如何使用數組成員？

Question

爲什麼我在使用時出現錯誤struct array in struct？

public struct Tables 
{ 
    public string name; 
} 

public struct Schema 
{ 
    public string name; 
    public Tables[] tables; //Declarate struct array in struct 
} 

我使用了結構與此代碼：

Schema schema; 

private void Form1_Load(object sender, EventArgs e) 
{ 
    schema.name = "schemaName"; 
    schema.tables[0].name = "tables1Name"; // Error in here: Object reference not set to an instance of an object 
} 

Answer 1

需要初始化您的數組：

schema.name = "schemaName"; 
schema.tables = new Tables[10]; 
schema.tables[0].name = "tables1"; 

Answer 2

這是因爲schema.tables從未初始化，因此是無效

嘗試

private void Form1_Load(object sender, EventArgs e) 
{ 
    schema.name = "schemaName"; 
    schema.tables = new Tables[5]; 
    schema.tables[0].name = "tables1"; // Error ini here: Object reference not set to an instance of an object 
}