我遇到的问题是我的 MainActivity 中的 onCreate() 方法似乎无法启动另一个 Activity 。
我的代码可以正常工作,这样当我单击一个按钮时,我的“AboutActivity”就会启动。但是,我想让它在 MainActivity 中的 onCreate() 完成后立即启动“AboutActivity”。
当我尝试从 onCreate() 启动“AboutActivity”时运行该程序时,该程序陷入空白屏幕。
发布的代码是问题的简化版本。本质上,这就是我想要做的。
public class MainActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// Fire the intent that launches the "About" screen.
Intent aboutScreen = new Intent(getBaseContext(), AboutActivity.class);
this.startActivity(aboutScreen);
}
AboutActivity 类的代码:
public class AboutActivity extends MainActivity {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_about);
}
@Override
public void onPause() {
super.onPause();
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
return super.onCreateOptionsMenu(menu);
}
}
LogCat 消息是:
11-16 16:33:47.335: D/dalvikvm(1702): GC_FOR_ALLOC freed 65K, 7% free 2692K/2876K, paused 70ms, total 72ms
11-16 16:33:47.335: I/dalvikvm-heap(1702): Grow heap (frag case) to 3.347MB for 635812-byte allocation
11-16 16:33:47.435: D/dalvikvm(1702): GC_FOR_ALLOC freed 2K, 6% free 3310K/3500K, paused 98ms, total 98ms
11-16 16:33:47.715: D/dalvikvm(1702): GC_FOR_ALLOC freed 20K, 4% free 3469K/3608K, paused 28ms, total 29ms
11-16 16:33:47.735: I/dalvikvm-heap(1702): Grow heap (frag case) to 5.478MB for 2073616-byte allocation
11-16 16:33:47.845: D/dalvikvm(1702): GC_FOR_ALLOC freed 1K, 3% free 5493K/5636K, paused 112ms, total 112ms
11-16 16:33:48.175: I/Choreographer(1702): Skipped 36 frames! The application may be doing too much work on its main thread.
11-16 16:33:48.465: D/libEGL(1702): loaded /system/lib/egl/libEGL_emulation.so
11-16 16:33:48.555: D/(1702): HostConnection::get() New Host Connection established 0x2a210280, tid 1702
11-16 16:33:48.604: D/libEGL(1702): loaded /system/lib/egl/libGLESv1_CM_emulation.so
11-16 16:33:48.615: D/libEGL(1702): loaded /system/lib/egl/libGLESv2_emulation.so
11-16 16:33:48.715: W/EGL_emulation(1702): eglSurfaceAttrib not implemented
11-16 16:33:48.725: D/OpenGLRenderer(1702): Enabling debug mode 0
11-16 16:33:51.794: D/dalvikvm(1702): GC_FOR_ALLOC freed 139K, 4% free 6352K/6608K, paused 38ms, total 46ms
11-16 16:33:53.135: D/dalvikvm(1702): GREF has increased to 201
11-16 16:33:55.315: D/dalvikvm(1702): GC_FOR_ALLOC freed 219K, 5% free 7420K/7756K, paused 58ms, total 64ms
11-16 16:34:00.825: D/dalvikvm(1702): GC_FOR_ALLOC freed 281K, 5% free 8778K/9176K, paused 131ms, total 133ms
11-16 16:34:00.955: W/EGL_emulation(1702): eglSurfaceAttrib not implemented
11-16 16:34:01.405: I/Choreographer(1702): Skipped 31 frames! The application may be doing too much work on its main thread.
11-16 16:34:01.635: W/EGL_emulation(1702): eglSurfaceAttrib not implemented
11-16 16:34:02.295: W/EGL_emulation(1702): eglSurfaceAttrib not implemented
11-16 16:34:03.026: W/EGL_emulation(1702): eglSurfaceAttrib not implemented
11-16 16:34:03.625: W/EGL_emulation(1702): eglSurfaceAttrib not implemented
11-16 16:34:04.246: W/EGL_emulation(1702): eglSurfaceAttrib not implemented
11-16 16:34:04.875: W/EGL_emulation(1702): eglSurfaceAttrib not implemented
11-16 16:34:05.557: W/EGL_emulation(1702): eglSurfaceAttrib not implemented
11-16 16:34:06.206: W/EGL_emulation(1702): eglSurfaceAttrib not implemented
11-16 16:34:06.675: D/dalvikvm(1702): GREF has increased to 301
11-16 16:34:06.816: W/EGL_emulation(1702): eglSurfaceAttrib not implemented
11-16 16:34:07.458: W/EGL_emulation(1702): eglSurfaceAttrib not implemented
11-16 16:34:07.978: I/Choreographer(1702): Skipped 30 frames! The application may be doing too much work on its main thread.
11-16 16:34:08.296: W/EGL_emulation(1702): eglSurfaceAttrib not implemented
11-16 16:34:08.975: W/EGL_emulation(1702): eglSurfaceAttrib not implemented
11-16 16:34:09.686: W/EGL_emulation(1702): eglSurfaceAttrib not implemented
11-16 16:34:10.315: W/EGL_emulation(1702): eglSurfaceAttrib not implemented
11-16 16:34:10.945: W/EGL_emulation(1702): eglSurfaceAttrib not implemented
11-16 16:34:13.094: D/dalvikvm(1702): GC_FOR_ALLOC freed 367K, 5% free 10460K/10944K, paused 124ms, total 128ms
11-16 16:34:16.446: W/EGL_emulation(1702): eglSurfaceAttrib not implemented
11-16 16:34:16.965: I/Choreographer(1702): Skipped 30 frames! The application may be doing too much work on its main thread.
11-16 16:34:17.125: W/EGL_emulation(1702): eglSurfaceAttrib not implemented
11-16 16:34:17.625: I/Choreographer(1702): Skipped 30 frames! The application may be doing too much work on its main thread.
11-16 16:34:17.827: W/EGL_emulation(1702): eglSurfaceAttrib not implemented
11-16 16:34:18.355: I/Choreographer(1702): Skipped 32 frames! The application may be doing too much work on its main thread.
11-16 16:34:18.555: W/EGL_emulation(1702): eglSurfaceAttrib not implemented
11-16 16:34:19.145: I/Choreographer(1702): Skipped 34 frames! The application may be doing too much work on its main thread.
11-16 16:34:19.358: W/EGL_emulation(1702): eglSurfaceAttrib not implemented
11-16 16:34:20.103: W/EGL_emulation(1702): eglSurfaceAttrib not implemented
11-16 16:34:20.615: I/Choreographer(1702): Skipped 34 frames! The application may be doing too much work on its main thread.
11-16 16:34:20.880: W/EGL_emulation(1702): eglSurfaceAttrib not implemented
11-16 16:34:22.825: W/EGL_emulation(1702): eglSurfaceAttrib not implemented
11-16 16:34:23.445: I/Choreographer(1702): Skipped 35 frames! The application may be doing too much work on its main thread.
11-16 16:34:23.675: W/EGL_emulation(1702): eglSurfaceAttrib not implemented
11-16 16:34:24.195: D/dalvikvm(1702): GC_FOR_ALLOC freed 381K, 4% free 12129K/12628K, paused 289ms, total 291ms
11-16 16:34:24.355: I/Choreographer(1702): Skipped 40 frames! The application may be doing too much work on its main thread.
11-16 16:34:24.585: W/EGL_emulation(1702): eglSurfaceAttrib not implemented
11-16 16:34:25.215: I/Choreographer(1702): Skipped 36 frames! The application may be doing too much work on its main thread.
11-16 16:34:25.496: W/EGL_emulation(1702): eglSurfaceAttrib not implemented
11-16 16:34:26.025: I/Choreographer(1702): Skipped 30 frames! The application may be doing too much work on its main thread.
11-16 16:34:26.235: W/EGL_emulation(1702): eglSurfaceAttrib not implemented
11-16 16:34:26.735: D/dalvikvm(1702): GREF has increased to 401
11-16 16:34:26.795: I/Choreographer(1702): Skipped 32 frames! The application may be doing too much work on its main thread.
11-16 16:34:27.006: W/EGL_emulation(1702): eglSurfaceAttrib not implemented
11-16 16:34:29.516: W/EGL_emulation(1702): eglSurfaceAttrib not implemented
11-16 16:34:30.075: I/Choreographer(1702): Skipped 37 frames! The application may be doing too much work on its main thread.
11-16 16:34:30.305: W/EGL_emulation(1702): eglSurfaceAttrib not implemented
11-16 16:34:30.825: I/Choreographer(1702): Skipped 31 frames! The application may be doing too much work on its main thread.
11-16 16:34:31.046: W/EGL_emulation(1702): eglSurfaceAttrib not implemented
11-16 16:34:31.595: I/Choreographer(1702): Skipped 32 frames! The application may be doing too much work on its main thread.
11-16 16:34:31.816: W/EGL_emulation(1702): eglSurfaceAttrib not implemented
11-16 16:34:32.385: I/Choreographer(1702): Skipped 34 frames! The application may be doing too much work on its main thread.
11-16 16:34:32.615: W/EGL_emulation(1702): eglSurfaceAttrib not implemented
11-16 16:34:33.145: I/Choreographer(1702): Skipped 31 frames! The application may be doing too much work on its main thread.
11-16 16:34:33.365: W/EGL_emulation(1702): eglSurfaceAttrib not implemented
11-16 16:34:37.115: D/dalvikvm(1702): GC_FOR_ALLOC freed 392K, 4% free 13787K/14296K, paused 164ms, total 167ms
11-16 16:34:38.345: W/EGL_emulation(1702): eglSurfaceAttrib not implemented
11-16 16:34:45.285: W/EGL_emulation(1702): eglSurfaceAttrib not implemented
11-16 16:34:49.475: I/Choreographer(1702): Skipped 67 frames! The application may be doing too much work on its main thread.
如果我让应用程序在我的 AVD 上运行,LogCat 只会继续循环日志的这一部分:
11-16 16:34:31.046: W/EGL_emulation(1702): eglSurfaceAttrib not implemented
11-16 16:34:31.595: I/Choreographer(1702): Skipped 32 frames! The application may be doing too much work on its main thread.
我不知道如何解决这个问题。请帮忙!
最佳答案
您的 AboutActivity 类...
public class AboutActivity extends MainActivity {
请改成:
public class AboutActivity extends Activity {
正如其他人指出的那样,在构建您的 Intent 时,请使用 this 或 MainActivity.this。
关于java - 从 MainActivity 中的 onCreate() 启动另一个 Activity?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/20024254/
总的来说,我对ruby还比较陌生,我正在为我正在创建的对象编写一些rspec测试用例。许多测试用例都非常基础,我只是想确保正确填充和返回值。我想知道是否有办法使用循环结构来执行此操作。不必为我要测试的每个方法都设置一个assertEquals。例如:describeitem,"TestingtheItem"doit"willhaveanullvaluetostart"doitem=Item.new#HereIcoulddotheitem.name.shouldbe_nil#thenIcoulddoitem.category.shouldbe_nilendend但我想要一些方法来使用
我试图在一个项目中使用rake,如果我把所有东西都放到Rakefile中,它会很大并且很难读取/找到东西,所以我试着将每个命名空间放在lib/rake中它自己的文件中,我添加了这个到我的rake文件的顶部:Dir['#{File.dirname(__FILE__)}/lib/rake/*.rake'].map{|f|requiref}它加载文件没问题,但没有任务。我现在只有一个.rake文件作为测试,名为“servers.rake”,它看起来像这样:namespace:serverdotask:testdoputs"test"endend所以当我运行rakeserver:testid时
作为我的Rails应用程序的一部分,我编写了一个小导入程序,它从我们的LDAP系统中吸取数据并将其塞入一个用户表中。不幸的是,与LDAP相关的代码在遍历我们的32K用户时泄漏了大量内存,我一直无法弄清楚如何解决这个问题。这个问题似乎在某种程度上与LDAP库有关,因为当我删除对LDAP内容的调用时,内存使用情况会很好地稳定下来。此外,不断增加的对象是Net::BER::BerIdentifiedString和Net::BER::BerIdentifiedArray,它们都是LDAP库的一部分。当我运行导入时,内存使用量最终达到超过1GB的峰值。如果问题存在,我需要找到一些方法来更正我的代
Rails2.3可以选择随时使用RouteSet#add_configuration_file添加更多路由。是否可以在Rails3项目中做同样的事情? 最佳答案 在config/application.rb中:config.paths.config.routes在Rails3.2(也可能是Rails3.1)中,使用:config.paths["config/routes"] 关于ruby-on-rails-Rails3中的多个路由文件,我们在StackOverflow上找到一个类似的问题
使用带有Rails插件的vim,您可以创建一个迁移文件,然后一次性打开该文件吗?textmate也可以这样吗? 最佳答案 你可以使用rails.vim然后做类似的事情::Rgeneratemigratonadd_foo_to_bar插件将打开迁移生成的文件,这正是您想要的。我不能代表textmate。 关于ruby-使用VimRails,您可以创建一个新的迁移文件并一次性打开它吗?,我们在StackOverflow上找到一个类似的问题: https://sta
我需要从一个View访问多个模型。以前,我的links_controller仅用于提供以不同方式排序的链接资源。现在我想包括一个部分(我假设)显示按分数排序的顶级用户(@users=User.all.sort_by(&:score))我知道我可以将此代码插入每个链接操作并从View访问它,但这似乎不是“ruby方式”,我将需要在不久的将来访问更多模型。这可能会变得很脏,是否有针对这种情况的任何技术?注意事项:我认为我的应用程序正朝着单一格式和动态页面内容的方向发展,本质上是一个典型的网络应用程序。我知道before_filter但考虑到我希望应用程序进入的方向,这似乎很麻烦。最终从任何
我想要做的是有2个不同的Controller,client和test_client。客户端Controller已经构建,我想创建一个test_clientController,我可以使用它来玩弄客户端的UI并根据需要进行调整。我主要是想绕过我在客户端中内置的验证及其对加载数据的管理Controller的依赖。所以我希望test_clientController加载示例数据集,然后呈现客户端Controller的索引View,以便我可以调整客户端UI。就是这样。我在test_clients索引方法中试过这个:classTestClientdefindexrender:template=>
我在我的项目中添加了一个系统来重置用户密码并通过电子邮件将密码发送给他,以防他忘记密码。昨天它运行良好(当我实现它时)。当我今天尝试启动服务器时,出现以下错误。=>BootingWEBrick=>Rails3.2.1applicationstartingindevelopmentonhttp://0.0.0.0:3000=>Callwith-dtodetach=>Ctrl-CtoshutdownserverExiting/Users/vinayshenoy/.rvm/gems/ruby-1.9.3-p0/gems/actionmailer-3.2.1/lib/action_mailer
刚入门rails,开始慢慢理解。有人可以解释或给我一些关于在application_controller中编码的好处或时间和原因的想法吗?有哪些用例。您如何为Rails应用程序使用应用程序Controller?我不想在那里放太多代码,因为据我了解,每个请求都会调用此Controller。这是真的? 最佳答案 ApplicationController实际上是您应用程序中的每个其他Controller都将从中继承的类(尽管这不是强制性的)。我同意不要用太多代码弄乱它并保持干净整洁的态度,尽管在某些情况下ApplicationContr
我想向我的Controller传递一个参数,它是一个简单的复选框,但我不知道如何在模型的form_for中引入它,这是我的观点:{:id=>'go_finance'}do|f|%>Transferirde:para:Entrada:"input",:placeholder=>"Quantofoiganho?"%>Saída:"output",:placeholder=>"Quantofoigasto?"%>Nota:我想做一个额外的复选框,但我该怎么做,模型中没有一个对象,而是一个要检查的对象,以便在Controller中创建一个ifelse,如果没有检查,请帮助我,非常感谢,谢谢