Question

如您所见，我已导入R.java类，其中包含activity_main。但是setContent方法无法找到它。这是R.java类的定义：

/* AUTO-GENERATED FILE.  DO NOT MODIFY.
 *
 * This class was automatically generated by the
 * aapt tool from the resource data it found.  It
 * should not be modified by hand.
 */

package com.example.app2;

    public final class R {
    public static final class attr {
    }
    public static final class dimen {
        /**  Default screen margins, per the Android Design guidelines. 

         Customize dimensions originally defined in res/values/dimens.xml (such as
         screen margins) for sw720dp devices (e.g. 10" tablets) in landscape here.

         */
        public static final int activity_horizontal_margin=0x7f040000;
        public static final int activity_vertical_margin=0x7f040001;
    }
    public static final class drawable {
        public static final int ic_launcher=0x7f020000;
    }
    public static final class id {
        public static final int action_settings=0x7f080002;
        public static final int button1=0x7f080000;
        public static final int button2=0x7f080001;
    }
    public static final class layout {
        public static final int activity_main=0x7f030000;
    }
    public static final class menu {
        public static final int main=0x7f070000;
    }
    public static final class string {
        public static final int action_settings=0x7f050001;
        public static final int app_name=0x7f050000;
        public static final int hello_world=0x7f050002;
    }
    public static final class style {
        /** 
        Base application theme, dependent on API level. This theme is replaced
        by AppBaseTheme from res/values-vXX/styles.xml on newer devices.


            Theme customizations available in newer API levels can go in
            res/values-vXX/styles.xml, while customizations related to
            backward-compatibility can go here.


        Base application theme for API 11+. This theme completely replaces
        AppBaseTheme from res/values/styles.xml on API 11+ devices.

     API 11 theme customizations can go here. 

        Base application theme for API 14+. This theme completely replaces
        AppBaseTheme from BOTH res/values/styles.xml and
        res/values-v11/styles.xml on API 14+ devices.

     API 14 theme customizations can go here. 
         */
        public static final int AppBaseTheme=0x7f060000;
        /**  Application theme. 
     All customizations that are NOT specific to a particular API-level can go     here. 
         */
        public static final int AppTheme=0x7f060001;
    }
}

这是我的MainActivity.java。你能告诉我为什么会出现这个错误吗？

package com.example.app2;

import android.R;
import android.app.Activity;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.widget.Button;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.Menu;


public class MainActivity extends Activity {
    Button button,bt1;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(android.R.layout.activity_main);//this line gives the error
        addListenerOnButton();
        addListnerOnButton2();
    }
public void addListenerOnButton() {

    button = (Button) findViewById(R.id.button1);

    button.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View arg0) {

          Intent browserIntent = 
                        new Intent(Intent.ACTION_VIEW, Uri.parse("http://www.ischelper.in"));
            startActivity(browserIntent);

        }
});


    }
public void addListnerOnButton2()
    {
        bt1=(Button) findViewById(R.id.button2);
        bt1.setOnClickListener(new OnClickListener(){

        @Override
        public void onClick(View arg0) {
            Intent browserIntent=new Intent(Intent.ACTION_VIEW, Uri.parse("http://www.ischelper.in/pages/lectures"));
            startActivity(browserIntent);
        }



    });
   }
}

Answer 1

替换此行：

import android.R;

......用这一行：

import com.example.app2.R;

代码说它无法找到activity_main但我在R.java中声明了它

1 个答案: