波斯马BOSSMA Information Technology

由于多线程可能导致对控件访问的不一致，导致出现问题。C#中默认是要线程安全的，即在访问控件时需要首先判断是否跨线程，如果是跨线程的直接访问，在运行时会抛出异常。

解决办法有两个：

1、不进行线程安全的检查

2、通过委托的方式，在控件的线程上执行

public partial class Form1 : Form
??? {
??????? public Form1()
??????? {
??????????? InitializeComponent();
??????????? //方法一：不进行跨线程安全检查
??????????? //System.Windows.Forms.Control.CheckForIllegalCrossThreadCalls = false;
??????? }

??????? private void button1_Click(object sender, EventArgs e)
??????? {
??????????? Thread th1 = new Thread(new ThreadStart(CalNum));
??????????? th1.Start();
??????? }

??????? private void CalNum()
??????? {
??????????? //button1.Enabled = false;

??????????? int result = 0;
??????????? for (int i = 1; i < 100000000; i++)
??????????? {
??????????????? result += i;
??????????? }

??????????? SetCalResult(result);

??????????? //button1.Enabled = true;
??????? }

??????? //方法二：检查是否跨线程，然后将方法加入委托，调用委托
??????? public delegate void SetTextHandler(int result);
??????? private void SetCalResult(int result)
??????? {
??????????? if (label2.InvokeRequired == true)
??????????? {
??????????????? SetTextHandler set = new SetTextHandler(SetCalResult);//委托的方法参数应和SetCalResult一致
??????????????? label2.Invoke(set, new object[] { result }); //此方法第二参数用于传入方法,代替形参result
??????????? }
??????????? else
??????????? {
??????????????? label2.Text = result.ToString();
??????????? }
??????? }
??? }

关键字: 委托 跨线程访问