在Android Studio的编辑文本中自动添加美元符号($)

例
$500强

编辑：

在使用编辑文本时(点击时)应该添加$.货币将以加元计算.然而,美元符号将作为该领域的提醒

private EditText yourEditText;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    setContentView(R.layout.main);
    yourEditText = (EditText) findViewById(R.id.yourEditTextId);

    yourEditText.addTextChangedListener(new TextWatcher() {
      @Override
      public void afterTextChanged(Editable s) {
        yourEditText.setText("$" + yourEditText.getText().toString());
      }
      @Override
      public void beforeTextChanged(CharSequence s, int start, int count, int after) {}
      @Override
      public void onTextChanged(CharSequence s, int start, int before, int count) {}
   });
}