Ekhlass/Flutter_Documentation · Datasets at Hugging Face

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Debugger, and Memory views.<topic_end>
<topic_start>
Watch application output
The console shows the application’s standard output (stdout):<topic_end>
<topic_start>
Explore inspected widgets
If you click a widget on the Inspector screen,
the variable for this widget displays in the Console:<topic_end>
<topic_start>
Evaluate expressions
In the console, you can evaluate expressions for a paused
or running application, assuming that you are running
your app in debug mode:To assign an evaluated object to a variable,
use $0, $1 (through $5) in the form of var x = $0:<topic_end>
<topic_start>
Browse heap snapshot
To drop a variable to the console from a heap snapshot,
do the following:The Console screen displays both live and static
inbound and outbound references, as well as field values:
<topic_end>
<topic_start>Using the Network View
info Note
The network view works with all Flutter and Dart applications.<topic_end>
<topic_start>
What is it?
The network view allows you to inspect HTTP, HTTPS, and web socket traffic from
your Dart or Flutter application.<topic_end>
<topic_start>
How to use it
Network traffic should be recording by default when you open the Network page.
If it is not, click the Resume button in the upper left to
begin polling.Select a network request from the table (left) to view details (right). You can
inspect general and timing information about the request, as well as the content
of response and request headers and bodies.<topic_end>
<topic_start>
Search and filtering
You can use the search and filter controls to find a specific request or filter
requests out of the request table.To apply a filter, press the filter button (right of the search bar). You will
see a filter dialog pop up:The filter query syntax is described in the dialog. You can filter network
requests by the following keys:Any text that is not paired with an available filter key will be queried against
all categories (method, uri, status, type).Example filter queries:<topic_end>
<topic_start>
Other resources
HTTP and HTTPs requests are also surfaced in the Timeline as
asynchronous timeline events. Viewing network activity in the timeline can be
useful if you want to see how HTTP traffic aligns with other events happening
in your app or in the Flutter framework.To learn how to monitor an app’s network traffic and inspect
different types of requests using the DevTools,
check out a guided Network View tutorial.
The tutorial also uses the view to identify network activity that
causes poor app performance.
<topic_end>
<topic_start>Using the debugger
info Note
DevTools hides the Debugger tab if the app was launched
from VS Code because VS Code has a built-in debugger.<topic_end>
<topic_start>
Getting started
DevTools includes a full source-level debugger, supporting
breakpoints, stepping, and variable inspection.info Note
The debugger works with all Flutter and Dart applications.
If you are looking for a way to use GDB to remotely debug the
Flutter engine running within an Android app process,
check out flutter_gdb.When you open the debugger tab, you should see the source for the main
entry-point for your app loaded in the debugger.In order to browse around more of your application sources, click Libraries
(top right) or press Ctrl / Cmd + P.
This opens the libraries window and allows you
to search for other source files.<topic_end>
<topic_start>
Setting breakpoints
To set a breakpoint, click the left margin (the line number ruler)
in the source area. Clicking once sets a breakpoint, which should
also show up in the Breakpoints area on the left. Clicking
again removes the breakpoint.<topic_end>
<topic_start>
The call stack and variable areas
When your application encounters a breakpoint, it pauses there,
and the DevTools debugger shows the paused execution location
in the source area. In addition, the Call stack and Variables
areas populate with the current call stack for the paused isolate,
and the local variables for the selected frame. Selecting other
frames in the Call stack area changes the contents of the variables.Within the Variables area, you can inspect individual objects by
toggling them open to see their fields. Hovering over an object
in the Variables area calls toString() for that object and
displays the result.<topic_end>
<topic_start>
Stepping through source code
When paused, the three stepping buttons become active.In addition, the Resume button continues regular
execution of the application.<topic_end>
<topic_start>
Console output
Console output for the running app (stdout and stderr) is
displayed in the console, below the source code area.
You can also see the output in the Logging view.<topic_end>
<topic_start>
Breaking on exceptions
To adjust the stop-on-exceptions behavior, toggle the
Ignore dropdown at the top of the debugger view.Breaking on unhandled excepts only pauses execution if the
breakpoint is considered uncaught by the application code.
Breaking on all exceptions causes the debugger to pause

Debugger, and Memory views.<topic_end>

<topic_start>

Watch application output

The console shows the application’s standard output (stdout):<topic_end>

<topic_start>

Explore inspected widgets

If you click a widget on the Inspector screen,

the variable for this widget displays in the Console:<topic_end>

<topic_start>

Evaluate expressions

In the console, you can evaluate expressions for a paused

or running application, assuming that you are running

your app in debug mode:To assign an evaluated object to a variable,

use $0, $1 (through $5) in the form of var x = $0:<topic_end>

<topic_start>

Browse heap snapshot

To drop a variable to the console from a heap snapshot,

do the following:The Console screen displays both live and static

inbound and outbound references, as well as field values:

<topic_end>

<topic_start>Using the Network View

info Note

The network view works with all Flutter and Dart applications.<topic_end>

<topic_start>

What is it?

The network view allows you to inspect HTTP, HTTPS, and web socket traffic from

your Dart or Flutter application.<topic_end>

<topic_start>

How to use it

Network traffic should be recording by default when you open the Network page.

If it is not, click the Resume button in the upper left to

begin polling.Select a network request from the table (left) to view details (right). You can

inspect general and timing information about the request, as well as the content

of response and request headers and bodies.<topic_end>

<topic_start>

Search and filtering

You can use the search and filter controls to find a specific request or filter

requests out of the request table.To apply a filter, press the filter button (right of the search bar). You will

see a filter dialog pop up:The filter query syntax is described in the dialog. You can filter network

requests by the following keys:Any text that is not paired with an available filter key will be queried against

all categories (method, uri, status, type).Example filter queries:<topic_end>

<topic_start>

Other resources

HTTP and HTTPs requests are also surfaced in the Timeline as

asynchronous timeline events. Viewing network activity in the timeline can be

useful if you want to see how HTTP traffic aligns with other events happening

in your app or in the Flutter framework.To learn how to monitor an app’s network traffic and inspect

different types of requests using the DevTools,

check out a guided Network View tutorial.

The tutorial also uses the view to identify network activity that

causes poor app performance.

<topic_end>

<topic_start>Using the debugger

info Note

DevTools hides the Debugger tab if the app was launched

from VS Code because VS Code has a built-in debugger.<topic_end>

<topic_start>

Getting started

DevTools includes a full source-level debugger, supporting

breakpoints, stepping, and variable inspection.info Note

The debugger works with all Flutter and Dart applications.

If you are looking for a way to use GDB to remotely debug the

Flutter engine running within an Android app process,

check out flutter_gdb.When you open the debugger tab, you should see the source for the main

entry-point for your app loaded in the debugger.In order to browse around more of your application sources, click Libraries

(top right) or press Ctrl / Cmd + P.

This opens the libraries window and allows you

to search for other source files.<topic_end>

<topic_start>

Setting breakpoints

To set a breakpoint, click the left margin (the line number ruler)

in the source area. Clicking once sets a breakpoint, which should

also show up in the Breakpoints area on the left. Clicking

again removes the breakpoint.<topic_end>

<topic_start>

The call stack and variable areas

When your application encounters a breakpoint, it pauses there,

and the DevTools debugger shows the paused execution location

in the source area. In addition, the Call stack and Variables

areas populate with the current call stack for the paused isolate,

and the local variables for the selected frame. Selecting other

frames in the Call stack area changes the contents of the variables.Within the Variables area, you can inspect individual objects by

toggling them open to see their fields. Hovering over an object

in the Variables area calls toString() for that object and

displays the result.<topic_end>

<topic_start>

Stepping through source code

When paused, the three stepping buttons become active.In addition, the Resume button continues regular

execution of the application.<topic_end>

<topic_start>

Console output

Console output for the running app (stdout and stderr) is

displayed in the console, below the source code area.

You can also see the output in the Logging view.<topic_end>

<topic_start>

Breaking on exceptions

To adjust the stop-on-exceptions behavior, toggle the

Ignore dropdown at the top of the debugger view.Breaking on unhandled excepts only pauses execution if the

breakpoint is considered uncaught by the application code.

Breaking on all exceptions causes the debugger to pause