與asp.net MVC2

Question

在正常asp.net以下工作檢測瀏覽器：

private float getInternetExplorerVersion() 
{ 
    // Returns the version of Internet Explorer or a -1 
    // (indicating the use of another browser). 
    float rv = -1; 
    System.Web.HttpBrowserCapabilities browser = Request.Browser; 
    if (browser.Browser == "IE") 
    rv = (float)(browser.MajorVersion + browser.MinorVersion); 
    return rv; 
} 

但在asp.net MVC2在給出錯誤 「System.Web.HttpBrowserCapabilities瀏覽器=的Request.Browser;」：

不能鍵入 'System.Web.HttpBrowserCapabilitiesBase' 隱式轉換爲 'System.Web.HttpBrowserCapabilities'

感謝 ARNAB

Answer 1

這因爲Browser屬性的類型是HttpBrowserCapabilitiesBase而不是HttpBrowserCapabilities。因此，無論使用隱var或指定適當的類型：

float rv = -1; 
var browser = Request.Browser; 
if (browser.Browser == "IE") 
    rv = (float)(browser.MajorVersion + browser.MinorVersion); 

或者如果你喜歡打字大量的代碼：

float rv = -1; 
System.Web.HttpBrowserCapabilitiesBase browser = Request.Browser; 
if (browser.Browser == "IE") 
    rv = (float)(browser.MajorVersion + browser.MinorVersion);