我想知道关键声音的值是否存在,但下面的代码不适用于我
if (roamingSettings.Values["Sound"] == null)
答案 0 :(得分:2)
"值"是一个集合,其成员可能会这样检查。
if(roamingSettings.Values.ContainsKey("Sound"))
{
var myRoamingSettingValue = roamingSettings.Values["Sound"];
// do stuff with the value you pulled back
}
else
{
// your roaming settings collection doesn't contain the value you are interested in.
// Add it?
roamingSettings.Values.Add("Sound", "myDefaultValue");
}
答案 1 :(得分:1)
我想你想要这个
/// <summary>Returns if a setting is found in the specified storage strategy</summary>
/// <param name="key">Path of the setting in storage</param>
/// <param name="location">Location storage strategy</param>
/// <returns>Boolean: true if found, false if not found</returns>
public static bool SettingExists(string key, StorageStrategies location = StorageStrategies.Local)
{
switch (location)
{
case StorageStrategies.Local:
return Windows.Storage.ApplicationData.Current.LocalSettings.Values.ContainsKey(key);
case StorageStrategies.Roaming:
return Windows.Storage.ApplicationData.Current.RoamingSettings.Values.ContainsKey(key);
default:
throw new NotSupportedException(location.ToString());
}
}
public enum StorageStrategies
{
/// <summary>Local, isolated folder</summary>
Local,
/// <summary>Cloud, isolated folder. 100k cumulative limit.</summary>
Roaming,
/// <summary>Local, temporary folder (not for settings)</summary>
Temporary
}
你会这样称呼:
var _Exists = SettingExists("Sound", StorageStrategies.Roaming);
这取自我的StorageHelper:http://codepaste.net/gtu5mq
答案 2 :(得分:0)
也许您可以尝试编写这样的代码:
if(string.IsNullOrWhiteSpace(roamingSettings.Values["Sound"]))