我试图将左右箭头键绑定到Tkinter中的事件,但是当我运行程序时,它似乎没有触发事件.这是代码:
from Tkinter import *
main = Tk()
def leftKey(event):
print "Left key pressed"
def rightKey(event):
print "Right key pressed"
frame = Frame(main, width=100, height=100)
frame.bind('<Left>', leftKey)
frame.bind('<Right>', rightKey)
frame.pack()
frame.mainloop()
为什么这不起作用？
我正在尝试在适用于 Linux 的 Windows 子系统 (Ubuntu) 上使用全新安装的 MySQL，但似乎无法连接到它。我总是收到错误：
WSL: Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (2)
我试过了：
--skip-grant-tables编辑/etc/mysql/mysql.conf.d/mysqld.cnf并重启即可使用该文件/var/run/mysqld/mysqld.sock也从未显示出来，尽管我认为这是因为 WSL 一开始就没有完美的套接字支持，但它应该仍然可以工作。我怀疑问题可能是 WSL 特有的，也许我应该尝试更新到 WSL2？我不知道还有什么问题。
我想在Android Studio v0.5.4中启动一个项目,但是我一直收到以下错误:
[ 130340] WARN - nal.AbstractExternalSystemTask - Cause: unexpected end of block data
com.intellij.openapi.externalSystem.model.ExternalSystemException: Cause: unexpected end of block data
at org.jetbrains.plugins.gradle.service.project.GradleExecutionHelper.execute(GradleExecutionHelper.java:206)
at org.jetbrains.plugins.gradle.service.project.GradleProjectResolver.resolveProjectInfo(GradleProjectResolver.java:116)
at org.jetbrains.plugins.gradle.service.project.GradleProjectResolver.resolveProjectInfo(GradleProjectResolver.java:64)
at com.intellij.openapi.externalSystem.service.remote.RemoteExternalSystemProjectResolverImpl$1.produce(RemoteExternalSystemProjectResolverImpl.java:41)
at com.intellij.openapi.externalSystem.service.remote.RemoteExternalSystemProjectResolverImpl$1.produce(RemoteExternalSystemProjectResolverImpl.java:37)
at com.intellij.openapi.externalSystem.service.remote.AbstractRemoteExternalSystemService.execute(AbstractRemoteExternalSystemService.java:59)
at com.intellij.openapi.externalSystem.service.remote.RemoteExternalSystemProjectResolverImpl.resolveProjectInfo(RemoteExternalSystemProjectResolverImpl.java:37)
at com.intellij.openapi.externalSystem.service.remote.wrapper.ExternalSystemProjectResolverWrapper.resolveProjectInfo(ExternalSystemProjectResolverWrapper.java:49)
at com.intellij.openapi.externalSystem.service.internal.ExternalSystemResolveProjectTask.doExecute(ExternalSystemResolveProjectTask.java:48)
at com.intellij.openapi.externalSystem.service.internal.AbstractExternalSystemTask.execute(AbstractExternalSystemTask.java:137)
at com.intellij.openapi.externalSystem.service.internal.AbstractExternalSystemTask.execute(AbstractExternalSystemTask.java:123)
at com.intellij.openapi.externalSystem.util.ExternalSystemUtil$3.execute(ExternalSystemUtil.java:467)
at com.intellij.openapi.externalSystem.util.ExternalSystemUtil$4$2.run(ExternalSystemUtil.java:546)
at com.intellij.openapi.progress.impl.ProgressManagerImpl$TaskRunnable.run(ProgressManagerImpl.java:464)
at com.intellij.openapi.progress.impl.ProgressManagerImpl$2.run(ProgressManagerImpl.java:178)
at com.intellij.openapi.progress.ProgressManager.executeProcessUnderProgress(ProgressManager.java:209)
at com.intellij.openapi.progress.impl.ProgressManagerImpl.executeProcessUnderProgress(ProgressManagerImpl.java:212)
at com.intellij.openapi.progress.impl.ProgressManagerImpl.runProcess(ProgressManagerImpl.java:171)
at com.intellij.openapi.progress.impl.ProgressManagerImpl$8.run(ProgressManagerImpl.java:373)
at com.intellij.openapi.application.impl.ApplicationImpl$8.run(ApplicationImpl.java:419)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
at java.util.concurrent.FutureTask.run(FutureTask.java:262)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:744)
at com.intellij.openapi.application.impl.ApplicationImpl$1$1.run(ApplicationImpl.java:149)
可能相关的是,当我尝试访问build.gradle时出现此错误:
InvalidVirtualFileAccessException: Accessing invalid virtual file: …我的 Rails 应用程序中有一个模型类别，它有一个属性名称。添加另一个模型的项目时，我希望用户可以根据类变量@categories 从下拉列表中选择类别名称。
为此，我需要从 Category 类型的数组生成名称的字符串数组，但我不太确定如何在不将整个 Category 对象的字符串表示形式放入每个下拉项中的情况下执行此操作。
有谁知道如何做到这一点——从类对象数组中获取类属性数组？