已知椭圆\(C\):\( \dfrac {x^{2}}{a^{2}}+ \dfrac {y^{2}}{b^{2}}=1(a > b > 0)\)的两个焦点分别为\(F_{1}\),\(F_{2}\),离心率为\( \dfrac {1}{2}.\)设过点\(F_{2}\)的直线\(l\)与椭圆\(C\)相交于不同两点\(A\),\(B\),\(\triangle AB F_{ 1 }\)周长为\(8\).
\((\)Ⅰ\()\)求椭圆\(C\)的标准方程;
\((\)Ⅱ\()\)已知点\(T(4,0)\),证明:当直线\(l\)变化时,总有\(TA\)与\(TB\)的斜率之和为定值.