創建一個空的位圖和繪製雖然Android中的畫布

Question

我想創建一個空位圖並將畫布設置爲該位圖，然後在位圖上繪製任何形狀。

Answer 1

這可能是更簡單的比你想：

int w = WIDTH_PX, h = HEIGHT_PX; 

Bitmap.Config conf = Bitmap.Config.ARGB_8888; // see other conf types 
Bitmap bmp = Bitmap.createBitmap(w, h, conf); // this creates a MUTABLE bitmap 
Canvas canvas = new Canvas(bmp); 

// ready to draw on that bitmap through that canvas 

這裏有一系列的教程，我的話題發現：Drawing with Canvas Series

Answer 2

不要使用Bitmap.Config.ARGB_8888

改爲使用 int w = WIDTH_PX，h = HEIGHT_PX;

Bitmap.Config conf = Bitmap.Config.ARGB_4444; // see other conf types 
Bitmap bmp = Bitmap.createBitmap(w, h, conf); // this creates a MUTABLE bitmap 
Canvas canvas = new Canvas(bmp); 

// ready to draw on that bitmap through that canvas 

當處理更多位圖或大型位圖時，ARGB_8888會將您置於OutOfMemory問題中。 或更好的是，儘量避免使用ARGB選項本身。