属性动画的用法 以及ButterKnife的用法

1.属性动画 2.黄油刀ButterKnife

什么是属性动画：属性动画是从3.0及以后出现的（如果要兼容低版本，可以使用一个民间版第三方的一个jar NineOldAndroid.jar,用法跟系统的用法差不多）。
不断地控制控件的属性变化达到动画的效果，一般我们是一些组合的属性动画达到复杂的效果。

属性动画的用法

1.在xml文件中添加控件

 2.在ActivityJava文件中设置按钮的点击事件

public class MainActivity extends AppCompatActivity implements View.OnClickListener {
    private Button btn_1;
    private Button btn_2;
    private Button btn_3;
    private Button btn_4;
    private Button btn_5;
    private ImageView img;
    private LinearLayout lv_root;
    int width,height;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        btn_1=findViewById(R.id.btn_1);
        btn_2=findViewById(R.id.btn_2);
        btn_3=findViewById(R.id.btn_3);
        btn_4=findViewById(R.id.btn_4);
        btn_5=findViewById(R.id.btn_5);
        img=findViewById(R.id.img);
        lv_root=findViewById(R.id.lv_root);

        btn_1.setOnClickListener(this);
        btn_2.setOnClickListener(this);
        btn_3.setOnClickListener(this);
        btn_4.setOnClickListener(this);
        btn_5.setOnClickListener(this);
    }

    @Override
    public void onClick(View view) {
        switch (view.getId()){
            case R.id.btn_1:
                 
                break;
            case R.id.btn_2:
                
            case R.id.btn_3:
                
                break;
            case R.id.btn_4:
                
                break;
            case R.id.btn_5:
                
                break;
        }
    }
}

3.设置图片的移动动画，（这里是从上到下移动）

switch (view.getId()){
            case R.id.btn_1:
                 width = lv_root.getWidth();
                 height = lv_root.getHeight();
                ValueAnimator valueAnimator = ValueAnimator.ofInt(0, height / 4, height / 2, height / 4 * 3, height);
                valueAnimator.setDuration(3000L);
                valueAnimator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
                    @Override
                    public void onAnimationUpdate(ValueAnimator valueAnimator) {
                        int y= (Integer) valueAnimator.getAnimatedValue();
                        int x=width/2;
                        moveView(img,x,y);
                    }
                });
                valueAnimator.setInterpolator(new LinearInterpolator());
                valueAnimator.start();
                break;

4.设置图片的旋转缩放动画

case R.id.btn_3:
                AnimatorSet scaleSet=new AnimatorSet();
                ValueAnimator setAnim=ValueAnimator.ofFloat(1.0f,0.5f,1.2f,1.0f,0.6f,1.2f,1.0f);
                setAnim.setDuration(2000l);
                ValueAnimator ra=ValueAnimator.ofInt(0,360);
                ra.setDuration(2000l);
                setAnim.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
                    @Override
                    public void onAnimationUpdate(ValueAnimator valueAnimator) {
                        float scale= (float)valueAnimator.getAnimatedValue();
                        img.setScaleX(scale);
                        img.setScaleY(scale);
                    }
                });
                ra.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
                    @Override
                    public void onAnimationUpdate(ValueAnimator valueAnimator) {
                        int rotate=(int)valueAnimator.getAnimatedValue();
                        img.setRotation(rotate);
                    }
                });
                scaleSet.playTogether(setAnim,ra);
                //scaleSet.play(setAnim).after(ra);
                scaleSet.start();

5.设置图片的旋转渐变动画

case R.id.btn_4:
                ValueAnimator raValue=ValueAnimator.ofInt(0,360);
                raValue.setDuration(1000l);
                raValue.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
                    @Override
                    public void onAnimationUpdate(ValueAnimator valueAnimator) {
                        int rotate= (int) valueAnimator.getAnimatedValue();
                        img.setRotation(rotate);
                        float alpha=valueAnimator.getAnimatedFraction();
                        img.setAlpha(alpha);
                    }
                });
                raValue.setInterpolator(new DecelerateInterpolator());
                raValue.start();
                break;

1.引入依赖

implementation 'com.jakewharton:butterknife:10.2.3'// 添加此依赖 annotationProcessor 'com.jakewharton:butterknife-compiler:10.2.3'// 添加此规则

2.在java文件中使用，绑定控件

@BindView(R.id.button1)
    Button button1;
    @BindView(R.id.button2)
    Button button2;
    @BindView(R.id.button3)
    Button button3;
    @BindView(R.id.button4)
    Button button4;

3.在orCreate中启动绑定

@Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main2);

        ButterKnife.bind(this);
    }

4.设置点击事件

 @OnClick({R.id.button1,R.id.button2,R.id.button3,R.id.button4})
    public void onClick(View v){
        switch (v.getId()){
            case R.id.button1:
                Toast.makeText(this, "按钮1", Toast.LENGTH_SHORT).show();
                break;
            case R.id.button2:
                Toast.makeText(this, "按钮2", Toast.LENGTH_SHORT).show();
                break;
            case R.id.button3:
                Toast.makeText(this, "按钮3", Toast.LENGTH_SHORT).show();
                break;
            case R.id.button4:
                Toast.makeText(this, "按钮4", Toast.LENGTH_SHORT).show();
                break;

        }
    }