[英]Marshal char[][LENGTH] in c#
在C#項目中,我很難連接來自外部庫的C ++函數。 我猜這是字符串編組的問題。
int compute(const char names[][LENGTH_1], char values[][LENGTH_2], const int n);
目標是提供:
函數“計算”將根據“名稱”中指定的內容寫入數組“值”。
[DllImport("abcd.dll", EntryPoint="compute", CharSet=CharSet.Ansi)]
internal static extern int Compute(StringBuilder [] names, StringBuilder [] values, int n);
我這樣稱呼它:
var names = new StringBuilder[number];
var descriptions = new StringBuilder[number];
for (int i = 0; i < number; i++) {
names[i] = new StringBuilder(LENGTH_1);
descriptions[i] = new StringBuilder(LENGTH_2);
}
var error = Compute(names, descriptions, number);
[StructLayout(LayoutKind.Sequential, CharSet=CharSet.Ansi, Pack=4)]
internal struct StringName
{
[MarshalAs(UnmanagedType.ByValTStr, SizeConst=64)] // LENGTH_1 = 64
public string msg;
}
[StructLayout(LayoutKind.Sequential, CharSet=CharSet.Ansi, Pack=4)]
internal struct StringValue
{
[MarshalAs(UnmanagedType.ByValTStr, SizeConst=128)] // LENGTH_2 = 128
public string msg;
}
[DllImport("abcd.dll", EntryPoint="compute", CharSet=CharSet.Ansi)]
internal static extern int Compute(StringName[] names, ref StringValue[] values, int number);
我這樣稱呼它:
var names = new StringNames[number];
var values = new StringValue[number];
var error = Compute(names, ref values, number);
它崩潰無一例外,該程序在“計算”功能上被阻止。 我仍然不確定問題是來自字符串還是來自外部庫。
大衛發現,關鍵字“ ref”是錯誤的。 這是方法2的更改。
[StructLayout(LayoutKind.Sequential, CharSet=CharSet.Ansi)]
internal struct StringName
{
[MarshalAs(UnmanagedType.ByValTStr, SizeConst=LENGTH_1)]
public string msg;
}
[StructLayout(LayoutKind.Sequential, CharSet=CharSet.Ansi)]
internal struct StringValue
{
[MarshalAs(UnmanagedType.ByValTStr, SizeConst=LENGTH_2)]
public string msg;
}
[DllImport("abcd.dll", EntryPoint="compute", CharSet=CharSet.Ansi)]
internal static extern int Compute([In] StringName[] names, [In, Out] StringValue[] values, int number);
我這樣稱呼它:
var names = new StringNames[number];
// ... here the initialization of "names" ... //
var values = new StringValue[number];
var error = Compute(names, values, number);
// ... here the processing of "values" ... //
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