Android 长方形色盘

以下是一个Android长方形色盘的实现方法：
1.在res/drawable文件夹下创建一个selector.xml文件，代码如下：

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:state_checked="false">
        <shape android:shape="rectangle">
            <stroke android:width="1dp" android:color="#FFD2D2" />
            <corners android:radius="1dp"/>
            <gradient android:angle="0" android:startColor="#FF3333" android:endColor="#F8F8F8" android:type="linear" />
        </shape>
    </item>
</selector>

2.在布局文件中添加自定义的RectangleColorSelectorView，代码如下：

<com.example.colorselfdefinedemo.RectangleColorSelectorView
    android:id="@+id/self_view"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content" />

3.创建RectangleColorSelectorView类并继承View类，代码如下：

public class RectangleColorSelectorView extends View {
    private Paint mPaint;
    private int mWidth;
    private int mHeight;

    public RectangleColorSelectorView(Context context) {
        super(context);
        init();
    }

    public RectangleColorSelectorView(Context context, AttributeSet attrs) {
        super(context, attrs);
        init();
    }

    public RectangleColorSelectorView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        init();
    }

    private void init() {
        mPaint = new Paint();
        mPaint.setStyle(Paint.Style.FILL);
    }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        mWidth = getWidth();
        mHeight = getHeight();
        LinearGradient linearGradient = new LinearGradient(0, 0, mWidth, 0, new int[]{Color.RED, Color.YELLOW, Color.GREEN, Color.CYAN, Color.BLUE, Color.MAGENTA, Color.RED}, null, Shader.TileMode.CLAMP);
        mPaint.setShader(linearGradient);
        canvas.drawRect(0, 0, mWidth, mHeight, mPaint);
    }
}