Analysis of character filtering function of TextView of Android programming _android

This article analyzes the TextView character filtering function of Android programming. Share to everyone for your reference, specific as follows:

TextView can be set to accept a wide variety of characters, by filtering the specified characters to meet the input and display requirements of different applications.

Through XML configuration:

Android:inputtype

Number accepts integer input
numbersigned Accept signed integer input
Numberdecimal accepts integer and decimal input

Android:digits

Specifies that a fixed number, such as android:digits= "012345", is accepted and only the input of 0~5 digits is accepted

Android:numberic

Integers Accept integer input
Signed Accept signed integer input
Decimal accepts integer and decimal input

Setting through Java code

In fact, the above 3 properties, the function is a bit repetitive, and ultimately through the Java code to TextView settings KeyListener

KeyListener is an interface that provides monitoring of input keyboard keys

Inputfilter is an interface that provides filtering on characters

Android provides the numberkeylistener that implements KeyListener and Inputfilter, and Digitskeylistener inherits Numberkeylistener

TextView TV = new TextView (context);
Accept only integer input
keylistener l = new Digitskeylistener (fasle,false);
Accept signed integer input
keylistener l = new Digitskeylistener (true,false);
Accept decimal, Integer input
keylistener l = new Digitskeylistener (false,true);
Accept signed integer/decimal input
keylistener L = new Digitskeylistener (true,true);
Tv.setkeylistener (l);

If you want to achieve a greater degree of freedom of filtering customization, you can write a KeyListener (inherited Basekeylistener) and implement Inputfilter, rewrite the filter () function, in the filter () function can be free filter.

I hope this article will help you with the Android program.