Question

我希望我的label2.Text显示乘法表的每个连续结果，但只显示最后一个结果。我做了每个复选框只等于一个数学表。 checkbox1 =乘法表1，checkbox2 =乘法表2等等...... 为什么我的Windows窗体中的label2.Text属性中只显示最后一个结果？附：我正在学习C＃的入门课程。

int multiplyWith;
int multiplyNumber;
for (multiplyNumber = 1; multiplyNumber <= 12; multiplyNumber++)
{
    if (checkBox1.Checked == true)
    {
        multiplyWith = 1;
        int sum = multiplyNumber * multiplyWith;
        label2.Visible = true;
        label2.Text = sum + "\n";

    }
    else if (checkBox2.Checked == true)
    {
        multiplyWith = 2;
        int sum = multiplyNumber * multiplyWith;
        label2.Visible = true;
        label2.Text = sum + "\n";
    }
}

Answer 1

您没有连接结果，只是设置当前值。

这可行，但不是最干净/最有效的方法：

label2.Text += sum + "\n";

首先尝试使用StringBuilder生成结果，最后为文本框指定StringBuilder值。

StringBuilder sum = new StringBuilder();
int multiplyWith = checkBox1.Checked ? 1 : 2;

for (int multiplyNumber = 1; multiplyNumber <= 12; multiplyNumber++)
{
    sum.AppendLine(multiplyNumber * multiplyWith);
}    

label2.Visible = true;
label2.Text = sum.ToString();

Answer 2

如果您愿意，可以将其更改为：

int multiplyWith;
int multiplyNumber;
var results = string.Empty;
for (multiplyNumber = 1; multiplyNumber <= 12; multiplyNumber++)
{
    if (checkBox1.Checked == true)
    {
        multiplyWith = 1;
        int sum = multiplyNumber * multiplyWith;
        label2.Visible = true;
        results += sum + "\n"
    }
    else if (checkBox2.Checked == true)
    {
        multiplyWith = 2;
        int sum = multiplyNumber * multiplyWith;
        label2.Visible = true;
        results += sum + "\n"
    } 
}

循环退出后：

label2.Text = results;

Answer 3

你可以从

编辑这一行

label2.Text = sum + "\n";

到

label2.Text += sum + "\n";

为什么我的for循环只显示最后的结果？

3 个答案: