java 使用可从资源绘制的位图初始化位图变量不起作用 - 使用 ANDROID
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Initializing Bitmap variable with bitmap drawable from resources is not working - using ANDROID
提问by a_schimpf
I use the following code to initialize my bitmap variable:
我使用以下代码来初始化我的位图变量：
Bitmap bitmap = ((BitmapDrawable)this.model.gameView.context.getResources().getDrawable(R.drawable.pic1)).getBitmap();
When I try to log the width of that bitmap, the log does not even output anything for that call.
当我尝试记录该位图的宽度时，日志甚至不为该调用输出任何内容。
I know it's making it to that line, because I traced the code.
我知道它正在到达那条线，因为我跟踪了代码。
Also, when I try to do canvas.draw for the bitmap, nothing is drawn on the screen.
此外，当我尝试为位图执行 canvas.draw 时，屏幕上没有绘制任何内容。
Everything I draw with rectangles works fine.
我用矩形绘制的所有东西都可以正常工作。
My picture resource is a PNG.
我的图片资源是 PNG。
Any help is appreciated!
任何帮助表示赞赏！
采纳答案by a_schimpf
Just figured it out. It had nothing to do with the method of bitmap loading I used. It was a logical error on my part. My code accidentally reached a case where my bitmap became null, and it tried to draw the null resource on the canvas.
刚刚想通了。它与我使用的位图加载方法无关。就我而言，这是一个逻辑错误。我的代码不小心遇到了位图变为空的情况，它试图在画布上绘制空资源。
回答by corecase
Try something like this for your bitmap class.
为您的位图类尝试类似的操作。
public class DrawBitmap extends View
{
Bitmap bitmap;
public DrawBitmap(Context content)
{
super(content);
bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.pic1);
}
@Override
protected void onDraw(Canvas canvas)
{
super.onDraw(canvas);
canvas.drawColor(Color.BLACK);//whatever color you want, make sure it's not the same as your image
canvas.drawBitmap(bitmap, (canvas.getWidth()), 0, null);
}
}
Main Class
主班
public class Main extends Activity
{
DrawBitmap myView;
@Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
myView = new DrawBitmap(this);
setContentView(myView);
}
}
回答by Serdar Samanc?o?lu
Try using BitmapFactory.decodeResource Have a look at the answer in this topic: How to convert a Drawable to a Bitmap?
尝试使用 BitmapFactory.decodeResource 看看本主题中的答案： 如何将 Drawable 转换为位图？
