我在一个android应用程序上工作,我有一个可绘制的,我正在从源图像加载。在这个图像上,我想将所有的白色像素转换为不同的颜色,比如蓝色,然后缓存生成的Drawable对象,以便以后使用它。

例如,我有一个20x20的PNG文件,中间有一个白色的圆圈,圆圈之外的一切都是透明的。把白色圆圈变成蓝色并缓存结果的最好方法是什么?如果我想使用源图像来创建几个新的Drawables(比如蓝色、红色、绿色、橙色等),答案会改变吗?

我猜我想在某种程度上使用一个ColorMatrix,但我不确定如何。


当前回答

当你使用一个库来为你做这件事时,这是非常非常简单的。 试试这个库

你可以这样调用:

Icon.on(holderView).color(R.color.your_color).icon(R.mipmap.your_icon).put();

其他回答

它适用于一些简单的绘图。我用它在一个简单的纯色矩形圆角形状和需要改变的颜色与不同的布局。

试试这个

android:backgroundTint="#101010"

查看这个示例代码"ColorMatrixSample.java"

/*
 * Copyright (C) 2007 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.example.android.apis.graphics;

import com.example.android.apis.R;

import android.app.Activity;
import android.content.Context;
import android.graphics.*;
import android.os.Bundle;
import android.view.KeyEvent;
import android.view.View;

public class ColorMatrixSample extends GraphicsActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(new SampleView(this));
    }

    private static class SampleView extends View {
        private Paint mPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
        private ColorMatrix mCM = new ColorMatrix();
        private Bitmap mBitmap;
        private float mSaturation;
        private float mAngle;

        public SampleView(Context context) {
            super(context);

            mBitmap = BitmapFactory.decodeResource(context.getResources(),
                                                   R.drawable.balloons);
        }

        private static void setTranslate(ColorMatrix cm, float dr, float dg,
                                         float db, float da) {
            cm.set(new float[] {
                   2, 0, 0, 0, dr,
                   0, 2, 0, 0, dg,
                   0, 0, 2, 0, db,
                   0, 0, 0, 1, da });
        }

        private static void setContrast(ColorMatrix cm, float contrast) {
            float scale = contrast + 1.f;
               float translate = (-.5f * scale + .5f) * 255.f;
            cm.set(new float[] {
                   scale, 0, 0, 0, translate,
                   0, scale, 0, 0, translate,
                   0, 0, scale, 0, translate,
                   0, 0, 0, 1, 0 });
        }

        private static void setContrastTranslateOnly(ColorMatrix cm, float contrast) {
            float scale = contrast + 1.f;
               float translate = (-.5f * scale + .5f) * 255.f;
            cm.set(new float[] {
                   1, 0, 0, 0, translate,
                   0, 1, 0, 0, translate,
                   0, 0, 1, 0, translate,
                   0, 0, 0, 1, 0 });
        }

        private static void setContrastScaleOnly(ColorMatrix cm, float contrast) {
            float scale = contrast + 1.f;
               float translate = (-.5f * scale + .5f) * 255.f;
            cm.set(new float[] {
                   scale, 0, 0, 0, 0,
                   0, scale, 0, 0, 0,
                   0, 0, scale, 0, 0,
                   0, 0, 0, 1, 0 });
        }

        @Override protected void onDraw(Canvas canvas) {
            Paint paint = mPaint;
            float x = 20;
            float y = 20;

            canvas.drawColor(Color.WHITE);

            paint.setColorFilter(null);
            canvas.drawBitmap(mBitmap, x, y, paint);

            ColorMatrix cm = new ColorMatrix();

            mAngle += 2;
            if (mAngle > 180) {
                mAngle = 0;
            }

            //convert our animated angle [-180...180] to a contrast value of [-1..1]
            float contrast = mAngle / 180.f;

            setContrast(cm, contrast);
            paint.setColorFilter(new ColorMatrixColorFilter(cm));
            canvas.drawBitmap(mBitmap, x + mBitmap.getWidth() + 10, y, paint);

            setContrastScaleOnly(cm, contrast);
            paint.setColorFilter(new ColorMatrixColorFilter(cm));
            canvas.drawBitmap(mBitmap, x, y + mBitmap.getHeight() + 10, paint);

            setContrastTranslateOnly(cm, contrast);
            paint.setColorFilter(new ColorMatrixColorFilter(cm));
            canvas.drawBitmap(mBitmap, x, y + 2*(mBitmap.getHeight() + 10),
                              paint);

            invalidate();
        }
    }
}

有关的API可在此下载:

Koltin解决方案使用视图绑定:

binding.avatar.drawable.colorFilter = BlendModeColorFilterCompat.createBlendModeColorFilterCompat(R.color.white, BlendModeCompat.SRC_ATOP)

这使用了最新版本的核心androidx库。

试着android: backgroundTint = " @color / quantum_black_100”

如果你有一个纯色的可绘制对象,你想把它改成不同的纯色,你可以使用ColorMatrixColorFilter。透明度得以保留。

int iColor = Color.parseColor(color);

int red   = (iColor & 0xFF0000) / 0xFFFF;
int green = (iColor & 0xFF00) / 0xFF;
int blue  = iColor & 0xFF;

float[] matrix = { 0, 0, 0, 0, red,
                   0, 0, 0, 0, green,
                   0, 0, 0, 0, blue,
                   0, 0, 0, 1, 0 };

ColorFilter colorFilter = new ColorMatrixColorFilter(matrix);
drawable.setColorFilter(colorFilter);