5月14日学习日志

今天学习了在指定的地方播放帧动画。

关键代码为：

public class FrameView extends ImageView {

    private AnimationDrawable anim;

    public FrameView(Context context) {
        super(context);
    }

    public FrameView(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    public FrameView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
    }

    public void setAnim(AnimationDrawable anim){
        this.anim = anim;
    }

    public void setLocation(int top,int left){
        this.setFrame(left,top,left + 200,top + 200);
    }

    @Override
    protected void onDraw(Canvas canvas) {
        try{
            //反射调用AnimationDrawable里的mCurFrame值
            Field field = AnimationDrawable.class
                    .getDeclaredField("mCurFrame");
            field.setAccessible(true);
            int curFrame = field.getInt(anim);// 获取anim动画的当前帧
            if (curFrame == anim.getNumberOfFrames() - 1)// 如果已经到了最后一帧
            {
                //让该View隐藏
                setVisibility(View.INVISIBLE);
            }
        }catch (Exception e){e.printStackTrace();}
        super.onDraw(canvas);
    }
}

public class MainActivity extends AppCompatActivity {

    private FrameView fView;
    private AnimationDrawable anim = null;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        FrameLayout fly = new FrameLayout(this);
        setContentView(fly);
        fView = new FrameView(this);
        fView.setBackgroundResource(R.anim.anim_zhuan);
        fView.setVisibility(View.INVISIBLE);
        anim = (AnimationDrawable) fView.getBackground();
        fView.setAnim(anim);
        fly.addView(fView);
        fly.setOnTouchListener(new View.OnTouchListener() {
            @Override
            public boolean onTouch(View v, MotionEvent event) {
                //设置按下时才产生动画效果
                if(event.getAction() == MotionEvent.ACTION_DOWN){
                    anim.stop();
                    float x = event.getX();
                    float y = event.getY();
                    fView.setLocation((int) y - 40,(int)x-20);  //View显示的位置
                    fView.setVisibility(View.VISIBLE);
                    anim.start();    //开启动画
                }
                return false;
            }
        });
    }
}