Question

我一直在下面的代码中遇到错误，特别是星号包围的两个部分（R.id.action_settings和fragment_display_message），

package com.example.completelypointlessapp;

import android.app.Fragment;
import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.ActionBarActivity;
import android.view.LayoutInflater;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;

public class DisplayMessageActivity extends ActionBarActivity {

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        // Get the message from the intent
        Intent intent = getIntent();
        String message = intent.getStringExtra(MainActivity.EXTRA_MESSAGE);

        // Create the text view
        TextView textView = new TextView(this);
        textView.setTextSize(40);
        textView.setText(message);

        // Set the text view as the activity layout
        setContentView(textView);
    }

    @Override
    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);
    }

    /**
     * A placeholder fragment containing a simple view.
     */
    public static class PlaceholderFragment extends Fragment {

        public PlaceholderFragment() { }

        @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container,
              Bundle savedInstanceState) {
              View rootView = inflater.inflate(R.layout.**fragment_display_message,**
                      container, false);
              return rootView;
        }
    }
}

错误状态：＆＃34; fragment_display_message cannot be resolved or is not a field" and "action_settings cannot be resolved or is not a field＆＃34;

有人可以帮忙解决这个问题吗？（对于某些不正确的格式的道歉，我是这个网站的新手）

Answer 1

View rootView = inflater.inflate(R.layout.fragment_display_message,
                      container, false);

您有fragment_display_message.xml布局文件吗？

if (id == R.id.action_settings)

您是否拥有ActionBar的自定义菜单文件？

示例 -

<menu xmlns:android="http://schemas.android.com/apk/res/android" >
    <item
        android:id="@+id/action_settings"
        android:title="Settings"
        android:showAsAction="never"
        >
    </item>

</menu>

如果两者的答案都是NO，则错误很明显。

创建的活动中的错误帮助（android）

1 个答案: