如何在Java中创建对象列表

Question

我有一个名为MarkerCustom的类文件。MarkerCustom有一个构造函数，它接受三个不同类型的变量。

public MarkerCustom(int myInt, String, myString, BitmapData myBitmap) {

从我的main Main活动中，我希望加载一个GLSurface视图，该视图将获取MarkerCustom的每个实例的ArrayList，我希望将这些实例与将传递给MarkerCustom的构造函数的每个实例的数据一起加载到GLSurface中。

让我们调用数组列表myMarkers；

我需要myMarkers看起来像这样：

myMarkers[0] = [1, "hello", bitMapData1]
myMarkers[1] = [66, "johnHandy", bitmapData2]

我对java相当陌生，它的铸造等让我有点困惑，因为来自AS3

编辑

因此，按照AKhill在下面的答案，我编辑了我的GL表面视图以接受如下所示的数组列表。但是，需要从构造函数中该 ArrayList 中列出的每个类创建标记自定义类，其方式使其可在 GLSurFaceView 的“曲面创建”和“绘制框架”方法中访问。

请参阅下面的此类方法和 for 循环/注释：

public class GLLayer extends GLSurfaceView implements SurfaceHolder.Callback, Camera.PreviewCallback, Renderer {

    private Context context;

    ArrayList <MarkerCustom> locationTags;

    private PhoneOrientation phoneOri;


    public GLLayer(Context context, int orientation, ArrayList<MarkerCustom> custMarkers) {
        super(context);
        locationTags = custMarkers;

        this.context = context;

        phoneOri=new PhoneOrientation(context); // sensor manager and interpreter

         for(int i =0; i<locationTags.size(); i++){

            //Need to create a an instance of each MarkerCustom
            // something like MarkerCustom locationTags[i]; = new MarkerCustom (its params);
        }
        this.setEGLConfigChooser(8, 8, 8, 8, 16, 0);
        this.getHolder().setFormat(PixelFormat.TRANSLUCENT);

        this.setRenderer(this);
        phoneOri.start(context, orientation);

    }

    @Override
    public void onDrawFrame(GL10 gl) {
        gl.glEnable(GL10.GL_TEXTURE_2D);

        gl.glClear(GL10.GL_COLOR_BUFFER_BIT | GL10.GL_DEPTH_BUFFER_BIT);

        gl.glLoadIdentity();

        GLU.gluLookAt(gl,0, 0, 0, 0, 0, 0, 0, 0, 0);

        float floatMat[]=phoneOri.getMatrix();

        gl.glMatrixMode(GL10.GL_MODELVIEW);


        gl.glLoadMatrixf(floatMat, 0);


        for(int i=0;i<loacationTags.size();i++){
            gl.glPushMatrix();

            //locationTags[i].draw(gl);
            gl.glLoadMatrixf(floatMat,0);
        }


         gl.glPushMatrix();

    }

    @Override
    public void onSurfaceChanged(GL10 gl, int width, int height) {
      if(height == 0) {                    
        height = 1;                         
        }
        float ratio = (float) width / height;
        gl.glViewport(0, 0, width, height);     
        gl.glMatrixMode(GL10.GL_PROJECTION);    
        gl.glLoadIdentity();                    

        GLU.gluPerspective(gl, 35.0f, (float)width / (float)height, 5.0f, 200.0f);
        gl.glMatrixMode(GL10.GL_MODELVIEW);     
        gl.glLoadIdentity();                    

        GLU.gluLookAt(gl, 0, 1.0f, 5.0f, 0, 0, 0, 0, 1.0f, 0);


    }

    @Override
    public void onSurfaceCreated(GL10 gl, EGLConfig arg1) {

        for(int i=0;i<locationTags.size();i++){
            //call each MarkerCustom's loadGLTexture Method
                //locationTags[i].loadGLTexture(gl, this.context);
        }


        gl.glEnable(GL10.GL_TEXTURE_2D);            
        gl.glShadeModel(GL10.GL_SMOOTH);            
        gl.glClearColor(0.0f, 0.0f, 0.0f, 0.0f);    
        gl.glClearDepthf(1.0f);                     
        gl.glEnable(GL10.GL_DEPTH_TEST);           
        gl.glDepthFunc(GL10.GL_LEQUAL);             


        gl.glHint(GL10.GL_PERSPECTIVE_CORRECTION_HINT, GL10.GL_SMOOTH);

    }

    @Override
    public void onPreviewFrame(byte[] data, Camera camera) {


    }


}

这里仅供参考的是我的< code>MarkerCustom类

public class MarkerCustom {

    public float xPos;
    public float yPos;
    public float zPos;
    public float yaw;
    public float pitch;
    public Bitmap tagImage;

    private FloatBuffer vertexBuffer;   // buffer holding the vertices
    private float vertices[] = {
            0.0f, -10.0f, -10.0f,        // V1 - bottom left
            0.0f, -10.0f, 10.0f,        // V2 - top left
            0.0f, 10.0f, -10.0f,        // V3 - bottom right
            0.0f, 10.0f, 10.0f         // V4 - top right

    };

    private FloatBuffer textureBuffer;  // buffer holding the texture coordinates
    private float texture[] = {
            // Mapping coordinates for the vertices
            0.0f, 1.0f,     // top left     (V2)
            0.0f, 0.0f,     // bottom left  (V1)
            1.0f, 1.0f,     // top right    (V4)
            1.0f, 0.0f      // bottom right (V3)

    };


    public MarkerCustom(float x, float y, float z, float yawAngle, float pitchAngle, Bitmap bitmap) {

        xPos = x;
        yPos = y;
        zPos = z;
        yaw = yawAngle;
        pitch = pitchAngle;
        tagImage = bitmap;

        ByteBuffer byteBuffer = ByteBuffer.allocateDirect(vertices.length * 4);
        byteBuffer.order(ByteOrder.nativeOrder());
        vertexBuffer = byteBuffer.asFloatBuffer();
        vertexBuffer.put(vertices);
        vertexBuffer.position(0);

        byteBuffer = ByteBuffer.allocateDirect(texture.length * 4);
        byteBuffer.order(ByteOrder.nativeOrder());
        textureBuffer = byteBuffer.asFloatBuffer();
        textureBuffer.put(texture);
        textureBuffer.position(0);

    }
    /** The texture pointer */
    private int[] textures = new int[1];

    public void loadGLTexture(GL10 gl, Context context) {
        // loading texture
        // Enable blending using premultiplied alpha.
        gl.glEnable(GL10.GL_BLEND);
        gl.glBlendFunc(GL10.GL_ONE, GL10.GL_ONE_MINUS_SRC_ALPHA);



        // generate one texture pointer
        gl.glGenTextures(1, textures, 0);
        // ...and bind it to our array
        gl.glBindTexture(GL10.GL_TEXTURE_2D, textures[0]);

        // create nearest filtered texture
        gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_MIN_FILTER, GL10.GL_NEAREST);
        gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_MAG_FILTER, GL10.GL_LINEAR);

        // Use Android GLUtils to specify a two-dimensional texture image from our bitmap
        GLUtils.texImage2D(GL10.GL_TEXTURE_2D, 0, tagImage, 0);

        // Clean up
        tagImage.recycle();
    }
    public void draw(GL10 gl) {
        // bind the previously generated texture
        gl.glBindTexture(GL10.GL_TEXTURE_2D, textures[0]);

        // Point to our buffers
        gl.glEnableClientState(GL10.GL_VERTEX_ARRAY);
        gl.glEnableClientState(GL10.GL_TEXTURE_COORD_ARRAY);

        // Set the face rotation
        gl.glFrontFace(GL10.GL_CW);

        // Point to our vertex buffer
        gl.glVertexPointer(3, GL10.GL_FLOAT, 0, vertexBuffer);
        gl.glTexCoordPointer(2, GL10.GL_FLOAT, 0, textureBuffer);

        // Draw the vertices as triangle strip
        gl.glDrawArrays(GL10.GL_TRIANGLE_STRIP, 0, vertices.length / 3);

        //Disable the client state before leaving
        gl.glDisableClientState(GL10.GL_VERTEX_ARRAY);
        gl.glDisableClientState(GL10.GL_TEXTURE_COORD_ARRAY);

    }

}

Answer 1

在这种情况下，我认为创建一个具有三个属性的类标记器（例如）更容易。例如：

class Marker {

int var1;
String var2;
BitmapData var3; }

这样，您就可以存储标记数组列表（ArrayList），并且可以访问您需要的所有信息。

Answer 2

速记：

List<MarkerCustom> markerList = Arrays.asList(
    new MarkerCustom(1, "hello", bitMapData1),
    new MarkerCustom(66, "johnHandy", bitMapData2))
};

Answer 3

试试这个。

List<MarkerCustom> myList=new ArrayList<MarkerCustom>();
MarkerCustom entry1=new MarkerCustom(myInt, myString, myBitmap);
MarkerCustom entry2=new MarkerCustom(myInt, myString, myBitmap);

myList.add(entry1);
myList.add(entry2);