Android Getting Started Tutorial | EditText User Input

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EditText listens for carriage return

When using EditText, sometimes we need to monitor the input carriage return to perform some operations. Or you need to change the carriage return to "Search", "Send" or "Complete" etc.

EditText provides us with an attribute imeOptions to replace the appearance of the enter key in the soft keyboard. For example, actionGo will change the appearance to "Go". Need to be set at the same time android:inputType="text".

<EditText
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:imeOptions="actionGo"
    android:inputType="text" />

Several commonly used attributes and replaced text appearance:

Attributes	illustrate	Corresponds to static variables
actionUnspecified	unspecified	EditorInfo.IME_ACTION_UNSPECIFIED
actionNone	action	EditorInfo.IME_ACTION_NONE
actionGo	go to	EditorInfo.IME_ACTION_GO
actionSearch	search	EditorInfo.IME_ACTION_SEARCH
actionSend	send	EditorInfo.IME_ACTION_SEND
actionNext	Next item	EditorInfo.IME_ACTION_NEXT
actionDone	Finish	EditorInfo.IME_ACTION_DONE

The setting method can be set in the layout file android:imeOptions="actionNext"or in the codemUserEdit.setImeOptions(EditorInfo.IME_ACTION_NEXT);

Next, set the listening event for the Enter keysetOnEditorActionListener

et1.setOnEditorActionListener(mOnEditorActionListener);
    // ......
    private TextView.OnEditorActionListener mOnEditorActionListener = new TextView.OnEditorActionListener() {
    
    
        @Override
        public boolean onEditorAction(TextView v, int actionId, KeyEvent event) {
    
    
            Log.d(TAG, "actionId: " + actionId);
            Log.d(TAG, "event:    " + event);
            return false;
        }
    };

If onEditorAction returns true, it means that this event is consumed.

The actionId above corresponds to android.view.inputmethod.EditorInfothe constant in .

public static final int IME_ACTION_UNSPECIFIED = 0x00000000;
public static final int IME_ACTION_NONE = 0x00000001;
public static final int IME_ACTION_GO = 0x00000002;
public static final int IME_ACTION_SEARCH = 0x00000003;
public static final int IME_ACTION_SEND = 0x00000004;
public static final int IME_ACTION_NEXT = 0x00000005;
public static final int IME_ACTION_DONE = 0x00000006;
public static final int IME_ACTION_PREVIOUS = 0x00000007;

EditText cursor movement and selection

Mainly introduces the setSelection method.

setSelection has:

setSelection(int start, int stop) selection range
setSelection(int index) moves the cursor to the specified position

Example: Assume there is EditText and the variable name is mEt1 .

Move the cursor to the front mEt1.setSelection(0);mEt1.setSelection(mEt1.getText().length());mEt1.setSelection(mEt1.getSelectionEnd() + 1);mEt1.setSelection(mEt1.getSelectionEnd() - 1); It should be noted that if the incoming index exceeds the range of text, a report will be reported. java.lang.IndexOutOfBoundsExceptionTherefore, in actual projects, it is necessary to determine whether the incoming position is within the length range of the existing content of EditText.
Move the cursor to the end
Move the cursor one position to the right
Move the cursor one position to the left
Select all currently input textmEt1.setSelection(0, mEt1.getText().length());

Monitor input content

Dynamically limit input length in code

Using TextWatcher

mQueryEt.addTextChangedListener(new TextWatcher() {
    
    
    @Override
    public void beforeTextChanged(CharSequence s, int start, int count, int after) {
    
    
    }

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

    }

    @Override
    public void afterTextChanged(Editable s) {
    
    
        // 如果EditText中的数据不为空，且长度大于指定的最大长度
        if (!TextUtils.isEmpty(s) && s.length() > 15) {
    
    
            // 删除指定长度之后的数据
            s.delete(15, s.length() - 1);
        }
    }
});

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