How to draw a line in android

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野趣味
野趣味 2020-11-22 06:27

Can anybody tell how to draw a line in Android, perhaps with an example?

15条回答
  •  一个人的身影
    2020-11-22 07:03

    This one draws 2 lines which form a cross on the top left of the screen:

    DrawView.java

    import android.content.Context;
    import android.graphics.Canvas;
    import android.graphics.Color;
    import android.graphics.Paint;
    import android.view.View;
    
    public class DrawView extends View {
        Paint paint = new Paint();
    
        private void init() {
            paint.setColor(Color.BLACK);
        }
    
        public DrawView(Context context) {
            super(context);
            init();
        }
    
        public DrawView(Context context, AttributeSet attrs) {
            super(context, attrs);
            init();
        }
    
        public DrawView(Context context, AttributeSet attrs, int defStyle) {
            super(context, attrs, defStyle);
            init();
        }
    
        @Override
        public void onDraw(Canvas canvas) {
                canvas.drawLine(0, 0, 20, 20, paint);
                canvas.drawLine(20, 0, 0, 20, paint);
        }
    
    }
    

    The activity to start it:

    StartDraw.java

    import android.app.Activity;
    import android.graphics.Color;
    import android.os.Bundle;
    
    public class StartDraw extends Activity {
        DrawView drawView;
    
        @Override
        public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
    
            drawView = new DrawView(this);
            drawView.setBackgroundColor(Color.WHITE);
            setContentView(drawView);
    
        }
    }
    

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