廢話不多說 先上圖(用AS錄製的 轉換工具不是很好 所以看得效果不是很好)


gif5新文件.gif

Activity 代碼

public class ShapeDrawableActivity extends AppCompatActivity {
    private ImageView ivLightbeam;

    private ObjectAnimator radarScanAnim;   // 掃描動畫

    private int width;
    private int height;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_shape_drawable);
        ivLightbeam = (ImageView) findViewById(R.id.ivLightbeam);
    }


    @Override
    protected void onResume() {
        super.onResume();
        startScan();
    }

    @Override
    public void onWindowFocusChanged(boolean hasFocus) {
        super.onWindowFocusChanged(hasFocus);
        if (height == 0 || width == 0) {            //獲取屏幕長、寬
            width = ScreenUtils.getScreenWidth(this);
            height = ScreenUtils.getScreenHeight(this);            //根據屏幕長、寬計算掃描圓的直徑
            int diameter = (int) Math.sqrt(Math.pow(height, 2) + Math.pow(width, 2));            //修改光束的大小,使光束可以掃描到整個屏幕
            FrameLayout.LayoutParams layoutParams = new FrameLayout.LayoutParams(diameter, diameter);
            ivLightbeam.setLayoutParams(layoutParams);            //將掃描光束的中心移至屏幕內容中心
            int offsetX = (width - diameter) / 2;
            int offsetY = (height - diameter) / 2 + ScreenUtils.getStatusHeight(this) / 2;
            ivLightbeam.setX(offsetX);
            ivLightbeam.setY(offsetY);
        }
    }

    @Override
    protected void onPause() {
        super.onPause();
        stopScan();
    }    // 開始掃描

    private void startScan() {
        radarScanAnim = ObjectAnimator.ofFloat(ivLightbeam, "rotation", 0f, 360f);
        radarScanAnim.setDuration(2000);    //2秒掃描一圈
        radarScanAnim.setInterpolator(new LinearInterpolator());
        radarScanAnim.setRepeatCount(ObjectAnimator.INFINITE);//循環掃描

        ivLightbeam.setVisibility(View.VISIBLE);
        radarScanAnim.start();
    }   // 停止掃描

    private void stopScan() {
        ivLightbeam.setVisibility(View.GONE);
        radarScanAnim.end();
    }
}

Activity 布局文件

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#FA000000"
    android:clipToPadding="false"
    android:fitsSystemWindows="true">

    <ImageView
        android:id="@+id/ivWave"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_margin="5dp"
        android:src="@drawable/wave" />

    <ImageView
        android:id="@+id/ivLightbeam"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:src="@drawable/light_beam" />

</FrameLayout>

繪製掃描光束

<shape
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="oval">

    <size
        android:width="500dp"
        android:height="500dp" />

    <gradient
        android:endColor="#AAAAAAAA"
        android:startColor="#00000000"
        android:type="sweep"
        />
</shape>

繪製雷達波紋

<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
    <item>
        <!--最外層圓圈-->
        <shape android:shape="oval">
            <solid android:color="#10FFFFFF" />
            <size
                android:width="600dp"
                android:height="600dp" />
            <stroke
                android:color="#10B8B8B8"
                android:dashWidth="1dp" />
        </shape>
    </item>

    <item
        android:bottom="100dp"
        android:left="100dp"
        android:right="100dp"
        android:top="100dp">
        <!--最中間層圓圈-->
        <shape android:shape="oval">
            <solid android:color="#1CFFFFFF" />
            <stroke
                android:color="#1CB8B8B8"
                android:dashWidth="1dp" />
        </shape>
    </item>

    <item
        android:bottom="200dp"
        android:left="200dp"
        android:right="200dp"
        android:top="200dp">

        <!--最中心圓圈-->
        <shape android:shape="oval">
            <solid android:color="#2CFFFFFF" />
            <stroke
                android:color="#2CB8B8B8"
                android:dashWidth="1dp" />
        </shape>
    </item>
</layer-list>