Skia是Android的底層的圖形庫(kù)，最近看了一下參考了了網(wǎng)上的例子最初是這樣做的就是從上層直接傳一個(gè)Canvas再在底層獲取它

運(yùn)行的時(shí)候老是不成功，不過(guò)可以畫(huà)圖形，比如線(xiàn)、矩形等，最后在網(wǎng)上查了一下，大致是源代碼版本和庫(kù)不同導(dǎo)致的最后實(shí)在沒(méi)法了，我就直接傳一個(gè)Bitmap對(duì)象，再在底層

將文字和圖形寫(xiě)在上面，這樣就可以了

下面是底層代碼:

#include "SkRect.h"

#include "SkImageEncoder.h"

static JNIEnv *env=NULL;

static int nMethods=1;

const char* classname="mytest/com/sam/NativeMethods";

extern "C"

{

void jni_renderhello(JNIEnv *env,jobject ob,jobject bitmap);

};

static JNINativeMethod gMethods[] = {

{

"test","(Landroid/graphics/Bitmap;)V",(void *)jni_renderhello

},

};

void jni_renderhello(JNIEnv * env, jobject obj, jobject bitmap)

{

AndroidBitmapInfo info;

int* pixels;

int ret;

ret = AndroidBitmap_getInfo(env, bitmap, &info);

ret = AndroidBitmap_lockPixels(env, bitmap, (void**)&pixels);

int width=(int)info.width;

int height=(int)info.height;

SkBitmap bmp = SkBitmap();

bmp.setConfig(SkBitmap::kARGB_8888_Config,width,height,0);

bmp.setPixels((void*)pixels);

SkCanvas backgroud(bmp);

SkPaint paint;

paint.setColor(SK_ColorGRAY);

SkRect rect;

rect.set(0,0,width,height);

backgroud.drawRect(rect,paint);

paint.setColor(SK_ColorGREEN);

const char *str="Hello Skia";

paint.setTextSize(30);

backgroud.drawText(str,strlen(str), 0, 100 , paint);

}

jint JNI_OnLoad(JavaVM* vm, void* reserved)

{

jint result=-1;

jclass clz=NULL;

if(vm->GetEnv((void**)&env,JNI_VERSION_1_4)!=JNI_OK)

return -1;

clz=env->FindClass(classname);

if(env->RegisterNatives(clz,gMethods,nMethods)<0)

return -1;

return JNI_VERSION_1_4;

}

這是java的調(diào)用

public class MyTestActivity extends Activity {

/** Called when the activity is first created. */

MyView view;

@Override

public void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

view=new MyView(this);

setContentView(view);

}

}

class MyView extends View

{

public MyView(Context context) {

super(context);

// TODO Auto-generated constructor stub

}

@Override

protected void onDraw(Canvas canvas) {

// TODO Auto-generated method stub

super.onDraw(canvas);

NativeMethods method=new NativeMethods();

Bitmap bm=Bitmap.createBitmap(canvas.getWidth(),canvas.getHeight(), Config.ARGB_8888);

final Paint paint = new Paint();

method.test(bm);

canvas.drawBitmap(bm, 0, 0, paint);

}

}

class NativeMethods

{

public native void test(Bitmap canvas);

static

{

System.loadLibrary("Skiademo");

}

}

總結(jié)

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