TextView文字颜色渐变

TextView文字颜色渐变

import android.graphics.LinearGradient
import android.graphics.Shader
import android.widget.TextView

/**
 * 左到右渐变
 */
fun TextView.setHorizontalGradientTextColor(startColor: Int, endColor: Int) {
    val x1 = this.paint.measureText(this.text.toString())//测量文本 宽度
    val shader = LinearGradient(0f, 0f, x1, 0f, startColor, endColor, Shader.TileMode.CLAMP)
    this.paint.shader = shader
    this.invalidate()
}

/**
 * 上到下渐变
 */
fun TextView.setVerticalGradientTextColor(startColor: Int, endColor: Int) {
    val y1 = this.paint.textSize//测量文本 高度
    val shader = LinearGradient(0f, 0f, 0f, y1, startColor, endColor, Shader.TileMode.CLAMP)
    this.paint.shader = shader
    this.invalidate()
}

使用方式，调用扩展方法即可

textView.setHorizontalGradientTextColor(Color.RED, Color.GREEN)