Question

我刚开始构建＆＃34; SIMPLE CALCULATOR＆＃34;与＆＃34;两个JAVA CLASSES＆＃34;一个是MainActivity，另一个是显示答案。

我的代码中没有任何错误，但是当我运行应用时，按钮无法点击。我这样做了3个小时仍然无法正常工作。

public class MainActivity extends Activity {
 public static String SUM_DISPLAY ="com.example.calculatorrm.DISPLAY";
 @Override
 protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    Button listener = (Button)findViewById(R.id.add);
    final Intent intent =new Intent (this,DisplayAnswerActivity.class);
    listener.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View arg0) {
            // TODO Auto-generated method stub  
            EditText e1 = (EditText)findViewById(R.id.fistvalue);
            EditText e2 = (EditText)findViewById(R.id.secondvalue);

            // For displaying answer 
            int firstvalue =Integer.parseInt(e1.getText().toString());
            int secondvalue = Integer.parseInt(e2.getText().toString());    
            int sum = firstvalue + secondvalue; 
            String display = Integer.toString(sum);
            intent.putExtra(SUM_DISPLAY,display);
        }
    });
}

Answer 1

此行之后调用startActivity方法：

intent.putExtra(SUM_DISPLAY,display);

像这样：

startActivity(intent);

Answer 2

public class MainActivity extends Activity {
 Context context;
 @Override
 protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    context = this;
    Button listener = (Button)findViewById(R.id.add);

    listener.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View arg0) {
            // TODO Auto-generated method stub  
            EditText e1 = (EditText)findViewById(R.id.fistvalue);
            EditText e2 = (EditText)findViewById(R.id.secondvalue);

            // For displaying answer 
            int firstvalue =Integer.parseInt(e1.getText().toString());
            int secondvalue = Integer.parseInt(e2.getText().toString());    
            int sum = firstvalue + secondvalue; 
            String display = Integer.toString(sum);
            Intent intent =new Intent (context, DisplayAnswerActivity.class);
            intent.putExtra("Sum",display);
            startActivity(intent);
        }
    });
}

在活动DisplayAnswerActivity中获取Intent，即可在onCreateMethod()中获得此总和值。

Intent i = getIntent();
String output = i.getStringExtra("Sum");

按钮不是可点击的android

2 个答案: