//文字内容的左边距
UIView* leftView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 8, 30)];
leftView.backgroundColor = [UIColor clearColor];
tf.leftView = leftView;
//影响光标颜色
tf.tintColor = [UIColor whiteColor];
原文：http://www.cnblogs.com/wfg253744189/p/4602220.html