Java 如何将 onclick 侦听器设置为画布？
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How to set an onclick listener to a canvas?
提问by
I have some rectangles drawn on Canvas. And now I need for each rectangle an onclickListener.
But because I'm very new to android and specially Canvas, I need some help.
Anyway is it possible to add a listener?
我在 上绘制了一些矩形Canvas。现在我需要为每个矩形一个onclickListener. 但是因为我对 android 很陌生，特别是Canvas，我需要一些帮助。无论如何可以添加一个监听器吗？
It looks like this:
它看起来像这样：
And this is my code for it:
这是我的代码：
RelativeLayout ll = (RelativeLayout) findViewById(R.id.rect);
Paint paint = new Paint();
Paint paintForSize = new Paint();
paintForSize.setColor(Color.parseColor("#FFFFFF"));
paintForSize.setTextSize(45);
Bitmap bg = Bitmap.createBitmap(480, 800, Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(bg);
int left = 0; // initial start position of rectangles (50 pixels from left)
int leftText =70;
int topText = 93;
int top = 50; // 50 pixels from the top
int width = 60;
int height = 60;
for(int x = 0; x < 4; x++) { // draw 4 rectangles
if(x == 0){
paint.setColor(Color.parseColor("#FF7979"));
canvas.drawText("Rec 1", leftText, topText, paintForSize);
}
if(x == 1){
paint.setColor(Color.parseColor("#FFD060"));
canvas.drawText("Rec 2", leftText, topText, paintForSize);
}
if(x == 2){
paint.setColor(Color.parseColor("#B6DB49"));
canvas.drawText("Rec 3", leftText, topText, paintForSize);
}
if(x == 3){
paint.setColor(Color.parseColor("#CB97E5"));
canvas.drawText("Rec 4", leftText, topText, paintForSize);
}
canvas.drawRect(left, top, left+width, top+height, paint);
top = (top + height + 10); // set new left co-ordinate + 10 pixel gap
topText = (topText + height + 10);
}
RelativeLayout.LayoutParams params = new RelativeLayout.LayoutParams(LayoutParams.WRAP_CONTENT,
LayoutParams.WRAP_CONTENT);
params.addRule(RelativeLayout.ALIGN_PARENT_LEFT);
ImageView iV = new ImageView(this);
iV.setImageBitmap(bg);
ll.addView(iV,params);
Can anybody guide me through this, how should I do it?
任何人都可以指导我完成这个，我该怎么做？
采纳答案by Husman
Might I suggest rethinking how this is going to work. If these rectangles are going to be buttons of some sort, perhaps your better off drawing buttons in your user interface, or using images instead of the rectangles. (Sorry didnt realise this is what you were going to do in your previous question)
我是否建议重新考虑这将如何运作。如果这些矩形将成为某种按钮，也许您最好在用户界面中绘制按钮，或者使用图像而不是矩形。（对不起，没有意识到这是你在上一个问题中要做的）
Have a look at: Difference between a clickable ImageView and ImageButton
看一看：Difference between a clickable ImageView and ImageButton
You can set an eventlistener on your imageview, as mentioned in another answer. See here: Image in Canvas with touch events
您可以在 imageview 上设置事件侦听器，如另一个答案中所述。请参阅此处：带有触摸事件的画布中的图像
回答by Naddy
Canvasis not a View. You cannot add listeners to them. You could create a custom View implementation. Whatever you do with the Canvas, implement that in onDraw(), which receives a Canvasas a parameter. Then add your view to a layout and give it whatever listeners you want. You may as well look into SurfaceViewfor drawing, which is a View.
Canvas不是View. 您不能向它们添加侦听器。您可以创建自定义视图实现。无论你用 做什么，在Canvas中实现它onDraw()，它接收 aCanvas作为参数。然后将您的视图添加到布局中，并为其提供您想要的任何侦听器。您不妨研究一下SurfaceView绘图，这是一个View.
Thismight help you.
这可能对你有帮助。
