JNI:封装Android中Canvas类下的drawBitmap()函数问题请教!

[Begodya]

请教:
画位图在Android下实现方法为:

	 // 从资源文件中生成位图 
	 Bitmap bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.icon); 
	 // 绘图 
	 canvas.drawBitmap(bitmap, 10, 10, paint); 

现要用JNI封装Android中Canvas类下的drawBitmap(Bitmap bitmap, float left, float top, Paint paint) 函数;

//位图
jobject CVMAndroidDC::GetResources()
{
	static jmethodID jmidGetResources=NULL;
	if(jmidGetResources==NULL)
	{
		jclass jclsView=m_pJNIEnv->FindClass("android/view/View");	
		jmidGetResources=m_pJNIEnv->GetMethodID(jclsView, "getResources", "()Landroid/content/res/Resources;");

		m_pJNIEnv->DeleteLocalRef(jclsView);      //回收
	}
	return m_pJNIEnv->CallObjectMethod(m_jobjView, jmidGetResources);         //return -> Resources 
}

//问题主要出在这一DecodeResource()函数的封装,---->LOG提示,GetMethodID:method not found:decodeResource(Landroid/content/res/Resources;I)Landroid/graphics/Bitmap;)

jobject CVMAndroidDC::DecodeResource(int id)
{
	GetResources();
	
	static jmethodID jmidDecodeResource=NULL;
	if(jmidDecodeResource==NULL)
	{
		jclass jclsBitmapFactory=m_pJNIEnv->FindClass("android/graphics/BitmapFactory");
		jmidDecodeResource=m_pJNIEnv->GetMethodID(jclsBitmapFactory, "decodeResource", "(Landroid/content/res/Resources;I)Landroid/graphics/Bitmap;");
		
		m_pJNIEnv->DeleteLocalRef(jclsBitmapFactory);    //回收
	}
/*    return m_pJNIEnv->CallStaticObjectMethod(m_jobjBitmapFactory, jmidDecodeResource, m_jobjView, id);    
     当调用CallStaticObjectMethod时Eclipse会提示error: invalid conversion from '_jobject*' to '_jclass*'
*/
   return m_pJNIEnv->CallObjectMethod(m_jobjBitmapFactory, jmidDecodeResource, m_jobjView, id);    //return ->Static Bitmap
}


VOID CVMAndroidDC::DrawBitmap(int left, int top)
{
	static jmethodID jmidDrawBitmap=NULL;
	if(jmidDrawBitmap==NULL)
	{
		jclass jclsCanvas=m_pJNIEnv->FindClass("android/graphics/Canvas");
		jmidDrawBitmap=m_pJNIEnv->GetMethodID(jclsCanvas, "drawBitmap", "(Landroid/graphics/Bitmap;FFLandroid/graphics/Paint;)V");
		m_pJNIEnv->DeleteLocalRef(jclsCanvas);          //回收
	}
	m_pJNIEnv->CallVoidMethod(m_jobjCanvas, jmidDrawBitmap, m_jobjBitmapFactory, (jfloat)left, (jfloat)top, m_jobjPaint);
}

[Begodya]

jmidDecodeResource=m_pJNIEnv->GetStaticMethodID(jclsBitmapFactory, "decodeResource", "(Landroid/content/res$Resources;I)Landroid/graphics/Bitmap;");

return m_pJNIEnv->CallStaticObjectMethod(m_jobjBitmapFactory, jmidDecodeResource, m_jobjView, id);    

[javacn_org]

ddddd

[Begodya]

将Resources res=this.getResources();===>Returns the resources associated with this view.
封装如下:

jobject CVMAndroidDC::GetResources()
{
	static jmethodID jmidGetResources=NULL;
	if(jmidGetResources==NULL)
	{
		jclass jclsView=m_pJNIEnv->FindClass("android/view/View");	
		jmidGetResources=m_pJNIEnv->GetMethodID(jclsView, "getResources", "()Landroid/content/res/Resources;");

		m_pJNIEnv->DeleteLocalRef(jclsView);        //回收
	}
	res = m_pJNIEnv->CallObjectMethod(m_jobjView, jmidGetResources);       
	
	if(res==NULL)   //问题=====> getResources()返回资源为空,因为只是单纯的调用getResources()函数,并没用指定获取的是具体哪个对象的资源;   
		TRACE("res is NULL!!!\n");
	
	return res;
}

[Begodya]

问题已解决。

[xqhrs232]

不知道楼主怎么解决的！！！