使用
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:gravity="center"
android:orientation="vertical" >
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:gravity="center"
android:text="普通的TextView"
android:textColor="#00f"
android:textSize="30sp" />
<com.bqt.myview.MyShimmerTextView
android:id="@+id/shimmer_tv"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:background="#000"
android:gravity="center"
android:text="闪烁效果的TextView"
android:textColor="#00f"
android:textSize="30sp" />
</LinearLayout> 代码
public class MyShimmerTextView extends TextView {
/**渲染器,用于显示本例中的颜色效果*/
private LinearGradient mLinearGradient;
/**矩阵,用于确定渲染范围*/
private Matrix mGradientMatrix;
/**渲染的起始位置*/
private int mViewWidth = 0;
/**渲染的终止距离*/
private int mTranslate = 0;
/**是否启动动画*/
private boolean mAnimating = true;
/**多少毫秒刷新一次*/
private int speed = 50;
private Paint mPaint;
public MyShimmerTextView(Context context, AttributeSet attrs) {
super(context, attrs);
mPaint = getPaint();
mGradientMatrix = new Matrix();
}
@SuppressLint("DrawAllocation")
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
mViewWidth = getMeasuredWidth();
//可以尝试一下,使用不同的模式可以得到不同的效果
mLinearGradient = new LinearGradient(0, 0, mViewWidth, 0, new int[] { Color.BLACK, Color.WHITE, Color.BLACK }, null, TileMode.CLAMP);
mPaint.setShader(mLinearGradient);
}
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
if (mAnimating && mGradientMatrix != null) {
mTranslate += mViewWidth / 10;//每次移动屏幕的1/10宽
if (mTranslate > 2 * mViewWidth) {
mTranslate = -mViewWidth;
}
mGradientMatrix.setTranslate(mTranslate, 0);
mLinearGradient.setLocalMatrix(mGradientMatrix);//在指定矩阵上渲染
postInvalidateDelayed(speed);
}
}
@Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
super.onSizeChanged(w, h, oldw, oldh);
Log.i("bqt", w + "--" + h);
}