Android：数字键注册退格键 [英] Android: Numeric key register backspace pressed

问题描述

我有一个EditText只接受如下定义的数字：

I have an EditText which only accepts numeric numbers defined like this:

<EditText android:id="@+id/routeInit_price" 
    android:layout_height="wrap_content"
    android:layout_width="120dp"
    android:layout_gravity="center_horizontal"
    android:lines="1"
    android:inputType="numberDecimal"/>

我验证是否有如下所示的有效输入来启用/禁用按钮。但是，我没有在退格/删除按钮按下的事件上收到一个事件。我该如何解决？因为当EditText为空时，该按钮应该是被打开的。

I am validating if there is a valid input like below to enable/disable a button. However, I doesn't receive an event on the backspace/delete button pressed event. How can I fix that? Because when the EditText is empty the button should be diabled.

EditText priceField = (EditText)findViewById(R.id.routeInit_price);
priceField.setOnKeyListener(new View.OnKeyListener() {
        @Override
        public boolean onKey(View view, int keyCode, KeyEvent keyEvent) {
            if(keyEvent.getAction() == KeyEvent.ACTION_UP)
            {
                if(((EditText)view).getText().toString().length() > 0)
                    ready.setEnabled(true);

                else
                    ready.setEnabled(false);
            }

            return false;
        }
});

推荐答案

尝试这个

priceField.addTextChangedListener(new TextWatcher() {

        @Override
        public void onTextChanged(CharSequence s, int start, int before, int count) {

            if(priceField.getText().toString().length() > 0)
                ready.setEnabled(true);

            else
                ready.setEnabled(false);
        }

        @Override
        public void beforeTextChanged(CharSequence s, int start, int count, int after) {

        }

        @Override
        public void afterTextChanged(Editable s) {

        }
    });

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