Question

我花了大约3个小时试图解决这个问题，看起来很简单，但我似乎无法解决这个问题！请有人帮帮我！我只想让它显示可绘制资源文件夹中的图像。它说“无法从Bitmap转换为Drawable”。

package com.CS3040.Places;

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Point;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import com.CS3040.*;
import com.CS3040.Coursework.R;

import com.google.android.maps.GeoPoint;
import com.google.android.maps.MapView;
import com.google.android.maps.OverlayItem;

public class PlaceOverlayItem extends OverlayItem {
    private final GeoPoint point;
    private final Place place;
    private final Drawable marker;
    //private final Context context;

    public PlaceOverlayItem(Context context, Place p, String type) {
        super(p.getGeoPoint(), p.getName(), p.getFormatted_address());

        if(type.equals("restaurant"))
        { 
            //this.marker =
            Bitmap bmp = BitmapFactory.decodeResource(context.getResources(), R.drawable.restaurant);
            this.marker = bmp;

        } 

        //super.setMarker(this.marker);
        this.point = p.getGeoPoint();
        this.place = p;
    }

    /**
     * @return the point
     */
    public GeoPoint getPoint() {
        return point;
    }

    /**
     * @return the place
     */
    public Place getPlace() {
        return place;
    }

    }

Answer 1

嗯，这是正确的 - Bitmap 不扩展Drawable。我没有做任何Android开发，但听起来你想要一个BitmapDrawable：

Resources resources = context.getResources();
Bitmap bmp = BitmapFactory.decodeResource(resources, R.drawable.restaurant);
this.marker = new BitmapDrawable(resources, bmp);

Answer 2

您需要将您的资源作为Drawable：

if(type.equals("restaurant"))
{ 
    this.marker = context.getResources().getDrawable(R.drawable.restaurant);
} else {
    // marker would get no value without that else case - not allowed if you declare it final
    this.marker = null;
}

Answer 3

改变这个：

Bitmap bmp = BitmapFactory.decodeResource(context.getResources(), R.drawable.restaurant);
this.marker = bmp;

到此：

Drawable d = context.getResources().getDrawable(R.drawable.restaurant);
d.setBounds(0, 0, d.getIntrinsicWidth(), d.getIntrinsicHeight());
this.marker = d;

无法将Bitmap转换为Drawable，为什么我会收到此错误？

3 个答案: