Question

我是Android编程的初学者。我尝试从Button启动一个Activity，但Eclipse返回错误'onOptionsItemsSelected is undefined for Object'。这是我的代码：

     package com.ipmedt4.challengeweek_v2;

     import android.support.v7.app.ActionBarActivity;
     import android.content.Intent;
     import android.os.Bundle;
     import android.view.Menu;
     import android.view.MenuItem;
     import android.view.View;
     import android.view.View.OnClickListener;
     import android.widget.Button;


    public class Loginscherm extends ActionBarActivity {
    Button aanmeldknop; 
    protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_loginscherm);
    Button aanmeldknop = (Button) findViewById(R.id.aanmeldknop); 
    aanmeldknop.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub
            Intent intent = new Intent(v.getContext(), Beginscherm.class); 
            startActivityForResult(intent, 0); 


}



public boolean onCreateOptionsMenu(Menu menu) {
   // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.loginscherm, menu);
    return true;
}

    public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int id = item.getItemId();
    if (id == R.id.action_settings) 
        return true;

    return super.onOptionsItemSelected(item);


}}}

此外，他最后返回了几个语法错误。希望您能够帮助我。

Answer 1

你错过了new View.OnClickListener()中的花括号。您的程序应如下所示，

package com.ipmedt4.challengeweek_v2; 

 import android.support.v7.app.ActionBarActivity; 
 import android.content.Intent;
 import android.os.Bundle;
 import android.view.Menu;
 import android.view.MenuItem;
 import android.view.View;
 import android.view.View.OnClickListener;
 import android.widget.Button;


public class Loginscherm extends ActionBarActivity { 
Button aanmeldknop; 
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_loginscherm);
Button aanmeldknop = (Button) findViewById(R.id.aanmeldknop); 
aanmeldknop.setOnClickListener(new View.OnClickListener() {

    @Override 
    public void onClick(View v) {
        // TODO Auto-generated method stub 
        Intent intent = new Intent(v.getContext(), Beginscherm.class); 
        startActivityForResult(intent, 0); 
    }
}); 



public boolean onCreateOptionsMenu(Menu menu) {
   // Inflate the menu; this adds items to the action bar if it is present. 
   getMenuInflater().inflate(R.menu.loginscherm, menu);
   return true; 
 } 

public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will 
// automatically handle clicks on the Home/Up button, so long 
// as you specify a parent activity in AndroidManifest.xml. 
int id = item.getItemId();
if (id == R.id.action_settings) 
    return true; 

return super.onOptionsItemSelected(item);


 }

}

对于Object类型，onOptionsItemSelected方法未定义

1 个答案: