問題描述

我想在地圖視圖上畫一個圓圈.我希望用戶輸入半徑，對于該半徑，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的實現中，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大家有所幫助，也希望大家多多支持html5模板網！