关于C#：如何检查文件是否存在于Xamarin表单中

How to check if the file exist in xamarin forms

我想检查设备中的文件是否存在。当变量crphoto1为空或文件不存在时，"photo1"json应为{"Photo1",""}。

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JObject ph1json = string.IsNullOrEmpty(crphoto1)
? new JObject
{
{"ContactID", crcontactID},
{"Photo1",""}
}
: new JObject
{
{"ContactID", crcontactID},
{"Photo1", File.ReadAllBytes(crphoto1)}
};

相关讨论

如果您只是在寻找如何检查文件是否存在，您可以使用

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using System.IO;

string fileName = Path.Combine(Environment
.GetFolderPath(Environment.SpecialFolder.LocalApplicationData),"yourfile.jpg");

JObject ph1json;
bool doesExist = File.Exists(fileName);
if (!doesExist || string.IsNullOrEmpty(crphoto1))
{

ph1json = new JObject
{
{"ContactID",crcontactID},
{"Photo1",""}
};
}
else
{
ph1json = new JObject
{
{"ContactID",crcontactID},
{"Photo1",File.ReadAllBytes(crphoto1)}
};
}