如何使用Xcode调试器打印出一个属性的内容？ [英] How to print out a property's contents using Xcode debugger?

问题描述

我正在编写一个iOS应用程序，我需要使用内置的Xcode调试器的帮助。假设我有一个名为 HomeViewController 的对象，它具有三个属性

  @property （非原子）BOOL完成; 
 @property（nonatomic，strong）NSArray * myArray; 
 @property（nonatomic，strong）NSString * myName; 
 
 @synthesize finished = _finished，myArray = _myArray，myName = _myName; 
  

假设我在这个类中有一个断点。我如何查看这些属性的内容？我尝试了诸如 po myName ， print myName 和 print [self myName] 但我无法弄清楚如何做到这一点。我试过使用LLDB，但我一直得到这个人遇到的同样的错误（

解决方案

一旦您放置了断点，运行并且程序在断点停止，将光标悬停在变量/您希望看到的价值如下：

NSLog（@％@，yourLabel.text）; 到查看该标签/其他对象类型的内容。

另一个选项是在控制台中运行GDB，如下所示：

  gdb 
附上<您的进程名称> 
  

然后使用 po 对象）命令来查看像这样的变量的值：

  po变量名称
  

要查看原始类型的值（ int ， float ， long ， double ， char 等等），您可以在控制台中运行GDB时使用 print 命令，如下所示：

 打印yourPrimitiveVariable 
  

希望这有助于您！

编辑：

使用 po 命令，可以打印出一个同时使用属性名称（ self.myProperty ）或伊娃名称（可能 _myProperty ）的对象。我在这里证明这一点：

I'm writing an iOS app and I need help using the built-in Xcode debugger. Suppose I have an object called HomeViewController that has three properties

@property (nonatomic) BOOL finished;
@property (nonatomic, strong) NSArray *myArray;
@property (nonatomic, strong) NSString *myName;

@synthesize finished = _finished, myArray = _myArray, myName = _myName;

Suppose I have a breakpoint in this class. How would I view the contents of these properties? I've tried things such as po myName, print myName and print [self myName] but I can't figure out how to do this. I've tried using LLDB but I keep getting the same error that this person encountered (lldb fails to print variable values with "error: reference to 'id' is ambiguous") . The accepted answer to this question was, LLDB is broken and that I should just use GDB; however, I refuse to accept that something so fundamental is broken.

Nevertheless, I've also tried using GDB with similar commands as above; however, I can't get GDB to work either. Help please

解决方案

Once you place a breakpoint, run, and the program stops at the breakpoint, hover your cursor over the variable/value you want to see like this:

You could also place an NSLog(@"%@", yourLabel.text); to view the contents of that label/other object type.

One other option is to run GDB in the console like this:

gdb
attach <your process name>

And then use the po (print-object) command to view the value of a variable like this:

po variableName

To view the value of primitive types (int, float, long, double, char, etc.), you can just use the print command while running GDB in the console like this:

print yourPrimitiveVariable

Hope this helps!

EDIT:

With the po command, you can print out the value of an object using both the property name (self.myProperty) or the ivar name (possibly _myProperty). I demonstrate this here:

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