[英]How can I make a button unclickable when there is no text in the Edit Text box?
I know do know how to make it unclickable "button.setEnabled(false);" 我知道确实知道如何使它不可点击“ button.setEnabled(false);” but not sure how to call the function.
但不确定如何调用该函数。 I have tried if(editText.setText()).
我已经尝试过if(editText.setText())。 Any help is appreciated and thanks in advance.
任何帮助表示赞赏,并在此先感谢。
editText.setText() is a void method, you want to get a method that returns something (gettext). editText.setText()是一个无效方法,您想获得一个返回某些内容(gettext)的方法。
String text = editText.getText().toString();
if (text.equals("")) {
// do your stuff
}
您可以使用addTextChangedListener方法将TextWatcher
添加到EditText
并在onTextChanged或afterTextChanged方法中实现所有必要的逻辑以启用/禁用按钮。
yourButton.setEnabled(!yourTextView.getText().toString.isEmpty());
只需一行解决方案。
I think the correct way to do this is to add a on click listener to the edittext
, and from there you monitor the onTextChanged
and disable the button if the string's length is 0. Which should look something like this: 我认为执行此操作的正确方法是将一个on click侦听器添加到
edittext
,然后从那里监视onTextChanged
并在字符串的长度为0时禁用该按钮。看起来应该像这样:
myButton = (Button) findViewById(R.id.button);
myButton.setEnabled(false);
EditText textMessage = (EditText)findViewById(R.id.editText);
textMessage.addTextChangedListener(new TextWatcher() {
@Override
public void afterTextChanged(Editable s) {}
@Override
public void beforeTextChanged(CharSequence s, int start,
int count, int after) {
}
@Override
public void onTextChanged(CharSequence s, int start,int before, int count) {
if(s.length() == 0)
myButton.setEnabled(false);
else
myButton.setEnabled(true);
}
});
you can achive this in two way
before using any aproach you write the code to disable the button in the
oncreate() you set the button clickable false by default.
//1.by using focus change listener
//2.by using TextchangeListener or TextWatcher the threshold to check the condition after the specific length of text
public class MainActivity extends Activity {
private EditText editText;Button button;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
editText= (EditText) findViewById(R.id.editText1);
button= (Button) findViewById(R.id.button1);
button.setEnabled(false);
//1.by using focus change listener
editText.setOnFocusChangeListener(new OnFocusChangeListener(){
@Override
public void onFocusChange(View v, boolean hasFocus) {
if(editText.getText().toString().trim().length()>0)
{ button.setEnabled(true); }
else{ button.setEnabled(false);}
}});
//or
//2.by using TextchangeListener or TextWatcher
editText.addTextChangedListener(new new TextWatcher(){
@Override
public void afterTextChanged(Editable s) {
if(editText.getText().toString().trim().length()>0)
{
button.setEnabled(true);
} else{ button.setEnabled(false);}
/*this function will call on every text entry so use
some threshold so it will be call once and validate
that threshold in if() as condition to make button clickable. */
}
@Override
public void beforeTextChanged(CharSequence s, int start, int count, int after) { }
@Override
public void onTextChanged(CharSequence s, int start, int before, int count) { } });
}
}
my suggestion is if you want to keep track of the letter than go for the addTextChangedListener
else use the focusChangeListener code only
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