MainActivity
public class MainActivity
extends Activity {
private Button
btn;
private SeismicWaveView
seismicWaveView;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState)
;
setContentView(R.layout.
activity_main)
;
btn = (Button) findViewById(R.id.
button)
;
btn.setText(
"开始")
;
seismicWaveView = (SeismicWaveView) findViewById(R.id.
seismicwaveview)
;
//控制地震波的按钮
btn.setOnClickListener(
new View.OnClickListener() {
@Override
public void onClick(View v) {
if (
seismicWaveView.isStarting()) {
btn.setText(
"继续")
;
seismicWaveView.stop()
;
}
else {
btn.setText(
"停止")
;
seismicWaveView.start()
;
}
}
})
;
}
}
SeismicWaveView
public class SeismicWaveView extends View {
private Paint paint;
private int maxWidth = 260;
private boolean isStarting = false;
private List<String> alphaList = new ArrayList<String>();
private List<String> startWidthList = new ArrayList<String>();
public SeismicWaveView(Context context) {
super(context);
init();
}
public SeismicWaveView(Context context, AttributeSet attrs) {
super(context, attrs);
init();
}
public SeismicWaveView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
init();
}
private void init() {
paint = new Paint();
paint.setColor(Color.GRAY);//此处颜色可以改为自己喜欢的
alphaList.add("260");//圆心的不透明度
startWidthList.add("0");
}
@Override
public void onDraw(Canvas canvas) {
super.onDraw(canvas);
setBackgroundColor(Color.TRANSPARENT);//颜色：完全透明
//依次绘制 同心圆
for (int i = 0; i < alphaList.size(); i++) {
int alpha = Integer.parseInt(alphaList.get(i));
int startWidth = Integer.parseInt(startWidthList.get(i));
paint.setAlpha(alpha);
canvas.drawCircle(getWidth() / 2, getHeight() / 2, startWidth,paint);
//同心圆扩散
if (isStarting && alpha > 0 && startWidth < maxWidth)
{
alphaList.set(i, (alpha-1)+"");
startWidthList.set(i, (startWidth+1)+"");
}
}
if (isStarting&&Integer.parseInt(startWidthList.get(startWidthList.size() - 1)) == maxWidth / 5) {
alphaList.add("260");
startWidthList.add("0");
}
//同心圆数量达到6个，删除最外层圆
if(isStarting&&startWidthList.size()==4)
{
startWidthList.remove(0);
alphaList.remove(0);
}
//刷新界面
invalidate();
}
//地震波开始/继续进行
public void start() {
isStarting = true;
}
//地震波暂停
public void stop() {
isStarting = false;
}
public boolean isStarting() {
return isStarting;
}
}
MainActivity布局
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
>
<Button
android:id="@+id/button"
android:layout_width="match_parent"
android:layout_height="wrap_content"/>
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="wrap_content" >
>
<com.example.maleking.platform.SeismicWaveView
android:id="@+id/seismicwaveview"
android:layout_width="match_parent"
android:layout_height="match_parent" />
<ImageView
android:id="@+id/imageView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:layout_centerVertical="true"
android:src="@mipmap/ic_launcher" />
</RelativeLayout>
</LinearLayout>
