1.C#简单的口源计算贷款的源代码调试错误

C#简单的计算贷款的源代码调试错误

       private void button2_Click(object sender, EventArgs e)

        {

        textBox4.Text = String.Format("{ 0,-:c5} { 1,8:c5}{ 2,9:c5){ 3,:c5}{ 4,:c5}",

        "loanAmout", "ARate", "LPeriod", "mouthlyPayment", "totalPayment");

        textBox1.Text = "";

        textBox2.Text = "";

        textBox3.Text = "";

        }

       有错，该是源码怎么自己制作源码monthlyPayment

       格式字符在前