Visual studio 2012 and Qt4.8.5 : How to see QString contents in debug mode.

Question

I use visual studio 2012 and Qt4.8.5, unfortunately I can not see the QString text variable when I work in debug mode. Is someone has a tip allow it ? Qt4.8.5 plug-in doesn't exist for VS2012.

Thank a lot

Xavier

Answer 1

There is a quick and explicit solution (MSVC native, no need for plugins nor setting up .dat files), see my answer from here

Say you have QString str (Qt4), then add to the debugger watch window:

((str).d)->array,su 

the appendix ,su tells the debugger to interpret the data as unicode and null terminated string.

Note: For a Qt5 QString str it could be

(char*)str.d + str.d->offset,su

Answer 2

the autoexp.dat is not used unless you set the Debugger options to "Enable native Edit and Continue"

here is my natvis implementation of the QString for 4.8.5 (expands only the first 25 chars)

<Type Name="QString">
    <DisplayString>"{d->data,sub}"</DisplayString>
    <StringView>d->data,sub</StringView>
    <Expand>
        <Item Condition="d->size &gt;= 0" Name="[size]">d->size</Item>
        <Item Condition="d->size &gt; 0" Name="[referenced]">d->ref._q_value</Item>
        <ArrayItems Condition="d->size&lt;=25">
            <Size>d->size</Size>
            <ValuePointer>d->data,c</ValuePointer>
        </ArrayItems>
        <ArrayItems Condition="d->size&gt;25">
            <Size>25</Size>
            <ValuePointer>d->data,c</ValuePointer>
        </ArrayItems>
        <Item Condition="d->size&gt;25" Name="...">d->size - 25</Item>
    </Expand>
</Type>

at least the qt4.natvis can coexist with the qt5.natvis as one or the other fails to load correctly...

Answer 3

For Visual 2015, 2017 and 2019,
just install the dedicated Qt plugin for Visual.
Download it from here

Answer 4

For me, in Qt5 and Visual Studio 2012, i just did this:

Project options -> debugging -> Debugger type -> Set it from Auto to Mixed.

Not the strings are displayed in the watch.

Answer 5

For Visual Studio 2015...

Tools > Options > Debugging > General > Check "Use Native Compatibility Mode"

Answer 6

For me, this worked for QString qStr :

p qStr.toStdString();

I executed this in command line (available in visual studio), worked in gdb and lldb.