问
直接从Delphi调用Android NDK功能的困难
可以通过JNI和NDK从Delphi调用Android C函数.实现这一点是相当多的工作,并建议直接调用NDK函数.为此,我创建了一个小的示例文件来沿着我在Delphi源代码中找到的行声明一个外部C函数.更具体的
我创建了一个非常小的测试程序来测试直接从Delphi调用C函数的功能.您将在下面找到所有源代码,这是我目前正在测试的内容.
unit DLL_external;
interface
const
MIDI_Lib = '/usr/lib/libmiditest.so';
test_fun = 'test_1';
function test_1 (n: Integer): Integer; cdecl;
external MIDI_Lib name test_fun;
implementation
initialization
finalization
end.
初始化和完成是必要的,因为否则会发生链接错误,指的是缺少初始化和终结代码.通话类:
unit DLL_Test_Main;
interface
uses
System.SysUtils, System.Types, System.UITypes, System.Classes, System.Variants,
FMX.Types, FMX.Controls, FMX.Forms, FMX.Graphics, FMX.Dialogs, FMX.StdCtrls,
DLL_external;
//{$I Androidapi.inc}
type
TForm1 = class(TForm)
Button_Load: TButton;
Label1: TLabel;
procedure Button_LoadClick (Sender: TObject);
procedure FormCreate(Sender: TObject);
public
procedure call_external_function (value: Integer);
end; // Class: TForm1 //
var
Form1: TForm1;
implementation
{$R *.fmx}
procedure TForm1.FormCreate (Sender: TObject);
begin
Label1.Text := 'External function not called yet';
end; // FormCreate //
procedure TForm1.Button_LoadClick (Sender: TObject);
begin
call_external_function (3);
end; // Button_LoadClick //
procedure TForm1.call_external_function (value: integer);
var n: Int32;
begin
n := test_1 (value);
Label1.Text := Format ('%d = test_1 (%d)', [n, value]);
end; // call_external_function //
end.
与本地图书馆一起miditest.这是建立使用ndk-build.生成的库libmiditest.so被复制到了,C:\Users\Public\Documents\RAD Studio\12.0\PlatformSDKs\android-ndk-r8e\platforms\android-14\arch-arm\usr\lib因为这是Delphi放置自己的库的地方.
#includeint test_1 (int n) // little test for callability { return n * n; }
当我这样做时,在子目录中生成ndk-build一个文件.我把这个文件复制到了.因为我在开始时有一些链接错误(错误的名称和那种愚蠢的错误)我曾经生成一个符号列表和库的预期架构.这个名字在符号列表中就像arm v7架构一样(我使用Nexus 7进行测试).当我运行Delphi程序时,它立即在Android上崩溃:"不幸的是,DLL_Test_Propject已停止".检查adb输出(见下文),看起来该文件是预期的.我将单元DLL_external 替换为并复制到.这没有用.libmiditest.solibs\armeabi-v7areadelf -AWs libmiditest.sotest_1libDLL_Test_Project.solibmiditest.solibDLL_Test_Project.so/usr/lib/libmiditest.so/usr/lib/libDLL_Test_Project.so
有谁知道为什么Delphi生成的应用程序试图加载自己的库？更好:任何建议如何通过Delphi调用Android C函数？
I/InputReader( 608): Reconfiguring input devices. changes=0x00000010
D/dalvikvm( 799): GC_FOR_ALLOC freed 2003K, 15% free 14582K/16964K, paused 29ms, total 29ms
I/PCKeyboard( 799): Loaded dictionary, len=841005
I/HK/LatinKeyboardBaseView( 799): onMeasure width=1200
I/HK/LatinKeyboardBaseView( 799): onMeasure width=1200
D/Documents( 3358): Used cached roots for com.android.providers.downloads.documents
D/Documents( 3358): Used cached roots for com.android.externalstorage.documents
D/Documents( 3358): Used cached roots for com.android.providers.media.documents
D/Documents( 3358): Used cached roots for com.google.android.apps.docs.storage
D/Documents( 3358): Update found 7 roots in 28ms
D/BackupManagerService( 608): Received broadcast Intent { act=android.intent.action.PACKAGE_ADDED dat=package:com.embarcadero.DLL_Test_Project flg=0x4000010 (has extras) }
V/BackupManagerService( 608): addPackageParticipantsLocked: #1
D/SystemBroadcastService( 987): Received broadcast action=android.intent.action.PACKAGE_ADDED and uri=
W/ContextImpl( 987): Implicit intents with startService are not safe: Intent { act=com.google.android.gms.games.service.INTENT } android.content.ContextWrapper.startService:494 com.google.android.gms.games.service.GamesIntentService.a:101 com.google.android.gms.games.service.GamesIntentService.b:368
I/ActivityManager( 608): Delay finish: com.android.vending/com.google.android.finsky.receivers.PackageMonitorReceiver$RegisteredReceiver
I/ActivityManager( 608): Resuming delayed broadcast
I/ActivityManager( 608): Delay finish: com.google.android.apps.plus/.service.PackagesMediaMonitor
I/ActivityManager( 608): Resuming delayed broadcast
V/GelStubAppWatcher( 3631): onReceive: android.intent.action.PACKAGE_ADDED
I/Icing.InternalIcingCorporaProvider( 3631): Updating corpora: A: com.embarcadero.DLL_Test_Project, C: MAYBE
I/ActivityManager( 608): START u0 {flg=0x10800000 cmp=com.estrongs.android.pop/.app.InstallMonitorActivity (has extras)} from pid 3466
D/dalvikvm( 608): GC_EXPLICIT freed 1385K, 11% free 19671K/22028K, paused 3ms+8ms, total 194ms
D/dalvikvm( 608): WAIT_FOR_CONCURRENT_GC blocked 24ms
D/AndroidRuntime( 4437): Shutting down VM
D/dalvikvm( 4437): GC_CONCURRENT freed 95K, 16% free 560K/660K, paused 0ms+0ms, total 2ms
W/InputMethodManagerService( 608): Window already focused, ignoring focus gain of: com.android.internal.view.IInputMethodClient$Stub$Proxy@42c98f48 attribute=null, token = android.os.BinderProxy@42b91f10
D/dalvikvm( 3631): GC_CONCURRENT freed 560K, 6% free 10268K/10860K, paused 2ms+2ms, total 23ms
D/AndroidRuntime( 4476):
D/AndroidRuntime( 4476): >>>>>> AndroidRuntime START com.android.internal.os.RuntimeInit <<<<<<
D/AndroidRuntime( 4476): CheckJNI is OFF
D/dalvikvm( 4476): Trying to load lib libjavacore.so 0x0
D/dalvikvm( 4476): Added shared lib libjavacore.so 0x0
D/dalvikvm( 4476): Trying to load lib libnativehelper.so 0x0
D/dalvikvm( 4476): Added shared lib libnativehelper.so 0x0
D/dalvikvm( 4476): No JNI_OnLoad found in libnativehelper.so 0x0, skipping init
D/dalvikvm( 4476): Note: class Landroid/app/ActivityManagerNative; has 179 unimplemented (abstract) methods
D/AndroidRuntime( 4476): Calling main entry com.android.commands.am.Am
I/ActivityManager( 608): START u0 {flg=0x10000000 cmp=com.embarcadero.DLL_Test_Project/com.embarcadero.firemonkey.FMXNativeActivity (has extras)} from pid 4476
D/dalvikvm( 608): GC_FOR_ALLOC freed 807K, 12% free 19517K/22028K, paused 63ms, total 63ms
D/AndroidRuntime( 4476): Shutting down VM
D/dalvikvm( 4476): GC_CONCURRENT freed 96K, 15% free 586K/684K, paused 0ms+0ms, total 2ms
D/dalvikvm( 4507): Late-enabling CheckJNI
I/ActivityManager( 608): Start proc com.embarcadero.DLL_Test_Project for activity com.embarcadero.DLL_Test_Project/com.embarcadero.firemonkey.FMXNativeActivity: pid=4507 uid=10113 gids={50113, 3003, 1028, 1015}
I/dalvikvm( 4507): Enabling JNI app bug workarounds for target SDK version 9...
V/PhoneStatusBar( 667): setLightsOn(true)
D/AndroidRuntime( 4507): Shutting down VM
W/dalvikvm( 4507): threadid=1: thread exiting with uncaught exception (group=0x41ccbba8)
E/AndroidRuntime( 4507): FATAL EXCEPTION: main
E/AndroidRuntime( 4507): Process: com.embarcadero.DLL_Test_Project, PID: 4507
E/AndroidRuntime( 4507): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.embarcadero.DLL_Test_Project/com.embarcadero.firemonkey.FMXNativ
eActivity}: java.lang.IllegalArgumentException: Unable to load native library: /data/app-lib/com.embarcadero.DLL_Test_Project-1/libDLL_Test_Project.so
E/AndroidRuntime( 4507): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2195)
E/AndroidRuntime( 4507): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245)
E/AndroidRuntime( 4507): at android.app.ActivityThread.access$800(ActivityThread.java:135)
E/AndroidRuntime( 4507): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
E/AndroidRuntime( 4507): at android.os.Handler.dispatchMessage(Handler.java:102)
E/AndroidRuntime( 4507): at android.os.Looper.loop(Looper.java:136)
E/AndroidRuntime( 4507): at android.app.ActivityThread.main(ActivityThread.java:5017)
E/AndroidRuntime( 4507): at java.lang.reflect.Method.invokeNative(Native Method)
E/AndroidRuntime( 4507): at java.lang.reflect.Method.invoke(Method.java:515)
E/AndroidRuntime( 4507): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
E/AndroidRuntime( 4507): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
E/AndroidRuntime( 4507): at dalvik.system.NativeStart.main(Native Method)
E/AndroidRuntime( 4507): Caused by: java.lang.IllegalArgumentException: Unable to load native library: /data/app-lib/com.embarcadero.DLL_Test_Project-1/libDLL_Test_Project.so
E/AndroidRuntime( 4507): at android.app.NativeActivity.onCreate(NativeActivity.java:183)
E/AndroidRuntime( 4507): at com.embarcadero.firemonkey.FMXNativeActivity.onCreate(FMXNativeActivity.java:67)
E/AndroidRuntime( 4507): at android.app.Activity.performCreate(Activity.java:5231)
E/AndroidRuntime( 4507): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
E/AndroidRuntime( 4507): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2159)
E/AndroidRuntime( 4507): ... 11 more
W/ActivityManager( 608): Force finishing activity com.embarcadero.DLL_Test_Project/com.embarcadero.firemonkey.FMXNativeActivity
I/WindowManager( 608): Screenshot max retries 4 of Token{42a06c48 ActivityRecord{42a42de8 u0 com.embarcadero.DLL_Test_Project/com.embarcadero.firemonkey.FMXNat
iveActivity t17 f}} appWin=Window{42a1bab8 u0 Starting com.embarcadero.DLL_Test_Project} drawState=4
W/WindowManager( 608): Screenshot failure taking screenshot for (1200x1920) to layer 21015
W/ActivityManager( 608): Activity pause timeout for ActivityRecord{42a42de8 u0 com.embarcadero.DLL_Test_Project/com.embarcadero.firemonkey.FMXNativeActivity t17 f}
E/WindowManager( 608): Starting window AppWindowToken{4308ff58 token=Token{42a06c48 ActivityRecord{42a42de8 u0 com.embarcadero.DLL_Test_Project/com.embarcadero.firemonkey.FMXNativeActivity t17}}} timed out
I/Process ( 4507): Sending signal. PID: 4507 SIG: 9
W/InputMethodManagerService( 608): Window already focused, ignoring focus gain of: com.android.internal.view.IInputMethodClient$Stub$Proxy@42a1abd0 attribute=null, token = android.os.BinderProxy@42b91f10
I/ActivityManager( 608): Process com.embarcadero.DLL_Test_Project (pid 4507) has died.
D/Finsky ( 1567): [1] 5.onFinished: Installation state replication succeeded.
更新1
从我收集的评论中,代码可能是更大系统的一部分.此代码是一个小型独立程序.本机代码库确实和您在此处看到的一样小.
更新2
正如Arioch所指出的那样,通过使用静态链接(或Windows术语中的隐式加载),主程序将在库未加载时加载.这解释了adb上面提到的消息.因此,问题是:为什么libmiditest.so没有加载？
撰写答案
今天，你开发时遇到什么问题呢？
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