自定义的类
package bwie.com.zdybo;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Path;
import android.util.AttributeSet;
import android.view.View;
public class zdy extends View {
private Paint mTopPaint;
private Paint mBottomPaint;
private Path mPathTop;
private Path mPathBotom;
private float φ;
public zdy(Context context) {
this(context,null);
}
public zdy(Context context, AttributeSet attrs) {
this(context, attrs,0);
}
public zdy(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
init(context);
}
private void init(Context context) {
mTopPaint = new Paint();
mTopPaint.setColor(Color.BLUE);
mTopPaint.setAntiAlias(true);
mBottomPaint = new Paint();
mBottomPaint.setColor(Color.BLUE);
mBottomPaint.setAntiAlias(true);
mBottomPaint.setAlpha(60);
mPathTop = new Path();
mPathBotom = new Path();
}
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
mPathTop.reset();
mPathBotom.reset();
mPathTop.moveTo(getLeft(),getBottom());
mPathBotom.moveTo(getLeft(),getBottom());
double mY = Math.PI * 2 /getWidth();
φ-=0.1f;
for (float x=0;x<=getWidth();x+=20){
mPathTop.lineTo(x, (float) (10*Math.cos(mY*x+φ)+15));
mPathBotom.lineTo(x, (float) (10*Math.sin(mY*x+φ)));
}
int width= getWidth();
mPathTop.lineTo(width,getBottom());
mPathBotom.lineTo(width,getBottom());
canvas.drawPath(mPathTop,mTopPaint);
canvas.drawPath(mPathBotom,mBottomPaint);
postInvalidateDelayed(20);
}
}
mainactivity
package bwie.com.zdybo;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.Gravity;
import android.view.View;
import android.widget.FrameLayout;
import android.widget.ImageView;
public class MainActivity extends AppCompatActivity {
private zdy zdy;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
zdy = findViewById(R.id.zdy);
}
}