帮我写一个Android自定义View进度条，进度条颜色是渐变色，宽高可以自行设置

好的，以下是一个简单的 Android 自定义 View 进度条的代码，进度条颜色为渐变色，宽高可以自行设置：

public class GradientProgressBar extends View {
    private Paint mPaint;
    private int mWidth;
    private int mHeight;
    private int mProgress;
    private int mMaxProgress;
    private int[] mColors;

    public GradientProgressBar(Context context) {
        this(context, null);
    }

    public GradientProgressBar(Context context, AttributeSet attrs) {
        super(context, attrs);
        mPaint = new Paint();
        mPaint.setAntiAlias(true);
        mPaint.setStyle(Paint.Style.FILL);
        mColors = new int[]{Color.RED, Color.YELLOW, Color.GREEN};
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        mWidth = MeasureSpec.getSize(widthMeasureSpec);
        mHeight = MeasureSpec.getSize(heightMeasureSpec);
    }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        float progressWidth = (float) mProgress / mMaxProgress * mWidth;
        LinearGradient gradient = new LinearGradient(0, 0, progressWidth, mHeight, mColors, null, Shader.TileMode.CLAMP);
        mPaint.setShader(gradient);
        canvas.drawRect(0, 0, progressWidth, mHeight, mPaint);
    }

    public void setProgress(int progress) {
        mProgress = progress;
        invalidate();
    }

    public void setMaxProgress(int maxProgress) {
        mMaxProgress = maxProgress;
    }

    public void setColors(int[] colors) {
        mColors = colors;
    }
}

你可以在布局文件中使用这个自定义 View，例如：

<com.example.GradientProgressBar
    android:id="@+id/progress_bar"
    android:layout_width="match_parent"
    android:layout_height="10dp"
    app:colors="@array/progress_colors"
    app:maxProgress="100"
    app:progress="50" />

其中，`colors` 属性是一个颜色数组，`maxProgress` 属性是最大进度值，`progress` 属性是当前进度值。