android achartengine：尝试将图形导出为图像引发异常

在Android应用程序中,正尝试通过此代码将图形(我使用achartengine绘制)导出为Bitmap对象

public static Bitmap loadBitmapFromView(Context context, View view) {

    Bitmap bitmap;

    BitmapFactory.Options options = new BitmapFactory.Options();
    options.inPurgeable = true;
    options.inInputShareable = true;

    Bitmap dummy = null;
    try {
        dummy = BitmapFactory.decodeStream(context.getAssets().open("icon_add.png"), new Rect(-1,-1,-1,-1), options);
    } catch (IOException e) {
        e.printStackTrace();
    }
     bitmap = Bitmap.createBitmap(view.getLayoutParams().width,
        view.getLayoutParams().height, Bitmap.Config.ARGB_4444);
    Canvas c = new Canvas(bitmap);
    view.layout(0, 0, view.getLayoutParams().width, view.getLayoutParams().height);
    view.draw(c);
    c = null;

    return bitmap;
}

并将此方法称为：

loadBitmapFromView(getApplicationContext(), this.graphView);

其中graphView是GraphicalView类型的对象

但这引发了异常

java.lang.IllegalArgumentException: width and height must be > 0

在这条线

bitmap = Bitmap.createBitmap(view.getLayoutParams().width,
        view.getLayoutParams().height, Bitmap.Config.ARGB_4444);

有人可以帮忙吗？

解决方法:

每http://developer.android.com/reference/android/view/View.html#getLayoutParams()该方法返回

… layout parameters. These supply parameters to the parent of this view
specifying how it should be arranged.

即这些是布局计算的输入：

LayoutParams … describes how big the view wants to be for both width and height. For each
dimension, it can specify one of an exact number, MATCH_PARENT, WRAP_CONTENT

您需要实际的View大小,即布局计算的结果.

如果此View已经布置在屏幕上,则view.getWidth()和view.getHeight()应该返回其实际大小.在这种情况下,调用view.layout(…)可能会使显示的View处于您应该还原的怪异状态,并且再次要传递实际的尺寸信息,而不是布局参数.

如果此视图不在屏幕上,则应该在view.layout(…)之前调用view.measure(widthMeasureSpec,heightMeasureSpec).请务必阅读View文档.

标签：achartengine,android
来源： https://codeday.me/bug/20191013/1905361.html