我正在尝试让一个按钮将其值与其他变量进行比较。在 onClick 方法中,我收到一个错误,指出变量在内部类中被访问,需要声明为 final。问题是变量应该被改变,所以我不能让它成为最终的。我该如何解决这个问题?这是我的代码:
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
public class GameActivity extends Activity implements View.OnClickListener {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_game);
int partA = 9;
int partB = 9;
int correctAnswer = partA * partB;
int wrongAnswer1 = correctAnswer++;
int wrongAnswer2 = correctAnswer--;
TextView textObjectA = (TextView)findViewById(R.id.textPartA);
TextView textObjectB = (TextView)findViewById(R.id.textPartB);
Button buttonObjectChoice1 = (Button)findViewById(R.id.buttonChoice1);
Button buttonObjectChoice2 = (Button)findViewById(R.id.buttonChoice2);
Button buttonObjectChoice3 = (Button)findViewById(R.id.buttonChoice3);
buttonObjectChoice1.setText("" + correctAnswer);
buttonObjectChoice2.setText("" + wrongAnswer1);
buttonObjectChoice3.setText("" + wrongAnswer2);
buttonObjectChoice1.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
int answerGiven = Integer.parseInt("" + buttonObjectChoice1.getText());
if(correctAnswer==answerGiven) {
}
}
});
buttonObjectChoice1.setOnClickListener(this);
buttonObjectChoice1.setOnClickListener(this);
}
public void onClick(View view) {}
}
两种方法:
-
制作
buttonObjectChoice1
final
:@Override protected void onCreate(Bundle savedInstanceState) { ... final Button buttonObjectChoice1 =(Button)findViewById(R.id.buttonChoice1); ... buttonObjectChoice1.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { int answerGiven = Integer.parseInt("" + buttonObjectChoice1.getText()); ... } }); }
-
在运行时转换视图:
buttonObjectChoice1.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { final Button btn = (Button)v; int answerGiven = Integer.parseInt("" + btn.getText()); ... } });
方法2的优点是,它将减少编译器生成访问器方法来访问buttonObjectChoice1对象的工作量。
尝试将变量声明为类的私有字段,并在方法中相应地更新它。