以模擬器屏幕的寬和高作為畫板

• 代碼文件

public class DrawDemoActivity extends Activity {
    private ImageView iv;
    Display current = null;
    Canvas cv = null;
    Paint paint = null;
    Bitmap bitmap = null;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        iv=(ImageView) findViewById(R.id.iv);
        current = getWindowManager().getDefaultDisplay();
        //以模擬器屏幕的寬高作為畫板
        bitmap = Bitmap.createBitmap(current.getWidth(), current.getHeight(),
                Bitmap.Config.ARGB_8888);//可變視圖創建完成
        //繪制畫布
        cv=new Canvas(bitmap);
        //繪制畫筆
        paint=new Paint();
        //設置顏色
        int color=Color.argb(128, 50, 98, 60);
        paint.setColor(color);
        //設置樣式
        paint.setStrokeWidth(12.5f);//筆的寬度
        paint.setStyle(Paint.Style.STROKE);//填充或者不填充
        //繪制圖形
        cv.drawPoint(50, 50, paint);//點
        cv.drawLine(50, 50, 160, 200, paint);//直線
        cv.drawRect(80, 80, 220, 220, paint);//矩形
        
        //繪制圓
        RectF rf=new RectF(60, 60, 100, 120);
        cv.drawOval(rf, paint);
        
        //路徑 moveto  lineto
        Path p=new Path();
        //繪制封閉圖形
        p.moveTo(60, 60);
        p.lineTo(80,90);
        p.lineTo(100, 120);
        p.lineTo(150, 180);
        p.lineTo(200, 220);
        //繪制路徑
        cv.drawPath(p, paint);
        
        //繪制文本
        paint.setColor(Color.BLUE);
        paint.setStrokeWidth(2.0f);//畫筆寬度
        paint.setTextSize(100);
        cv.drawText("你好，",20, 80, paint);
        //將繪制好的圖形在顯示器上顯示出來
        iv.setImageBitmap(bitmap);
    }
}

• 布局文件

<ImageView 
        android:id="@+id/iv"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        />