How can I add adjustable current to a DC-DC converter?
I would like to use a DC-DC converter to adjust the voltage and the current too.

I would like to adjustable the voltage and the current too in the same time.

It doesn't work that way.  A power supply can control one degree of freedom, such as the voltage or the current, but not two.  The load determines the other degree of freedom.

For example, if you have a fixed-voltage 5 V supply, you have no say over the current.  If someone connects a 1 k&Omega; resistor to the supply, then the supply will be forced to (as long as it maintains the output at 5 V) to supply 5 mA.  With a 100 &Omega; resistor, the current will be 50 mA.

Likewise, a constant-current supply of 100 mA has no say over the voltage.  If you connect a 47 &Omega; resistor to it, it has to put out 4.7 V to maintain the 100 mA.

What is possible is a supply that puts out some fixed voltage or current, whichever is lower.  These are actually fairly common, and are sometimes called current limited supplies.  For example, a 5 V supply current-limited to 100 mA will put out 5 V when you connect a 100 &Omega; resistor to it.  That's because the load (the resistor) draws (5 V)/(100 &Omega;) = 50 mA.  Since (50 mA) &lt; (100 mA), the supply continues to put out the fixed 5 V.

However, let's say you connect a 20 &Omega; resistor to this supply.  If it maintained 5 V, the current would be (5 V)/(20 &Omega;) = 250 mA.  That is greater than the current limit of 100 mA.  We know therefore that the supply will switch to constant current mode.  That means the output voltage will drop to (20 &Omega;)(100 mA) = 2 V.