JNA 应用小结

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(1) char类型

? ? Java里的Char是双字节的,对应C的类型是wchar_t!要对应c的char类型可以用byte

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(2) 字符串处理

? ? const char*类型官方建议直接对应String类型,实际应用时对中文的编码问题老是处理不好!所以我这边用byte[]进行对应传入字符串时手工加个'\0',如:?

? ? str=str+"\0" ;fun(str.getBytes("Gb2312"));

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(3) 结构体处理

? ???结构体指针参数:

? ??typedef struct _Point {

  int x, y;} Point;Point* translate(Point* pt, int dx, int dy);

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? ?// Equivalent JNA mapping

class Point extends Structure { public int x, y; }Point translate(Point pt, int x, int y);...Point pt = new Point();Point result = translate(pt, 100, 100);

? ?结构体参数或结构体返回值

? ?typedef struct _Point {

  int x, y;} Point;Point translate(Point pt, int dx, int dy);

? ?// Equivalent JNA mapping

class Point extends Structure {    public static class ByValue extends Point implements Structure.ByValue { }    public int x, y;}Point.ByValue translate(Point.ByValue pt, int x, int y);...Point.ByValue pt = new Point.ByValue();Point result = translate(pt, 100, 100);

? ?结构体数组参数

? ?// Original C code

void get_devices(struct Device[], int size);

? ?// Equivalent JNA mapping

int size = ...Device[] devices = new Device[size];lib.get_devices(devices, devices.length);

? ? 返回结构体数组(指针)

? ??// Original C code

struct Display* get_displays(int* pcount);void free_displays(struct Display* displays);

? ?// Equivalent JNA mapping

Display get_displays(IntByReference pcount);void free_displays(Display[] displays);...IntByReference pcount = new IntByReference();Display d = lib.get_displays(pcount);Display[] displays = (Display[])d.toArray(pcount.getValue());...lib.free_displays(displays);

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JNA管方地址:?http://jna.java.net/

文档地址: ?http://jna.java.net/javadoc/overview-summary.html