R无法解决- Android错误

我刚刚下载并安装了新的Android SDK。我想创建一个简单的应用程序来测试它。

向导创建了以下代码:

package eu.mauriziopz.gps;

import android.app.Activity;
import android.os.Bundle;

public class ggps extends Activity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
    }
}

但是Eclipse给出了错误

R不能被分解

在网上

setContentView(R.layout.main);

Why?

PS:我在res/layout/下有一个名为main.xml的XML文件。

当前回答

So I have run into this problem multiple times when switching build targets. Usually doing a Project >> Clean worked for me. This last time, however, it did not. Finally I tried to open my default.properties file, located under the root project folder. I received an error message stating that it was out of sync with the file system. I actually deleted it and copied a coworkers version which allowed eclipse to rebuild my R file. I will paste what it looks like below. It is named 'default.properties'.

# This file is automatically generated by Android Tools.
# Do not modify this file -- YOUR CHANGES WILL BE ERASED!
# 
# This file must be checked in Version Control Systems.
# 
# To customize properties used by the Ant build system use,
# "build.properties", and override values to adapt the script to your
# project structure.

# Indicates whether an apk should be generated for each density.
split.density=false
# Project target.
target=android-3

2010-06-14 15:13:09

其他回答

首先查看你的生成文件，看它是否包含你的包名和R.java。如果它是空的，可能你没有权限创建新文件，所以退出eclipse，然后右键单击，以管理员身份运行，清理项目，一切都会正确。

否则你的XML文件中可能会有错误，或者检查其他答案。

2013-07-01 09:26:47

尝试使您的新XML布局文件名小写。例如，使用my_file.xml而不是myFile.xml。

2010-04-21 01:01:55

解决方案:

Eclipse重新启动后项目干净。它们是自动生成的，否则你是XML内部的任何组件(如按钮)后按Ctrl + Shift + o。它自动生成R文件，然后错误就解决了。

2012-06-25 07:48:01

关闭所有文件，清理项目，重新启动Eclipse。

2010-11-12 09:39:13