动态创建Android view的绝对位置&view的大小

 

今天的需求是展示一个新功能tip。

效果图：

 

小tip的下箭头要展示在第三个tab的正中间位置，把参数写死是肯定不行的，因为各个手机的分辨率不同，小箭头展示地方部位定，所以开始用计算的方式来实现吧。

 

这是计算小草图。

 

 

 

 

-------------------------------------------------------code------------------------------------------------------------------

 

 

main_tabs.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/word_layout"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
         <!—这里省略了TabHost-->
        <ImageView
            android:id="@+id/word_tip_btn"
            android:layout_width="wrap_content"
            android:layout_alignParentBottom="true"
            android:layout_alignParentRight="true"
            android:layout_marginBottom="58dp"
            android:layout_height="wrap_content"
            android:src="@drawable/word_tip" />
</RelativeLayout>

MainTabsActivity.class

 

public class MainTabsActivity extendsTabActivity implements

       OnCheckedChangeListener {

   public static String MAINTABSACTIVITY_BOTTOM_BROADCASTRECEIVER ="MainTabsActivity_Bottom_BroadCastReceiver";

   private Activity mContext;

 

 

  

 

   private RelativeLayout layout;

 

 

   private ImageView word_tip_btn;

   private SharedPreferences.Editor mEditor;

   private boolean word_flag_state;

   private int tabWidth;

 

   @SuppressWarnings("deprecation")

   @Override

   public void onCreate(Bundle savedInstanceState) {

       super.onCreate(savedInstanceState);

       setContentView(R.layout.main_tabs);

       mContext = this;

      

 

     

       word_tip_btn = findViewById(R.id.word_tip_btn);

       word_tip_btn.post(new Runnable() {

           @Override

           public void run() {

                setViewSize(word_tip_btn);

           }

       });

       if (word_flag_state) {

           word_tip_btn.setVisibility(View.VISIBLE);

       } else {

           word_tip_btn.setVisibility(View.GONE);

       }

   private void setViewSize(ImageView view) {

       tabWidth = mTabHost.getResources().getDisplayMetrics().widthPixels;

       RelativeLayout.MarginLayoutParams lp =(RelativeLayout.MarginLayoutParams) view.getLayoutParams();

       int w2 = view.getMeasuredWidth();

       lp.rightMargin = 3 * tabWidth / 8 - w2 / 2;

        view.setLayoutParams(lp);

    }

}