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我无法访问颜色。亮度静态方法

android

George Udosen · 技术社区 · 8 年前

我正试图用这种方法改变颜色亮度 Color.luminance 在我的android应用程序中,但我不断收到错误:

java.lang.NoSuchMethodError:类Landroid/graphics/Color中没有静态方法亮度(I)F;或者它的超级类(声明“android.graphics.Color”出现在/system/framework/framework.jar中)

在查看这个静态方法的声明文档时,我看到:

/**
     * Returns the relative luminance of a color.
     * <p>
     * Assumes sRGB encoding. Based on the formula for relative luminance
     * defined in WCAG 2.0, W3C Recommendation 11 December 2008.
     *
     * @return a value between 0 (darkest black) and 1 (lightest white)
     */
    public static float luminance(@ColorInt int color) {
        ColorSpace.Rgb cs = (ColorSpace.Rgb) ColorSpace.get(ColorSpace.Named.SRGB);
        DoubleUnaryOperator eotf = cs.getEotf();

        double r = eotf.applyAsDouble(red(color) / 255.0);
        double g = eotf.applyAsDouble(green(color) / 255.0);
        double b = eotf.applyAsDouble(blue(color) / 255.0);

        return (float) ((0.2126 * r) + (0.7152 * g) + (0.0722 * b));
    }

很明显它就在那里,但在运行时它会出错,我不明白是什么错了,我的代码:

private float luminance = Color.luminance(color);

梯度依赖:

apply plugin: 'com.android.application'

android {
    publishNonDefault true

    compileSdkVersion 27
    buildToolsVersion "27.0.3"
    defaultConfig {
        applicationId "com.george.value"
        minSdkVersion 22
        targetSdkVersion 27
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    implementation fileTree(include: ['*.jar'], dir: 'libs')
    implementation 'com.android.support:appcompat-v7:27.0.2'
    implementation 'com.android.support:design:27.0.2'
    implementation 'com.android.support:preference-v7:27.0.2'
    implementation 'com.android.support.constraint:constraint-layout:1.0.2'
    implementation 'com.android.support:cardview-v7:27.0.2'
    implementation 'com.android.support:recyclerview-v7:27.0.2'
    testImplementation 'junit:junit:4.12'
}