我试图在画布上绘制4个矩形,以便画布分成4个相等的矩形。使用我现在的代码,只绘制代码中的最后一个矩形。
这是我的活动中的代码:
protected void onCreate(Bundle savedInstanceState) {
...
setContentView(new MyView(this));
}
public class MyView extends View {
public MyView(Context context) {
super(context);
// TODO Auto-generated constructor stub
setFocusableInTouchMode(true);
}
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
int x = getWidth();
int y = getHeight();
Paint paintTopLeft = new Paint();
paintTopLeft.setStyle(Paint.Style.FILL);
paintTopLeft.setColor(Color.WHITE);
canvas.drawPaint(paintTopLeft);
// Use Color.parseColor to define HTML colors
paintTopLeft.setColor(Color.parseColor("#F44336"));
canvas.drawRect(0,0,x / 2,y / 2,paintTopLeft);
Paint paintTopRight = new Paint();
paintTopRight.setStyle(Paint.Style.FILL);
paintTopRight.setColor(Color.WHITE);
canvas.drawPaint(paintTopRight);
// Use Color.parseColor to define HTML colors
paintTopRight.setColor(Color.parseColor("#2196F3"));
canvas.drawRect(x / 2, 0, x, y / 2, paintTopRight);
}
}
我做错了什么?
答案 0 :(得分:2)
实际上我只看到两个用你的代码绘制的矩形。但无论如何,问题是你正在调用canvas.drawPaint,用这种颜色清除/填充整个画布。因此,您正在删除在绘制最后一个之前已经绘制的所有矩形。
此代码应该有效:
protected void onCreate(Bundle savedInstanceState) {
...
setContentView(new MyView(this));
}
public class MyView extends View {
public MyView(Context context) {
super(context);
// TODO Auto-generated constructor stub
setFocusableInTouchMode(true);
}
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
int x = getWidth();
int y = getHeight();
Paint paintTopLeft = new Paint();
paintTopLeft.setStyle(Paint.Style.FILL);
paintTopLeft.setColor(Color.WHITE);
//canvas.drawPaint(paintTopLeft); // don't do that
// Use Color.parseColor to define HTML colors
paintTopLeft.setColor(Color.parseColor("#F44336"));
canvas.drawRect(0,0,x / 2,y / 2,paintTopLeft);
Paint paintTopRight = new Paint();
paintTopRight.setStyle(Paint.Style.FILL);
paintTopRight.setColor(Color.WHITE);
// canvas.drawPaint(paintTopRight); // don't do that
// Use Color.parseColor to define HTML colors
paintTopRight.setColor(Color.parseColor("#2196F3"));
canvas.drawRect(x / 2, 0, x, y / 2, paintTopRight);
}
}