使用异步方法通过内置的 Task.Delay 方法创建延迟.这将导致执行被暂停，然后在指定的时间后结束之后恢复执行.

Use an async method to create a delay using the built-in Task.Delay method. This will cause execution to be paused and then resumed after the specified time without blocking the current thread.

async Task UseDelay()
{
    await Task.Delay(1000); // wait for 1 second
}

根据您的具体情况

async void button1_Click(object sender, EventArgs e)
{ 
    for (var i = 0; i < 10; i++) 
    {
        textBox1.BackColor = Color.Red;         
        await Task.Delay(100);
        textBox1.BackColor = Color.Yellow;    
        await Task.Delay(100);
    }
 }