditText takim1, takim2;
String takimTextA;
String takimTextB;
    @Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    devamButton = findViewById(R.id.devamButton);
    takim1 = findViewById(R.id.takimB);
    takim2 = findViewById(R.id.takimA);
    devamButton.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            takimTextA = takim1.getText().toString();
            takimTextB = takim2.getText().toString();
            if (takimTextA.equals(takimTextB)) {
                Toast toast1 = Toast.makeText(getApplicationContext(),getApplicationContext().getString(takimAyniOlmaz), Toast.LENGTH_SHORT);
                toast1.show();
            } else if (takimTextA.isEmpty() || takimTextB.isEmpty()) {
                Toast toast2 = Toast.makeText(getApplicationContext(), getApplicationContext().getString(R.string.takimBosBirakma), Toast.LENGTH_SHORT);
                toast2.show();
            } else {
                activityGecis1(v);
            }
        }
    });
}
private void activityGecis1(View v) {
       Intent gecis1 = new Intent(v.getContext(), oyuncuAdlariActivity.class);
     startActivity(gecis1);
}

---

由于您正在onclicklistener内部调用，可能这是指向该函数类的意图。

谢谢，我会尝试。我找不到问题和解决方案，但添加了第一个活动代码。当活动为空时，我添加的ram和存储内存仍然相同。没有错误