public MaskedTextView(Context context, AttributeSet attrs) {
super(context, attrs);
p = new Paint(Paint.ANTI_ALIAS_FLAG);
p.setTextSize(25);
p.setColor(Color.GREEN);
pReplace = new Paint(p);
pReplace.setColor(Color.BLUE);
pReplace.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.DST_OVER));
pMask = new Paint();
int lightGradientColor = getResources().getColor(R.color.dailyGoalLowLight);
int darkGradientColor = getResources().getColor(R.color.dailyGoalLowDark);
Shader shader = new LinearGradient(0, 0, 150, 0, lightGradientColor, darkGradientColor, Shader.TileMode.CLAMP);
pMask.setShader(shader);
pMask.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.CLEAR));
}
@Override
public void onDraw(Canvas canvas) {
super.onDraw(canvas);
canvas.save();
if (!Utils.isEmpty(sText)) {
canvas.drawText(sText, 150, getHeight() / 2, p);
canvas.drawRect(0, 0, 180, getHeight(), pMask);
canvas.drawText(sText, 150, getHeight()/2, pReplace);
}
canvas.restore();
}
这将导致:
关闭,这里的问题是设置
pMask.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.CLEAR));
时水平线性渐变不显示。如果我把那一行注释掉,会得到以下结果:
再次关闭,但现在线性渐变完全覆盖文本。有人能帮我解决我在这里丢失的东西吗?有没有更好的方法来达到这个效果?
最佳答案
PorterDuff.Mode.SRC_IN
也许会有帮助。
应该调用setLayerType(View.LAYER_TYPE_SOFTWARE, null);
来使用SRC_IN
。
public class MaskedTextView extends View {
private final Paint pLeftBg;
private final Paint pText;
private final Paint pRightMask;
private String mText = "web";
public MaskedTextView(Context context, AttributeSet attrs) {
super(context, attrs);
pLeftBg = new Paint();
int lightGradientColor = ContextCompat.getColor(getContext(), R.color.dailyGoalLowLight);
int darkGradientColor = ContextCompat.getColor(getContext(), R.color.dailyGoalLowDark);
Shader shader = new LinearGradient(0, 0, 150, 0, lightGradientColor, darkGradientColor, Shader.TileMode.CLAMP);
pLeftBg.setShader(shader);
pText = new Paint(Paint.ANTI_ALIAS_FLAG);
pText.setTextSize(50);
pText.setColor(Color.WHITE);
pRightMask = new Paint();
pRightMask.setColor(ContextCompat.getColor(getContext(), R.color.dailyGoalLowLight));
pRightMask.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_IN));
setLayerType(View.LAYER_TYPE_SOFTWARE, null);
}
@Override
public void onDraw(Canvas canvas) {
super.onDraw(canvas);
canvas.save();
canvas.drawRect(0, 0, 100, getHeight(), pLeftBg);
canvas.drawText(mText, 50, getHeight() / 2, pText);
canvas.drawRect(100, 0, getWidth(), getHeight(), pRightMask);
canvas.restore();
}
}
输出: