canvas onDraw 不显示任何内容
the canvas onDraw does not show enything
我想要一个 canvas 来编辑 photos.i 从图库中获取照片并将其发送到我的自定义 View.but 我不知道如何在 canvas:
这是我的代码:
public class CanvasView extends View {
ImageView img;
Bitmap canvasBitmap;
Canvas drawCanvas;
public CanvasView(Context context) {
super(context);
}
public void setCanvasPath(String bitmap_path) {
BitmapFactory.Options decode_options = new BitmapFactory.Options();
decode_options.inMutable = true;
canvasBitmap = BitmapFactory.decodeFile(bitmap_path,decode_options);
drawCanvas = new Canvas(canvasBitmap);
drawCanvas.drawBitmap(canvasBitmap, 0, 0, null);
invalidate();
}
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
}
}
这是 xml 文件:
<!--?xml version="1.0" encoding="utf-8"?-->
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="fill_parent"
android:layout_height="fill_parent">
</LinearLayout>
你画错位图了canvas
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
if (canvasBitmap != null) {
canvas.drawBitmap(canvasBitmap, 0, 0, null);
}
}
我想要一个 canvas 来编辑 photos.i 从图库中获取照片并将其发送到我的自定义 View.but 我不知道如何在 canvas: 这是我的代码:
public class CanvasView extends View {
ImageView img;
Bitmap canvasBitmap;
Canvas drawCanvas;
public CanvasView(Context context) {
super(context);
}
public void setCanvasPath(String bitmap_path) {
BitmapFactory.Options decode_options = new BitmapFactory.Options();
decode_options.inMutable = true;
canvasBitmap = BitmapFactory.decodeFile(bitmap_path,decode_options);
drawCanvas = new Canvas(canvasBitmap);
drawCanvas.drawBitmap(canvasBitmap, 0, 0, null);
invalidate();
}
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
}
}
这是 xml 文件:
<!--?xml version="1.0" encoding="utf-8"?-->
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="fill_parent"
android:layout_height="fill_parent">
</LinearLayout>
你画错位图了canvas
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
if (canvasBitmap != null) {
canvas.drawBitmap(canvasBitmap, 0, 0, null);
}
}