Tv開發(fā)，最重要的當(dāng)然是焦點(diǎn)框的移動(dòng)氛悬，有了焦點(diǎn)框我們才能知道當(dāng)前選中的是哪一個(gè)，我們來看下效果圖：
焦點(diǎn)框移動(dòng)
那它是怎么實(shí)現(xiàn)的呢凄诞，我們一起來看下圆雁。
原理
布局上使用一個(gè)view，背景是.9圖片做焦點(diǎn)框帆谍，選中一個(gè)控件的時(shí)候把這個(gè)view移動(dòng)選中的控件的位置。怎么樣轴咱，是不是很簡(jiǎn)單汛蝙，行動(dòng)起來。先看下布局
codeing
布局：
<?xml version="1.0" encoding="utf-8"?>
<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"
android:background="@color/colorAccent"
tools:context=".MainActivity">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical">
<FrameLayout
android:id="@+id/id_fl"
android:layout_width="880dp"
android:layout_height="76dp"
android:layout_marginLeft="208dp"
android:layout_marginTop="9dp"
android:focusable="true">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_vertical"
android:layout_marginLeft="40dp"
android:text="第一行"
android:textSize="28sp" />
</FrameLayout>
<FrameLayout
android:id="@+id/id_fl_2"
android:layout_width="880dp"
android:layout_height="76dp"
android:layout_marginLeft="208dp"
android:layout_marginTop="9dp"
android:focusable="true">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_vertical"
android:layout_marginLeft="40dp"
android:text="第二行"
android:textSize="28sp" />
</FrameLayout>
</LinearLayout>
<View
android:id="@+id/id_focus"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:background="@drawable/settings_selector"
android:visibility="gone" />
</FrameLayout>
最底下的View就是我們要用到的焦點(diǎn)框
代碼
import android.app.Activity;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.FrameLayout;
public class MainActivity extends Activity implements View.OnFocusChangeListener{
private String TAG ="qkmin";
private int Layout1 = R.id.id_fl;
private int Layout2 = R.id.id_fl_2;
private View onFousView;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
initViews();
}
private void initViews() {
FrameLayout frameLayout=findViewById(Layout1);
FrameLayout frameLayout2=findViewById(Layout2);
onFousView = findViewById(R.id.id_focus);
//設(shè)置焦點(diǎn)變化監(jiān)聽
frameLayout.setOnFocusChangeListener(this);
frameLayout2.setOnFocusChangeListener(this);
}
@Override
public void onFocusChange(View v, boolean hasFocus) {
if (hasFocus){
Log.i(TAG,"onFocusChange"+v.getId());
//設(shè)置焦點(diǎn)框的位置和動(dòng)畫
Tools.focusAnimator(v,onFousView);
}
}
}
我們來看下Tools 這個(gè)類：
import android.animation.Animator;
import android.animation.AnimatorSet;
import android.animation.ObjectAnimator;
import android.animation.ValueAnimator;
import android.view.View;
import android.view.ViewGroup;
public class Tools {
private static int mFocusWidth;
private static int mFoucsHeight;
public static void focusAnimator(View v, View onFousView) {
focusAnimator(v, onFousView, -1, 0, 0);
}
public static void focusAnimator(View parentView, final View focusView, int scrollY, int offSetX, int offSetY) {
int[] fromLocation = new int[2];
focusView.getLocationOnScreen(fromLocation);
int fromWidth = focusView.getWidth();
int fromHeight = focusView.getHeight();
float fromX = fromLocation[0];
float fromY = fromLocation[1];
int[] toLocation = new int[2];
parentView.getLocationOnScreen(toLocation);
int toWidth = parentView.getWidth() + offSetX;
int toHeight = parentView.getHeight() + offSetY;
float toX = toLocation[0] - offSetX / 2;
float toY = toLocation[1] - offSetY / 2;
if (scrollY == -1) {
if (focusView.getVisibility() == View.GONE)
focusView.setVisibility(View.VISIBLE);
}
AnimatorSet animatorSet = new AnimatorSet();
ObjectAnimator translateXAnimator = ObjectAnimator.ofFloat(focusView, "x", fromX, toX);
translateXAnimator.addListener(new Animator.AnimatorListener() {
@Override
public void onAnimationStart(Animator animation) {
}
@Override
public void onAnimationRepeat(Animator animation) {
}
@Override
public void onAnimationEnd(Animator animation) {
if (focusView.getVisibility() == View.GONE) {
focusView.setVisibility(View.VISIBLE);
}
}
@Override
public void onAnimationCancel(Animator animation) {
if (focusView.getVisibility() == View.GONE)
focusView.setVisibility(View.VISIBLE);
}
});
ObjectAnimator translateYAnimator = ObjectAnimator.ofFloat(focusView, "y", fromY, toY);
ValueAnimator scaleWidthAnimator = ObjectAnimator.ofFloat(focusView, "width", fromWidth, toWidth);
scaleWidthAnimator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
@Override
public void onAnimationUpdate(ValueAnimator animation) {
float width = (Float) animation.getAnimatedValue();
mFocusWidth = (int) width;
ViewGroup.LayoutParams layoutParams = focusView.getLayoutParams();
layoutParams.width = mFocusWidth;
layoutParams.height = mFoucsHeight;
focusView.setLayoutParams(layoutParams);
}
});
ValueAnimator scaleHeightAnimator = ObjectAnimator.ofFloat(focusView, "height", fromHeight, toHeight);
scaleHeightAnimator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
@Override
public void onAnimationUpdate(ValueAnimator animation) {
float height = (Float) animation.getAnimatedValue();
mFoucsHeight = (int) height;
ViewGroup.LayoutParams layoutParams = focusView.getLayoutParams();
layoutParams.width = mFocusWidth;
layoutParams.height = mFoucsHeight;
focusView.setLayoutParams(layoutParams);
}
});
animatorSet.playTogether(translateXAnimator, translateYAnimator, scaleWidthAnimator, scaleHeightAnimator);
animatorSet.setDuration(150);
animatorSet.start();
}
}
主要方法是focusAnimator（）朴肺，首先獲取focusView的寬窖剑、高，以及x ,y 坐標(biāo)戈稿，在得到獲取焦點(diǎn)的view的寬西土、高，以及x ,y 坐標(biāo)鞍盗，最會(huì)設(shè)置動(dòng)畫需了。這樣就Ok了跳昼。
下面是項(xiàng)目地址
https://gitee.com/love_k/FocusTest.git
