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
关闭所有文件，清理项目，重新启动Eclipse。
or
R是一个自动生成的类，它包含用于标识资源的常量。如果你没有R.java文件(在Eclipse的1.5 SDK中是gen/eu.mauriziopz.gps/R.java)，我建议关闭并重新打开你的项目，或者转到project > Build all(并选择“自动构建”，而Josef则推荐)。如果这行不通，那就试着做一个新项目
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
对我来说有用的是安装“Android SDK Build-tools”。打开Android SDK管理器，安装Android SDK构建工具。它还帮助更新了Eclipse中的android开发平台:帮助>检查更新
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。
我的R文件消失了，不会生成-控制台报告了这个:
[2010-09-22 16:19:40 - myproject] res\ draw- ldpi\downloadNow.png:无效的文件名:必须只包含[a-z0-9_.]
因此，资源名称不能有大写字母-确认它们都是小写字母并包含。而且只有_
我遇到了同样的问题，但找不到哪个xml文件导致了错误。
多亏了这篇文章，我安装了18.1.1而不是19的构建工具，它显示了有缺陷的文件。看起来版本19并没有显示实际的错误。
希望它能帮助到一些人:-)
