的錯誤,我這裏有這樣的代碼,但我不斷收到同樣的錯誤。有人能告訴我我做錯了什麼嗎?無法投型「system.windows.forms.textbox」的對象鍵入「System.IConvertible」爲C#的形式
private void button1_Click(object sender, EventArgs e)
{
double gallonsToBuy;//for equation
double WALL_LENGTH; //holds wall length
double WALL_HEIGHT; //holds wall height
int NUM_DOORS; //holds number of doors
int NUM_WINDOWS; //holds number of windows
int NUM_COATS; //holds number of coats of paint
const double GALLON_SF = 350; //one gallon covers 350 square feet
//allows user to input their numbers
WALL_LENGTH = Convert.ToDouble(textBox1);
WALL_HEIGHT = Convert.ToDouble(textBox2);
NUM_DOORS = Convert.ToInt32(textBox3);
NUM_WINDOWS = Convert.ToInt32(textBox4);
NUM_COATS = Convert.ToInt32(textBox5);
//Equation
gallonsToBuy = ((((WALL_LENGTH * WALL_HEIGHT) - (20 * NUM_DOORS) - (15 * NUM_WINDOWS)) * NUM_COATS) /350);
label7.Text = "Gallons to buy =" +gallonsToBuy;
}
請不要試圖解釋錯誤信息。從調試器複製消息,[編輯](https://stackoverflow.com/posts/46437200/edit)你的問題並粘貼進去。 –
'textBox1.Text' !!!!!而不是'textBox1' – Transcendent