if多条件语句如何简化，减少内存消耗，Creatchartx();为获取图像的方法

if (flag == true)//如果按钮被点击
{
if (comboBox1.Text == "CHR1" && comboBox2.Text == "1" && comboBox3.Text == "1002")
{

//return Creatchart1();
Creatchart5();

}
else if (comboBox1.Text == "CHR2" && comboBox2.Text == "1" && comboBox3.Text == "1002")
{
Creatchart6();
}
else if (comboBox1.Text == "CHR1" && comboBox2.Text == "2" && comboBox3.Text == "1002")
{
Creatchart7();
}
else if (comboBox1.Text == "CHR2" && comboBox2.Text == "2" && comboBox3.Text == "1002")
{
Creatchart8();
}
else if (comboBox1.Text == "CHR1" && comboBox2.Text == "1" && comboBox3.Text == "1009")
{

//return Creatchart1();
Creatchart1();

}
else if (comboBox1.Text == "CHR2" && comboBox2.Text == "1" && comboBox3.Text == "1009")
{
Creatchart2();
}
else if (comboBox1.Text == "CHR1" && comboBox2.Text == "2" && comboBox3.Text == "1009")
{
Creatchart3();
}
else if (comboBox1.Text == "CHR2" && comboBox2.Text == "2" && comboBox3.Text == "1009")
{
Creatchart4();
}
}
}