标签：c ios xamarin-ios xamarin marshalling
我想研究如何绑定iOS库与处理指向Xamarin.iOS的指针.
它需要编组.
我准备这样的库进行测试,
MarshalTest.h
typedef struct
{
float x,y,z;
} Marshal3D;
@interface MarshalTest : NSObject
-(id)initWithMarshal:(Marshal3D *)marshal;
-(id)initWithMarshals:(Marshal3D *)marshals num:(int)numCoord;
-(void)addMarshal:(Marshal3D *)marshal;
-(void)addMarshals:(Marshal3D *)marshals num:(int)numCoord;
-(int)getMarshals:(Marshal3D **)getMarshals;
-(int) storedNumber;
-(float)checkMarshalValue:(int)index xyz:(int)xyz;
@end
并准备绑定c#代码,如下所示：
StructsAndEnums.cs
using System;
using System.Runtime.InteropServices;
namespace MarshalTestNet
{
[StructLayout(LayoutKind.Sequential)]
public struct Marshal3D
{
public float x;
public float y;
public float z;
};
}
ApiDefinition.cs
using System;
using System.Drawing;
using System.Runtime.InteropServices;
using MonoTouch.ObjCRuntime;
using MonoTouch.Foundation;
using MonoTouch.UIKit;
namespace MarshalTestNet
{
[BaseType (typeof (NSObject))]
public partial interface MarshalTest {
[Export ("initWithMarshal:")]
IntPtr Constructor ([In, MarshalAs(UnmanagedType.LPStruct)]Marshal3D marshal);
[Export ("initWithMarshals:num:")]
IntPtr Constructor ([In, MarshalAs(UnmanagedType.LPStruct)]Marshal3D marshals, int numCoord);
[Export ("addMarshal:")]
void AddMarshal ([In, MarshalAs(UnmanagedType.LPStruct)]Marshal3D marshal);
[Export ("addMarshals:num:")]
void AddMarshals ([In, MarshalAs(UnmanagedType.LPStruct)]Marshal3D marshals, int numCoord);
[Export ("getMarshals:")]
int GetMarshals ([Out, MarshalAs(UnmanagedType.LPStruct)]Marshal3D getMarshals);
[Export ("storedNumber")]//, Verify ("ObjC method massaged into getter property", "/Users/kokogiko/Desktop/MarshalTest.h", Line = 32)]
int StoredNumber { get; }
[Export ("checkMarshalValue:xyz:")]
float CheckMarshalValue (int index, int xyz);
}
}
但这不起作用,只是打电话
var mars3 = new Marshal3D{
x = 1.0f,
y = 2.0f,
z = 3.0f
};
var mars = new MarshalTest (mars3);
将终止而不显示错误消息.
如何将iOS库与编组绑定？
这样做的信息非常少……
[罗尔夫回答后编辑]
谢谢Rolf,我测试了很多案例,很抱歉这么晚回复.
1.
[Export ("initWithMarshal:")]
IntPtr Constructor (ref Marshal3D marshal);
[Export ("addMarshal:")]
void AddMarshal (ref Marshal3D marshal);
效果很好.谢谢！
2.
[Export ("initWithMarshals:num:")]
IntPtr Constructor (Marshal3D[] marshals, int numCoord);
[Export ("addMarshals:num:")]
void AddMarshals (Marshal3D[] marshals, int numCoord);
不起作用,在编译阶段显示此错误：
obj/Debug/ios/MarshalTestNet/MarshalTest.g.cs(140,31): error CS1502: The best overloaded method match for `MonoTouch.Foundation.NSArray.FromNSObjects(params MonoTouch.Foundation.NSObject[])' has some invalid arguments
/Developer/MonoTouch/usr/lib/mono/2.1/monotouch.dll (Location of the symbol related to previous error)
obj/Debug/ios/MarshalTestNet/MarshalTest.g.cs(140,46): error CS1503: Argument `#1' cannot convert `MarshalTestNet.Marshal3D[]' expression to type `MonoTouch.Foundation.NSObject[]'
所以我自己改变了,
ApiDefinition.cs
[Export ("addMarshals:num:")]
void AddMarshals (IntPtr marshals, int numCoord);
Extra.cs
public unsafe void AddMarshals (Marshal3D[] marshals) {
var count = marshals.Length;
fixed (Marshal3D* ptr = &marshals[0])
AddMarshals ((IntPtr)ptr, count);
}
这很好用.
但是,这种方法不能用于
-(id)initWithMarshals:(Marshal3D *)marshals num:(int)numCoord;
因为它是构造函数,在调用父方法之前不允许添加任何逻辑.
有没有什么办法解决这一问题？
使用“工厂模式”最好？
3.
[Export ("getMarshals:")]
[Internal]
int GetMarshals (IntPtr getMarshals);
和
public partial class MarshalTest : NSObject {
public unsafe Marshal3D [] GetMarshals () {
var count = this.StoredNumber();
var array = new Marshal3D [count];
fixed (Marshal3D* ptr = &array[0])
GetMarshals ((IntPtr) ptr);
return array;
}
}
不行.
终止时没有在runnig阶段显示任何错误.
我认为
Marshal3D* ptr = &array[0]
是指针,但是
-(int)getMarshals:(Marshal3D **)getMarshals;
需要指针指针.
不是吗？
解决方法:
Xamarin.iOS绑定项目不支持自定义编组.
但我认为你不需要它：
[BaseType (typeof (NSObject))]
public partial interface MarshalTest {
[Export ("initWithMarshal:")]
IntPtr Constructor (ref Marshal3D marshal);
[Export ("initWithMarshals:num:")]
IntPtr Constructor (Marshal3D[] marshals, int numCoord);
[Export ("addMarshal:")]
void AddMarshal (ref Marshal3D marshal);
[Export ("addMarshals:num:")]
void AddMarshals (Marshal3D[] marshals, int numCoord);
[Export ("getMarshals:")]
[Internal]
int GetMarshals (IntPtr getMarshals);
// ...
}
但是,为了很好地支持GetMarshals,您必须添加自定义绑定(这通常在StructsAndEnums.cs文件中完成)：
public partial class MarshalTest : NSObject {
public unsafe Marshal3D [] GetMarshals () {
var count = // how many are there? there's no API to fetch this in your sample
var array = new Marshal3D [count];
fixed (Marshal3D* ptr = &array[0])
GetMarshals ((IntPtr) ptr);
return array;
}
}
[更新以回答第二组问题]
>对于构造函数,我认为这将起作用：
ApiDefinition.cs
[BaseType (typeof (NSObject))]
public partial interface MarshalTest {
[Export ("initWithMarshals:num:")]
[Internal]
IntPtr Constructor (IntPtr marshals, int numCoord);
}
Extra.cs
public partial class MarshalTest : NSObject {
public MarshalTest (Marshal3D[] marshals, int numCoord)
: this (GetPointer (marshals), numCoord)
{
}
static IntPtr GetPointer (Marshal3D[] marshals)
{
fixed (Marshal3D* ptr = &marshals[0])
return (IntPtr) ptr;
}
}
>你是对的,它期待一个指向数组的指针.试试这个：
ApiDefinition.cs
[BaseType (typeof (NSObject))]
public partial interface MarshalTest {
[Export ("getMarshals:")]
[Internal]
int GetMarshals (ref IntPtr getMarshals);
}
Extra.cs
public partial class MarshalTest : NSObject {
public unsafe Marshal3D [] GetMarshals () {
var ptr = IntPtr.Zero;
var count = this.StoredNumber ();
var array = new Marshal3D [count];
GetMarshals (ref ptr);
unsafe {
Marshal3D* ptr3d = (Marshal3D *) ptr;
for (int i = 0; i < count; i++)
array [i] = *ptr3d++;
}
return array;
}
}
标签：c,ios,xamarin-ios,xamarin,marshalling 来源： https://codeday.me/bug/20190517/1119793.html
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