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

重启你的项目

文件>>invalidate缓存/重启

注意:

Android会自动创建一个不需要导入的。r文件 进口android.R。* << R.java文件由android Studio自动创建 Android工作室有很多缓存,这就是为什么有时会发生这种情况

其他回答

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

重新启动计算机。 除了这种方法,什么也帮不了我

我也有这个问题。结果发现我无意中从strings.xml文件中删除了“app_name”字符串资源,这导致了一个无声错误。一旦我重新添加了它,R类就成功生成了,一切都恢复并运行了。

删除main.out.xml。我是新手,还不知道这个文件是用来做什么的,但删除它解决了这个问题。

重启你的项目

文件>>invalidate缓存/重启

注意:

Android会自动创建一个不需要导入的。r文件 进口android.R。* << R.java文件由android Studio自动创建 Android工作室有很多缓存,这就是为什么有时会发生这种情况