android jni 用skia画图，运行后模拟器上没显示，求解啊_H5之家

本菜鸟最近在学习android jni skia画图，从网上找的例子，运行后模拟器上没有显示，不知道该怎么做。下面是我的代码：
java部分：
public class MainActivity extends Activity {
private native void code1(); //jni
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        code1();
    }
}
c++部分：
JNIEXPORT void JNICALL Java_com_pic_MainActivity_code1(JNIEnv* env,jobject obj)
{
LOGI("in good");
LOGI("in callcode1");
    SkBitmap bitmap;
    bitmap.setConfig(SkBitmap::kARGB_8888_Config,200,200);
    bitmap.allocPixels();
    SkCanvas canvas(new SkDevice(bitmap));
    SkPaint paint;
LOGI("in callcode2");
    // draw points with red.
    paint.setARGB(255, 255, 0, 0);
  //  paint.setStrokeWidth(4);
LOGI("in callcode3");
    canvas.drawPoint(40,30, paint);
    canvas.drawPoint(80,60, paint);
    canvas.drawPoint(120,90, paint);
LOGI("in callcode4");
SkRect r;
paint.setARGB(255, 255, 0, 0);
r.set(25, 25, 145, 145);
canvas.drawRect(r, paint);
    //draw a line with green.
    paint.setARGB(255, 0, 255, 0);
    paint.setStrokeWidth(4);
    canvas.drawLine(160,10,320,110,paint);
    //draw a circle with bule.
    paint.setARGB(255, 0, 0, 255);
    canvas.drawCircle(80,180,50,paint);
  //  canvas.setBitmapDevice(SkBitmap());
    LOGI("in callcode5");
    SkImageEncoder::EncodeFile("snapshot.png", bitmap,SkImageEncoder::kPNG_Type,100);

LOGI("out callcode1");
}

如果上面的代码是错误的，请给出一个完整的代码！！！

2012-11-09 14:01:39 whosyour_dady 楼主

1个回答

从java中传一个Bitmap到jni。
      DisplayMetrics metrics = new DisplayMetrics();    //获取分辨率大小
      this.getWindowManager().getDefaultDisplay().getMetrics(metrics);
      int width = metrics.widthPixels;
      int height = metrics.heightPixels;
       Bitmap dst=Bitmap.createBitmap(width, height, Config.ARGB_8888);//设置Bitmap的大小和颜色格式
        test(dst);  //把画布传过去
        ImageView  iv = new ImageView(this);
        iv.setImageBitmap(dst);
        setContentView(iv);
jni的接口中加上 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);
         。。。。画图。。。
       AndroidBitmap_unlockPixels(env, bitmap);

ok！！！

2012-11-12 11:11:36 goog_guzl 1楼