多对角线背景色

Question

我想要一个如下图所示的可绘制背景。我应该如何创建它？

Answer 1

在您的布局背景中使用 drawable XML 下面，根据您的应用需要更改 drawable XML 下面的颜色。

<?xml version="1.0" encoding="UTF-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item>
        <shape>
            <gradient
                android:startColor="@color/application_background"
                android:endColor="@color/bright_red"
                android:angle="45"/>
        </shape>
    </item>
</selector>

请参阅下文 Link 了解如何更改和使用上述代码。

http://www.singhajit.com/gradient-color-in-android/

Answer 2

您可以扩展目标 Drawable class（也许 ColorDrawable）。然后在draw(Canvas)方法中画一个梯形Path。调整 Paint 的透明度和颜色以改变效果。代码可能如下所示：

public class SDrawable extends ColorDrawable {

    private Path mPath = new Path();
    private Paint mPaint = new Paint(Paint.ANTI_ALIAS_FLAG);

    public SDrawable() {
        init();
    }

    public SDrawable(int color) {
        super(color);
        init();
    }

    private void init(){
        mPaint.setColor(0x33ffffff);
    }

    @Override
    public void draw(Canvas canvas) {
        super.draw(canvas);
        mPath.reset();
        mPath.moveTo(0,0);
        mPath.lineTo(canvas.getWidth()/2+50, 0);
        mPath.lineTo(canvas.getWidth()/2, canvas.getHeight());
        mPath.lineTo(0, canvas.getHeight());
        mPath.lineTo(0, 0);
        canvas.drawPath(mPath, mPaint);
    }

}

多对角线背景色

Multiple diagonal background color

android

android-drawable