向 TextView 添加点，就像在收据中一样

Question

我想在收据中实现类似产品列表的功能：
面包...................................... ...... 20
牛奶 ................................................ . 10 块
果酱饼干 .................................. 15
智能手机 10GB 3GHz
1GB RAM NFC 10MPx
相机 .................. ………………400

物品名称（面包，牛奶）我认为它应该是一个TextView，我需要用点填充。
金钱 (20, 10) 是另一个TextView应该与屏幕右侧对齐的货币。

有什么想法如何做到这一点？也许我需要继承该类TextView并重写 onDraw() ？
提前谢谢了！

Answer 1

我有解决办法。也许它会对某人有所帮助。

1. 文件 check_info_item.xml：

   <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
         android:layout_width="match_parent"
         android:layout_height="match_parent"
         android:orientation="horizontal">
   <RelativeLayout android:layout_width="match_parent"
             android:layout_height="wrap_content">
   
   <TextView android:layout_height="wrap_content"
             android:layout_width="wrap_content"
             android:id="@+id/txt_fake_value"
             android:textSize="18dp"
             android:textColor="@android:color/transparent"
             android:layout_alignParentRight="true"/>
   <example.com.CheckInfoTextView android:layout_height="wrap_content"
             android:layout_width="match_parent"
             android:id="@+id/txt_fake_info"
             android:textSize="18dp"
             android:textColor="@android:color/transparent"
             android:layout_alignParentLeft="true"
             android:layout_toLeftOf="@id/txt_fake_value"/>
   <TextView android:layout_height="wrap_content"
             android:layout_width="wrap_content"
             android:id="@+id/txt_check_info_value"
             android:text=""
             android:textSize="18dp"
             android:textColor="#000"
             android:layout_alignParentRight="true"
             android:layout_alignBottom="@id/txt_fake_info"/>
   <example.com.CheckInfoTextView
           android:layout_height="wrap_content"
           android:layout_width="match_parent"
           android:textSize="18dp"
           android:textColor="#000"
           android:id="@+id/txt_check_info"
           android:text=""
           android:layout_alignParentLeft="true"
           android:layout_toLeftOf="@id/txt_check_info_value"/>
   </RelativeLayout>
   </LinearLayout>
   

2. 填充信息字段的代码（在活动中）：

       View row = getLayoutInflater().inflate(R.layout.check_info_item, null);
       //Fake fields needed to align base fields in the xml file
       TextView txtFakeValue = (TextView) row.findViewById(R.id.txt_fake_value);
       txtFakeValue.setText(String.valueOf(pair.second));
   
       TextView txtFake = (TextView) row.findViewById(R.id.txt_fake_info);
       txtFake.setText(pair.first);
   
       TextView txtValue = (TextView) row.findViewById(R.id.txt_check_info_value);
       txtValue.setText(String.valueOf(pair.second));
   
       TextView txtTitle = (TextView) row.findViewById(R.id.txt_check_info);
       txtTitle.setText(pair.first);
   

3. 和 CheckInfoTextView：

   public class CheckInfoTextView extends TextView {
   
   
       public CheckInfoTextView(Context context) {
           super(context);
       }
   
       public CheckInfoTextView(Context context, AttributeSet attrs) {
           super(context, attrs);
       }
   
       public CheckInfoTextView(Context context, AttributeSet attrs, int defStyle) {
           super(context, attrs, defStyle);
       }
   
       @Override
       public void onWindowFocusChanged(boolean hasWindowFocus) {
           super.onWindowFocusChanged(hasWindowFocus);
           if(!hasWindowFocus) return;
   
           int requiredDots = getRequiredDotsNumber();
           if(requiredDots == 0) {
               String text = getText().toString();
               StringBuilder result = new StringBuilder();
               result.append(text.substring(0, text.lastIndexOf(' ')));
               result.append("\n");
               result.append(text.substring(text.lastIndexOf(' ') + 1));
               setText(result.toString());
   
               requiredDots = getRequiredDotsNumber();
           }
           String dots = "";
           for (int i = 0; i < requiredDots; ++i) {
               dots += " .";
           }
           setText(getText() + dots);
       }
   
       private int getRequiredDotsNumber() {
           final int width = getWidth();
           final int lastLineWidth = (int) getLayout().getLineWidth(getLineCount() - 1);
           final int availableWidthForDots = width - lastLineWidth;
           final int widthOfOneDot = getWidthOfOneDot();
           final int widthOfTwoDotsWithSpace = getWidthOfTwoDotsWithSpace();
           final int widthOfSpace = widthOfTwoDotsWithSpace - (widthOfOneDot * 2);
           final int widthOfDotWithSpace = widthOfSpace + widthOfOneDot;
           int numberOfDots = availableWidthForDots / widthOfDotWithSpace;
           return numberOfDots;
       }
   
       private int getWidthOfTwoDotsWithSpace() {
          return getStringWidth(". .");
       }
   
       private int getWidthOfOneDot() {
          return getStringWidth(".");
       }
   
       private int getStringWidth(String text) {
           Rect dotBounds = new Rect();
           getPaint().getTextBounds(text,0,text.length(),dotBounds);
           return dotBounds.width();
       }
   }