Question

我差不多完成了我在Eclipse中制作的应用程序。现在可以在操作栏中选择笔划宽度，颜色和清除屏幕。我遇到的问题是每当我点击操作栏时画布重置并且我丢失了我的画，当我选择不同的颜色或笔画大小时也会出现这种情况。当我启动应用程序时，我必须先单击操作栏才能绘制。这就是我遇到的问题。

另外，当我选择不同的笔划大小时，黑色笔触大小会正确改变，但是当我改变颜色后，笔划大小会调整为默认值。

以下是我的代码。我希望有人能够帮助我。谢谢！

SingleTouchActivity.java

public class SingleTouchActivity extends Activity {

    @Override

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

      }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {

        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
         SingleTouchEventView stev = new SingleTouchEventView(this, null);
            setContentView(stev);
            // Handle action bar item clicks here. The action bar will
            // automatically handle clicks on the Home/Up button, so long
            // as you specify a parent activity in AndroidManifest.xml.

            int id = item.getItemId();

            if (id == R.id.ResetAction) {
                invalidate();
                    return true;
            }if (id == R.id.LijnDun) {
                stev.setStrokeWidth(4);
                    return true;
            }if (id == R.id.LijnDik) {
                stev.setStrokeWidth(5);
                    return true;
            }
            if (id == R.id.LijnGroen) {
                stev.setColor(3);
                    return true;
            }
            if (id == R.id.LijnBlauw) {
                    stev.setColor(2);
                    return true;
            }
            if (id == R.id.LijnRood) {
                       stev.setColor(1);

                       return true;
            }

            return super.onOptionsItemSelected(item);
    }

    private void invalidate() {
        // TODO Auto-generated method stub

    }

    /**
     * A placeholder fragment containing a simple view.
     */
    public static class PlaceholderFragment extends Fragment {

        public PlaceholderFragment() {
        }

        @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container,
                Bundle savedInstanceState) {
            View rootView = inflater.inflate(R.layout.main_fragment, container,
                    false);
            return rootView;
        }
    }

}

SingleTouchEventView.Java

public class SingleTouchEventView extends View {
  private Paint paint = new Paint();
  private Path path = new Path();

  public SingleTouchEventView(Context context, AttributeSet attrs) {
    super(context, attrs);

    paint.setAntiAlias(true);
    paint.setStrokeWidth(5f);
    paint.setColor(Color.BLACK);
    paint.setStyle(Paint.Style.STROKE);
    paint.setStrokeJoin(Paint.Join.ROUND);

  }

  @Override
  protected void onDraw(Canvas canvas) {
    canvas.drawPath(path, paint);
  }

  @Override
  public boolean onTouchEvent(MotionEvent event) {
    float eventX = event.getX();
    float eventY = event.getY();

    switch (event.getAction()) {
    case MotionEvent.ACTION_DOWN:
      path.moveTo(eventX, eventY);
      return true;
    case MotionEvent.ACTION_MOVE:
      path.lineTo(eventX, eventY);
      break;
    case MotionEvent.ACTION_UP:
      // nothing to do
      break;
    default:
      return false;
    }

    // Schedules a repaint.
    invalidate();
    return true;
  }

  // KLEUR  switch statement
  void setColor(int i){

      switch (i){
         case 1:

             paint.setColor(Color.RED);

         break;

         case 2:

             paint.setColor(Color.BLUE);

         break;

         case 3:

             paint.setColor(Color.GREEN);

         break;

         default:

             paint.setColor(Color.BLACK);

         break;  

      }

    }
  // LIJN DIKTE  switch statement
  void setStrokeWidth(int k){

      switch (k){
         case 5:

             paint.setStrokeWidth(12f);

         break;

         case 4:

             paint.setStrokeWidth(5f);

         break;

        default:

             paint.setStrokeWidth(5f);

         break;  

      }

    }
}

Answer 1

在onOptionsItemSelected中，您每次都要创建一个新的View实例。这会将所有值重置为默认值，然后执行选项按钮操作。您必须对视图的现有实例执行更改。使你的视图单身。

选择其他颜色时，绘制笔触宽度将更改为默认值

1 个答案: