RotateAnimation 实现表盘指针转动
RotateAnimation 实现表盘指针转动
最近在做车助手这个项目，遇到这样的一个功能需求：获取车子启动的实时数据让指针转动：
我这里做了一个Demo：demo的原理在于使用onTouchEvent事件，计算手指在屏幕上开始
和结束的位置来作为指针转动的角度，并且跟着手指不断的滑动，指针不断的变化，效果图如下：
代码如下：
主activity：
public class MainActivity extends Activity {
private ImageView pointer;
LayoutInflater inflater;
RotateAnimation rotateAnimation;
Bitmap bitmap;
View view;
float start = 0;
float end = 0;
float distance = 0;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
pointer = (ImageView)findViewById(R.id.pointer_data1);
inflater = LayoutInflater.from(this);
view = inflater.inflate(R.layout.activity_main, null);
bitmap = ((BitmapDrawable) getResources().getDrawable(
R.drawable.point)).getBitmap();
pointer.setImageBitmap(bitmap);
rotateAnimation = new RotateAnimation(start - end,-7.8f,Animation.RELATIVE_TO_SELF,
0.5f,Animation.RELATIVE_TO_SELF,0.5f);
rotateAnimation.setFillAfter(true);
rotateAnimation.setDuration(1); // 持续时间
pointer.startAnimation(rotateAnimation);
}
public boolean onTouchEvent(MotionEvent event) {
if (event.getAction() == MotionEvent.ACTION_DOWN) {
start = event.getY();
}else if (event.getAction() == MotionEvent.ACTION_MOVE) {
end = event.getY();
distance = end - start;
animPlay(start, end);
}if (event.getAction() == MotionEvent.ACTION_UP) {
start = 0;
end = 0;
distance = 0;
}
return super.onTouchEvent(event);
}
public void animPlay(float star, float end) {
pointer.setImageBitmap(null);
bitmap = ((BitmapDrawable) getResources().getDrawable(
R.drawable.point)).getBitmap();
pointer.setImageBitmap(bitmap);
rotateAnimation = new RotateAnimation(start - end,-7.8f,Animation.RELATIVE_TO_SELF,
0.5f,Animation.RELATIVE_TO_SELF,0.5f);
rotateAnimation.setFillAfter(true);
// rotateAnimation.setDuration(10000); // 持续时间
float temp = end - start;
if(temp < 0){
temp = 0 - temp;
}
rotateAnimation.setDuration((long)((temp/360)*1000) ); // 持续时间
pointer.setAnimation(rotateAnimation); // 设置动画
rotateAnimation.startNow();
rotateAnimation = null;
bitmap = null;
}
}
主要布局文件：<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity"
>
<ImageView
android:id="@+id/container_data1"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:src="@drawable/clock" />
<ImageView
android:id="@+id/pointer_data1"
android:src="@drawable/point"
android:layout_width="match_parent"
android:layout_height="match_parent" />
FrameLayout>
图片资源：
clock
point:
Demo下载地址：
http://download.csdn.net/download/lyhdream/5241123