問(wèn)題描述

我想在地圖視圖上畫一個(gè)圓圈.我希望用戶輸入半徑，對(duì)于該半徑，我必須在地圖上顯示圓圈.之后，我必須在該圓圈的某些位置顯示標(biāo)記.

I want to draw a circle on map view. I want the user to input the radius and for that radius I have to show circle on map. After that I have to display markers on some locations on that circle.

我知道如何在地圖視圖上顯示標(biāo)記.

I know how to display markers on on map view.

如何在地圖視圖上繪制圓圈并在該圓圈邊界上顯示標(biāo)記.

How can I draw circle on map view and to show markers on that circle boundary.

推薦答案

在ItemizedOverlay的實(shí)現(xiàn)中，做類似onDraw中的drawCircle方法方法

In the implementation of the ItemizedOverlay, do something like the method drawCircle from the onDraw method

protected void drawCircle(Canvas canvas, Point curScreenCoords) {
    curScreenCoords = toScreenPoint(curScreenCoords);
    int CIRCLE_RADIUS = 50;
    // Draw inner info window
    canvas.drawCircle((float) curScreenCoords.x, (float) curScreenCoords.y, CIRCLE_RADIUS, getInnerPaint());
    // if needed, draw a border for info window
    canvas.drawCircle(curScreenCoords.x, curScreenCoordsy, CIRCLE_RADIUS, getBorderPaint());
}

private Paint innerPaint, borderPaint;

public Paint getInnerPaint() {
    if (innerPaint == null) {
        innerPaint = new Paint();
        innerPaint.setARGB(225, 68, 89, 82); // gray
        innerPaint.setAntiAlias(true);
    }
    return innerPaint;
}

public Paint getBorderPaint() {
    if (borderPaint == null) {
        borderPaint = new Paint();
        borderPaint.setARGB(255, 68, 89, 82);
        borderPaint.setAntiAlias(true);
        borderPaint.setStyle(Style.STROKE);
        borderPaint.setStrokeWidth(2);
    }
    return borderPaint;
}

@Override
protected void onDraw(Canvas canvas) {
    Point p = new Point();
    for(OverlayItem item : items) {
        drawCircle(canvas, getProjection().toPixels(item.getPoint(), p));
    }
}

這篇關(guān)于在Android的地圖視圖上繪制一定半徑的圓的文章就介紹到這了，希望我們推薦的答案對(duì)大家有所幫助，也希望大家多多支持html5模板網(wǎng)！