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

我认为你可以使用Drawable。setColorFilter(0xffff0000,模式。用)。这将把白色像素设置为红色,但我不认为它会影响透明像素。

看到可拉的# setColorFilter

其他回答

view.getDrawable().mutate().setColorFilter(0xff777777, PorterDuff.Mode.MULTIPLY); 

谢谢@sabadow

这适用于所有有背景的东西:

Textview,按钮……

TextView text = (TextView) View.findViewById(R.id.MyText);
text.setBackgroundResource(Icon);    
text.getBackground().setColorFilter(getResources().getColor(Color), PorterDuff.Mode.SRC_ATOP);

如果你在ImageView中有可绘制的集合,你可以用一行代码完成:

yourImageView.setColorFilter(context.getResources().getColor(R.color.YOUR_COLOR_HERE);

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:

会帮助那些想要完全改变Drawable颜色的人吗

<ImageView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:background="@drawable/ic_memory"
    android:backgroundTint="@color/lime" />