Identify KeyPress "Enter" in textBox

 Hi,
I have a textBox where a I enter some text. After this is done I will press "Enter" on the keyboard to call the control Button1 that I have on the same form.
Assume that I have: textBox1 and Button1 on my form. In somehow I will need to identify that "Enter" is pressed in the textBox1 ?
How will that be possible ?
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