android canvas drawrect画图 为什么在android中调用canvas.drawRect时只绘制一个矩形？

我正在尝试使用foreach循环为ArrayList中的每个字符串绘制一个矩形，但它似乎只绘制了最后一个矩形。

我看过类似的问题，但他们遇到的问题包括矩形底部高于顶部并调用drawPaint - 但我没有这些问题。

MainActivity.java

public class MainActivity extends AppCompatActivity {

ArrayList ideas = new ArrayList<>();

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

// set the icon

ActionBar actionBar = getSupportActionBar();

assert actionBar != null;

actionBar.setDisplayShowHomeEnabled(true);

actionBar.setIcon(R.drawable.actionbarfull);

//Use API in future to GET all ideas

ideas.add("Idea 1");

ideas.add("Idea 2");

ideas.add("Idea 3");

setContentView(new IdeaRectangle(this, ideas));

}

}

IdeaRectangle.java

public class IdeaRectangle extends View {

Rect rectangle = new Rect();

Paint mBlue = new Paint();

Paint textPaint = new Paint();

ArrayList ideasToDraw = new ArrayList<>();

int gap = 50;

int sidegap = 30;

int right = 0;

int height = 250;

int top = 0;

int bottom = 0;

int counter = 0;

public IdeaRectangle(Context context) {

super(context);

}

public IdeaRectangle(Context context, ArrayList ideas) {

super(context);

ideasToDraw = ideas;

}

@Override

protected void onDraw(Canvas canvas) {

super.onDraw(canvas);

// Setting colour of rectangle and text

mBlue.setARGB(255, 0, 183, 255);

textPaint.setTextSize(50);

textPaint.setARGB(255, 0, 0, 0);

ArrayList rectangles = drawIdea(canvas, ideasToDraw);

for (Rect rectangle : rectangles) {

// Draw rectangle

canvas.drawRect(rectangle, mBlue);

canvas.drawText("This is an idea. There were " + rectangles.size() + " rectangles.", rectangle.left, rectangle.centerY(), textPaint);

}

}

private ArrayList drawIdea(Canvas canvas, ArrayList ideas) {

ArrayList rectangles = new ArrayList<>();

right = canvas.getWidth() - sidegap;

for (String idea : ideas) {

// Setting location of rectangle

top = gap + (counter * (gap + height));

bottom = top + height;

counter++;

System.out.println(sidegap + "," + top + "," + right + "," + bottom);

rectangle.set(sidegap, top, right, bottom);

rectangles.add(rectangle);

}

return rectangles;

}

打印出矩形尺寸的控制台日志打印出来：

04-23 12:47:44.920 11005-11005/? I/System.out: 30,50,1050,300

04-23 12:47:44.920 11005-11005/? I/System.out: 30,350,1050,600

04-23 12:47:44.920 11005-11005/? I/System.out: 30,650,1050,900