類型轉換錯誤

Question

int age = txtAge.Text; 

，我發現了錯誤：

Error 2 Cannot implicitly convert type 'string' to 'int' 

Answer 1

int age = int.Parse(txtAge.Text); 

Answer 2

嘗試

int age; 
bool result = Int32.TryParse(txtAge.Text, out age); 

if (result) 
{ 
    // Parse succeeded and get the result in age 
} 
else 
{ 
    // Parse failed 
} 

見Int32.TryParse Method (String, Int32)

The TryParse method is like the Parse method, except the TryParse method does not throw an exception if the conversion fails. It eliminates the need to use exception handling to test for a FormatException in the event that s is invalid and cannot be successfully parsed.

Answer 3

當然可以」 t，int和string是兩種完全不同的類型。然而，最簡單的解決辦法是：

int age = Int32.Parse(txtAge.Text); 

更安全的是：

int age; 
Int32.TryParse(txtAge.Text, out age);