Android 中在 ImageView 上绘制图层
谁能指导我如何在 ImageView 组件上显示的图像上放置不同的绘图层。 基本上我想在我的绘图应用程序中实现撤消和重做功能。
目前我可以在图像上放置文本或绘图，但无法实现撤消/重做功能。我想知道这可以通过维护一些分层的东西来实现。
请帮帮我。
这是我当前的绘图代码..
try {
image.buildDrawingCache();
Bitmap bitmap = image.getDrawingCache();
try
{
bitmap = getResizedBitmap(bitmap, image.getHeight(),
image.getWidth());
} catch (OutOfMemoryError e) {
Toast.makeText(getApplicationContext(), e.getMessage(), 1)
.show();
}
TextPaint tp = new TextPaint();
tp.setColor(Color.GREEN);
tp.setAntiAlias(true);
tp.setTextSize(30);
Canvas canvas = new Canvas(bitmap);
canvas.drawText(input.getText().toString(), xPos, yPos, tp);
image.setImageBitmap(bitmap);
input.setText("");
input.setVisibility(View.INVISIBLE);
} catch (Exception e) {
Toast.makeText(getApplicationContext(), e.getMessage(), 1).show();
}
提前感谢...!!!
Can anyone guide me how can I put different drawing layers on an Image which is shown over ImageView component.
Basically I want to implement Undo and Redo Functionality in my drawing application.
Currently I can put text or Drawing over image but can't achieve Undo/Redo functionality. I wonder this can be possible by maintaining some layering stuff.
Plz help me out.
this is my current drawing code..
try {
image.buildDrawingCache();
Bitmap bitmap = image.getDrawingCache();
try
{
bitmap = getResizedBitmap(bitmap, image.getHeight(),
image.getWidth());
} catch (OutOfMemoryError e) {
Toast.makeText(getApplicationContext(), e.getMessage(), 1)
.show();
}
TextPaint tp = new TextPaint();
tp.setColor(Color.GREEN);
tp.setAntiAlias(true);
tp.setTextSize(30);
Canvas canvas = new Canvas(bitmap);
canvas.drawText(input.getText().toString(), xPos, yPos, tp);
image.setImageBitmap(bitmap);
input.setText("");
input.setVisibility(View.INVISIBLE);
} catch (Exception e) {
Toast.makeText(getApplicationContext(), e.getMessage(), 1).show();
}
thanks in advance...!!!
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用另一种方式完成。
创建原始位图并将其保存在某个位图变量中。现在，在每个 onDraw 调用中都会使用原始位图启动一个位图并将其传递到画布。然后做你想做的事..
Done it in another way.
Create orignal bitmap and save it in some bitmap variable. Now on every onDraw call initiate a bitmap with orignal one and pass it to canvas. Then do what you want to do..
尝试 Android 中的 LayerDrawable
http://developer.android.com/guide /topics/resources/drawable-resource.html#LayerList
Try LayerDrawable from Android
http://developer.android.com/guide/topics/resources/drawable-resource.html#LayerList