public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
List<string> st;
private void Form1_Load(object sender, EventArgs e)
{
List<string> st = new List<string> { "ftyrt", "rtyr" };
} private void button1_Click(object sender, EventArgs e)
{
label1.Text = st[0]; //报错,未将对象应用设置到对象的实例
}
}请问,为什么会报错呢?
{
public Form1()
{
InitializeComponent();
}
List<string> st;
private void Form1_Load(object sender, EventArgs e)
{
List<string> st = new List<string> { "ftyrt", "rtyr" };
} private void button1_Click(object sender, EventArgs e)
{
label1.Text = st[0]; //报错,未将对象应用设置到对象的实例
}
}请问,为什么会报错呢?
private void Form1_Load(object sender, EventArgs e)
{
List<string> st = new List<string> { "ftyrt", "rtyr" };
}
红色部分去掉
你的赋值实际上没有作用。
List<string> st = new List<string> { "ftyrt", "rtyr" };
=>
this.st = new List<string> { "ftyrt", "rtyr" };