init() {

        super.init(frame: CGRect(x: , y: , width: yourWidth, height: yourHeight))

　　　　　　

　　　　　//光标颜色修改　　

　　　　　self.tintColor = UIColor.orangeColor()

    }

override func editingRectForBounds(bounds: CGRect) -> CGRect {        

        return CGRectInset(bounds, , );

    }

    override func textRectForBounds(bounds: CGRect) -> CGRect {

        return CGRectInset(bounds, , )

    }

    override func placeholderRectForBounds(bounds: CGRect) -> CGRect {

                return CGRectInset(bounds, , )

    }

    override func leftViewRectForBounds(bounds: CGRect) -> CGRect {

        var iconRect = super.leftViewRectForBounds(bounds)

        iconRect.origin.x = iconRect.origin.x + 

        return iconRect

    }

//其他非相关代码已省略

func setupMobelLoginUI(){

        ...

        mobTxtFld.backgroundColor = LoginConst.tfBackgroundColor

        mobTxtFld.layer.cornerRadius = LoginConst.commonHeight /

        mobTxtFld.clipsToBounds = true

        mobTxtFld.layer.borderColor = LoginConst.tfBorderColor.CGColor

        mobTxtFld.layer.borderWidth = 

        //leftView相关设置

        let mobIcon = UIImageView(image: UIImage(named: "login_mobile"))

        mobTxtFld.leftViewMode = UITextFieldViewMode.Always

        mobTxtFld.leftView = mobIcon

        view.addSubview(mobTxtFld)

        mobTxtFld.snp_makeConstraints { (make) in

            make.top.equalTo(titleLb.snp_bottom).offset(LoginConst.topVOffset)

            make.centerX.equalTo(self.view)

            make.width.equalTo()

            make.height.equalTo(LoginConst.commonHeight)

        }

        
　　　　 //leftView相关设置

        let codeIcon = UIImageView(image: UIImage(named: "login_yanzheng"))

        verifyCodeTxtFld.leftViewMode = UITextFieldViewMode.Always

        verifyCodeTxtFld.leftView = codeIcon

        verifyCodeTxtFld.backgroundColor = LoginConst.tfBackgroundColor

        verifyCodeTxtFld.layer.cornerRadius = LoginConst.commonHeight /

        verifyCodeTxtFld.layer.masksToBounds = true

        verifyCodeTxtFld.layer.borderColor = LoginConst.tfBorderColor.CGColor

        verifyCodeTxtFld.layer.borderWidth = 

        view.addSubview(verifyCodeTxtFld)

        verifyCodeTxtFld.snp_makeConstraints { (make) in

          make.top.equalTo(mobTxtFld.snp_bottom).offset(LoginConst.verifyVMargin)

            make.width.height.centerX.equalTo(mobTxtFld)

        }

    ...

    }