Question

package com.example.android.home;

import android.app.Activity;
import android.os.Bundle;
import android.widget.*;
import android.view.*;
public class HomeActivity extends Activity {
    /** Called when the activity is first created. */
  private EditText input;
  private EditText result;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        input = (EditText) findById(R.id.input1);
        result = (EditText) ***findById***(R.id.result); //Error:Undefined for the type HomeActivity

        input.addKeyListener(new View.OnKeyListener() {   Error: Undefined for the type EditText
            public boolean onKey(View v, int keycode, KeyEvent keyevent) {      
                if (keyevent.getAction() == KeyEvent.ACTION_UP) {            
                    doCalculation();      
                    }          
                return false;       
                }    
            }); 
            }
     private void doCalculation()
     {
             String strValue = input.getText().toString();
             int resultt = Integer.parseInt(strValue) * 2;
             result.setText("Result: "+ resultt);  

     }

}

Answer 1

正如@Varun所说，没有findById()方法。您可能正在考虑findViewById()。

您可以通过检查任何示例Android活动并查看它如何访问小部件来自行找到此信息。 SDK安装中有许多示例活动，还有在线。

帮助我解决此错误

1 个答案: