CODEWITHSUNDEEP
androidandroid-canvasandroid-viewdrawrectrectangles
stedy
stedy

Reputation: 263

Drawing rectangles by treating canvas as a View

Is there an easy way to draw rectangles on a canvas and display it in an activity like a TextView?

I tried to draw my rectangle like this:

Paint paint = new Paint();
paint.setStyle(Paint.Style.FILL);
paint.setColor(Color.MAGENTA); 
Bitmap b = Bitmap.createBitmap(100, 100, Bitmap.Config.ARGB_8888);
Canvas c = new Canvas(b);

Rect locationrect = new Rect(10, 10, 200, 100);
c.drawRect(locationrect, paint);

View locationpic = (View)findViewById(R.id.locationview);
locationpic.draw(c);

in my xml:

<View
    android:id="@+id/locationview"
    android:layout_width="520dp"
    android:layout_height="489dp"
    android:layout_marginLeft="40dp"
    android:layout_marginTop="220dp" />

This is apparently not working (it doesn't crash but rectangle is not displayed).. any help would be appreciated! Thanks!

Upvotes: 1

Views: 710

Answers (1)

Lavekush
Lavekush

Reputation: 6166

Create a Java file and write this:

package com.samplecanvas;

import java.util.ArrayList;

import android.app.Activity; import android.content.Context; import android.graphics.Bitmap; import android.graphics.Canvas; import android.graphics.Color; import android.graphics.Paint; import android.graphics.Path; import android.graphics.Rect; import android.graphics.RectF; import android.os.Bundle; import android.view.MotionEvent; import android.view.SurfaceHolder; import android.view.SurfaceView; import android.view.View; import android.view.View.OnTouchListener; import android.view.ViewGroup.LayoutParams; import android.view.Window; import android.view.WindowManager; import android.widget.FrameLayout;

import android.content.Context; import android.graphics.Canvas; import android.graphics.Color; import android.graphics.Paint; import android.view.View;

      public class SampleCanvasActivity extends View {
         vPaint paint = new Paint();

          public SampleCanvasActivity(Context context) {
              super(context);
           }

@Override
public void onDraw(Canvas canvas) {
    paint.setColor(Color.BLACK);
    paint.setStrokeWidth(3);
    canvas.drawRect(130, 130, 180, 180, paint);
    paint.setStrokeWidth(0);
    paint.setColor(Color.CYAN);
    canvas.drawRect(133, 160, 177, 177, paint );
    paint.setColor(Color.YELLOW);
    canvas.drawRect(133, 133, 177, 160, paint );

}

}

Use this file in ur xml

Like this.

  <com.samplecanvas.SampleCanvasActivity
android:id="@+id/widthView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="30dp"
android:layout_marginTop="150dp"
 />

Upvotes: 1

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