写一个class继承view
package com.example.myapplication.login;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.support.annotation.Nullable;
import android.util.AttributeSet;
import android.view.View;
public class CircleIView extends View {
public int width;
public int height;
public Paint paint;
public CircleIView(Context context) {
super(context);
}
public CircleIView(Context context, @Nullable AttributeSet attrs) {
super(context, attrs);
paint=new Paint();
paint.setColor(Color.YELLOW);
}
public CircleIView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
}
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
canvas.drawCircle(width/2,height/2,50,paint);
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
width=getMeasuredWidth();
height=getMeasuredHeight();
}
}
在Activity展示
ObjectAnimator objectAnimator=ObjectAnimator.ofFloat(imageView,"translationY",0f,400f);
objectAnimator.setDuration(5000);
objectAnimator.start();