Question

这是我写的代码：---

public class board extends Activity 
 {  
     Canvas canvas;Bitmap bitmap;

public void onCreate(Bundle savedInstanceState) 
{
    super.onCreate(savedInstanceState);


    DisplayMetrics metrics = getResources().getDisplayMetrics();
    int width = metrics.widthPixels;
    int height = metrics.heightPixels;
    Log.d("board", "height is" + height + "width"+ width ); 


     bitmap = Bitmap.createBitmap(width, height, Config.RGB_565);

    Paint blue = new Paint();
    Paint red = new Paint();
    Paint green = new Paint();
    Paint yellow = new Paint();

    blue.setColor(Color.BLUE);
    blue.setStrokeWidth(5);

    red.setColor(Color.RED);
    red.setStrokeWidth(5);
    green.setColor(Color.GREEN);
    green.setStrokeWidth(5);
    yellow.setColor(Color.YELLOW);
    yellow.setStrokeWidth(5);



     canvas = new Canvas(bitmap);

      canvas.drawColor(Color.BLACK);

      red.setStyle(Paint.Style.FILL);

        Path path = new Path();
        path.setFillType(FillType.EVEN_ODD);
        path.moveTo(width/5, height/3);
        path.lineTo((4*width)/5, (height)/3);
        path.moveTo((4*width)/5, (height)/3);
        path.lineTo(width/2, (17*height)/30);
        path.moveTo(width/2, (17*height)/30);
        path.lineTo(width/5, height/3);
        path.moveTo(width/5, height/3);
        path.close();
        canvas.drawPath(path, red);

    ImageView imageView = new ImageView(this);

    imageView.setImageBitmap(bitmap);

    RelativeLayout layout = new RelativeLayout(this);
    RelativeLayout.LayoutParams params = new 
        RelativeLayout.LayoutParams(LayoutParams.WRAP_CONTENT,
       LayoutParams.WRAP_CONTENT);
    params.addRule(RelativeLayout.CENTER_IN_PARENT);
    layout.addView(imageView, params);
    layout.setBackgroundColor(Color.BLACK);

    setContentView(layout);



}

所需产出： - 黑色背景上的红色填充三角形。

我得到的输出： - 只是一个黑色的背景。

导致错误的代码有什么问题。

Answer 1

您只需要第一个 path.moveTo（）。删除所有其他出现的path.moveTo（）：

Path path = new Path();
path.setFillType(FillType.EVEN_ODD);
path.moveTo(width/5, height/3);          //<----- keep only this call to moveTo()
path.lineTo((4*width)/5, (height)/3);
path.moveTo((4*width)/5, (height)/3);    //<----- remove this call
path.lineTo(width/2, (17*height)/30);
path.moveTo(width/2, (17*height)/30);    //<----- remove this call
path.lineTo(width/5, height/3);
path.moveTo(width/5, height/3);          //<----- remove this call
path.close();
canvas.drawPath(path, red);
//rest of the code

路径图没有显示

1 个答案: