我想研究如何将 iOS 库与指向 Xamarin.iOS 的处理指针绑定(bind)。 它需要编码。
我为测试准备了这样的库,
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
并像这样准备绑定(bind) C# 代码:
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);
}
}
但这行不通,只是调用
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。
如何通过编码绑定(bind) iOS 库? 执行此操作的信息非常少......
[根据 Rolf 的回答进行编辑]
谢谢 Rolf,我测试了很多案例,很抱歉这么晚才回复。
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);
}
这很有效。
但是,这种方法不能用于
-(id)initWithMarshals:(Marshal3D *)marshals num:(int)numCoord;
因为是构造函数,所以在调用父方法之前不允许添加任何逻辑。
有什么办法可以解决这个问题吗?
使用“工厂模式”是最好的?
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;
}
}
无效。
在运行阶段未显示任何错误而终止。
我觉得
Marshal3D* ptr = &array[0]
是一个指针,但是
-(int)getMarshals:(Marshal3D **)getMarshals;
需要指针中的指针。
对不对?
最佳答案
Xamarin.iOS 绑定(bind)项目不支持自定义编码。
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);
// ...
}
然而,为了很好地支持 GetMarshals,您必须添加自定义绑定(bind)(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;
}
}
[已更新以回答第二组问题]
对于构造函数,我认为这会起作用:
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; }
没错,它需要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; } }
关于c# - 如何使用编码绑定(bind) Xamarin iOS Obj-C 库,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/23665042/