我有一个LinearLayout
,并且我有一个自定义视图:
public class myView extends View
{
Rect rects = new Rect(30,30,80,80);
Canvas myCanvas;
@Override
public void onDraw(Canvas canvas)
{
myCanvas = canvas;
paint.setColor(Color.RED);
canvas.drawRect(rects, paint);
}
void changeColor()
{
paint.setColor(Color.BLUE);
myCanvas.drawRect(rects, paint);
myCanvas.invalidate();
}
}
在MainActivity中,我有以下内容:
LinearLayout lv = (LinearLayout) View.inflate(this, R.layout.activity_main, null);
drawView = new myView(this);
lv.addView(drawView);
setContentView(lv);
Button button3 = (Button) findViewById(R.id.button3);
button3.setOnClickListener(new View.OnClickListener()
{
@Override
public void onClick(View v) {
drawView.changeColor();
}
});
点击按钮后,我想通过调用changeColor函数来改变矩形的颜色。但是会创建一个新的矩形出现在其他位置!请问你能帮助我解决吗?