我有一个c++文件的以下代码，用于限制JFrame从Java调整大小超过一定大小。但是当我编译代码时，我得到4个关于将jint转换为更大尺寸的HWND的警告，然后我得到4个错误LNK2019: unresolved external symbol并且这些错误似乎是指使用的整数在功能; setMinMaxResizeBoundaries()和getComponentHWND()。
DllMain.cpp
//For JNI
#include <jni.h>
#include <jawt.h>
#include <jawt_md.h>
//Rest
#include <stdio.h>
#include <windows.h>
//My File
#include "JNITest.h"
// Global variables defined in DllMain.cpp
// Used for setMinMaxResizeBoundaries()
struct SHwndMinMax
{
HWND hwnd;
int minWidth;
int minHeight;
int maxWidth;
int maxHeight;
WNDPROC prefWndProc;
};
SHwndMinMax gsHwndMinMax[2048];
int gsHwndMinMaxCount = 0;
LRESULT CALLBACK MinMaxWindowProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam);
// Code added somwhere:
// setMinMaxResizeBoundaries()
// Sets the resize boundary window sizes, so the window will not be resized above/below that size
JNIEXPORT jint JNICALL Java_JNITest_setMinMaxResizeBoundaries(JNIEnv* env, jclass cls,
jint hwnd,
jint minWidth, jint minHeight,
jint maxWidth, jint maxHeight)
{
// We create a hook for the window, and intercept the WM_GETMINMAXINFO message occurs, and update the info
if (IsWindow((HWND)hwnd))
{ // Let's add it
if (gsHwndMinMaxCount < 2048)
{ // We're good
// Can add code here to check if this option is valid or not--so it can later be "unhooked" by a separate function call
gsHwndMinMax[gsHwndMinMaxCount].hwnd = (HWND)hwnd;
gsHwndMinMax[gsHwndMinMaxCount].minWidth = minWidth;
gsHwndMinMax[gsHwndMinMaxCount].minHeight = minHeight;
gsHwndMinMax[gsHwndMinMaxCount].maxWidth = maxWidth;
gsHwndMinMax[gsHwndMinMaxCount].maxHeight = maxHeight;
gsHwndMinMax[gsHwndMinMaxCount].prefWndProc = (WNDPROC)SetWindowLongPtr((HWND)hwnd, GWLP_WNDPROC, (LONG_PTR)&MinMaxWindowProc);
// Success
++gsHwndMinMaxCount;
return(0);
} else {
// Failuire, too many hooks
return(-2);
}
} else {
// Failure, HWND is not valid
return(-1);
}
}
LRESULT CALLBACK MinMaxWindowProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
int i;
MINMAXINFO* mmi;
for (i = 0; i < gsHwndMinMaxCount; i++)
{
if (hwnd == gsHwndMinMax[i].hwnd)
{ // This is our man, see if it's our message
if (msg == WM_GETMINMAXINFO)
{ // It is
// When maximized, window is at upper-left
mmi = (MINMAXINFO*)lParam;
mmi->ptMaxSize.x = gsHwndMinMax[i].maxWidth;
mmi->ptMaxSize.y = gsHwndMinMax[i].maxHeight;
mmi->ptMaxPosition.x = 0; // Can add code here to properly position the window centered in the screen, etc.
mmi->ptMaxPosition.y = 0; // Same here
// Set the minimum and maximum tracking size (when the user is resizing, what's the smallest and biggest window they see)
mmi->ptMinTrackSize.x = gsHwndMinMax[i].minWidth;
mmi->ptMinTrackSize.y = gsHwndMinMax[i].minHeight;
mmi->ptMaxTrackSize.x = gsHwndMinMax[i].maxWidth;
mmi->ptMaxTrackSize.y = gsHwndMinMax[i].maxHeight;
return(DefWindowProc(hwnd, msg, wParam, lParam));
} else {
// Nope, pass it on
return(CallWindowProc(gsHwndMinMax[i].prefWndProc, hwnd, msg, wParam, lParam));
}
}
}
return(0);
}
// getComponentHWND()
// Called to return the HWND of the component, if it has one.
JNIEXPORT jint JNICALL Java_JNITest_getComponentHWND(JNIEnv* env, jclass cls, jobject obj)
{
HWND hWnd = 0;
typedef jboolean (JNICALL *PJAWT_GETAWT)(JNIEnv*, JAWT*);
JAWT awt;
JAWT_DrawingSurface* ds;
JAWT_DrawingSurfaceInfo* dsi;
JAWT_Win32DrawingSurfaceInfo* dsi_win;
jboolean result;
jint lock;
HMODULE _hAWT = 0;
// Load AWT Library
if (!_hAWT)
_hAWT = LoadLibrary("jawt.dll"); // for Java 1.4+
if (_hAWT)
{
PJAWT_GETAWT JAWT_GetAWT = (PJAWT_GETAWT)GetProcAddress(_hAWT, "JAWT_GetAWT");
if (JAWT_GetAWT)
{
awt.version = JAWT_VERSION_1_4; // Init here with JAWT_VERSION_1_3 or JAWT_VERSION_1_4
// Get AWT API Interface
result = JAWT_GetAWT(env, &awt);
if (result != JNI_FALSE)
{
ds = awt.GetDrawingSurface(env, obj);
if (ds != NULL)
{
lock = ds->Lock(ds);
if ((lock & JAWT_LOCK_ERROR) == 0)
{
dsi = ds->GetDrawingSurfaceInfo(ds);
if (dsi)
{
dsi_win = (JAWT_Win32DrawingSurfaceInfo*)dsi->platformInfo;
if (dsi_win)
hWnd = dsi_win->hwnd;
else
hWnd = (HWND) -1; // Failed to obtain the handle (not running on Windows)
ds->FreeDrawingSurfaceInfo(dsi);
} else {
hWnd = (HWND)-2; // Failed to get the drawing surface info block
}
ds->Unlock(ds);
} else {
hWnd = (HWND)-3; // Failed to lock the drawing surface to obtain information about it
}
awt.FreeDrawingSurface(ds);
} else {
hWnd = (HWND)-4; // Failed to get the drawing surface from the compoment
}
} else {
hWnd = (HWND)-5; // Failed to obtain a proper result from _JAWT_GetAWT()
}
} else {
hWnd = (HWND)-6; // Failed to find "_JAWT_GetAWT()" function
}
} else {
hWnd = (HWND)-7; // Failed to load awt.dll
}
return (jint)hWnd;
}
编译器输出
DllMain.cpp
DllMain.cpp(38): warning C4312: 'type cast': conversion from 'jint' to 'HWND' of greater size
DllMain.cpp(43): warning C4312: 'type cast': conversion from 'jint' to 'HWND' of greater size
DllMain.cpp(48): warning C4312: 'type cast': conversion from 'jint' to 'HWND' of greater size
DllMain.cpp(164): warning C4311: 'type cast': pointer truncation from 'HWND' to 'jint'
Microsoft (R) Incremental Linker Version 14.00.24210.0
Copyright (C) Microsoft Corporation. All rights reserved.
/dll
/implib:DllMain64.lib
/out:DllMain64.dll
DllMain.obj
Creating library DllMain64.lib and object DllMain64.exp
DllMain.obj : error LNK2019: unresolved external symbol __imp_DefWindowProcA referenced in function "__int64 __cdecl MinMaxWindowProc(struct HWND__ *,unsigned int,unsigned __int64,__int64)" (?MinMaxWindowProc@@YA_JPEAUHWND__@@I_K_J@Z)
DllMain.obj : error LNK2019: unresolved external symbol __imp_CallWindowProcA referenced in function "__int64 __cdecl MinMaxWindowProc(struct HWND__ *,unsigned int,unsigned __int64,__int64)" (?MinMaxWindowProc@@YA_JPEAUHWND__@@I_K_J@Z)
DllMain.obj : error LNK2019: unresolved external symbol __imp_IsWindow referenced in function Java_JNITest_setMinMaxResizeBoundaries
DllMain.obj : error LNK2019: unresolved external symbol __imp_SetWindowLongPtrA referenced in function Java_JNITest_setMinMaxResizeBoundaries
DllMain64.dll : fatal error LNK1120: 4 unresolved externals
感谢您解决问题的任何帮助
编译批次
call "C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\vcvarsall.bat" amd64
javac JNITest.java
javah -jni JNITest
cl -I"C:/Program Files (x86)/Java/jdk1.8.0_92/include" -I"C:/Program Files (x86)/Java/jdk1.8.0_92/include/win32" -MD -LD DllMain.cpp -FeDllMain64.dll
pause