输入时清除 EditText 中的文本

First you need to call setContentView(R.layout.main) then all other initialization.

Please try below Code.

public class Trackfolio extends Activity implements OnClickListener {
/** Called when the activity is first created. */
public EditText editText;


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


setContentView(R.layout.main);


editText = (EditText) findViewById(R.id.editText1);
editText.setOnClickListener(this);
}


@Override
public void onClick(View v) {
editText.getText().clear(); //or you can use editText.setText("");
}
}

Your code should be:

    public class Project extends Activity implements OnClickListener {
/** Called when the activity is first created. */
EditText editText;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);


setContentView(R.layout.main);
editText = (EditText)findViewById(R.id.editText1);
editText.setOnClickListener(this);
}


@Override
public void onClick(View v) {
// TODO Auto-generated method stub


if(v == editText) {
editText.setText("");
}
}
}

public EditText editField;
public Button clear = null;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.text_layout);
this. editField = (EditText)findViewById(R.id.userName);
this.clear = (Button) findViewById(R.id.clear_button);
this.editField.setOnClickListener(this);
this.clear.setOnClickListener(this);
@Override
public void onClick(View v) {


// TODO Auto-generated method stub
if(v.getId()==R.id.clear_button){
//setText will remove all text that is written by someone
editField.setText("");
}
}

i don't know what mistakes i did while implementing the above solutions, bt they were unsuccessful for me

txtDeck.setOnFocusChangeListener(new OnFocusChangeListener() {
@Override
public void onFocusChange(View v, boolean hasFocus) {
txtDeck.setText("");
}
});

This works for me,

Also you can use code below

editText.getText().clear();

//To clear When Clear Button is Clicked

firstName = (EditText) findViewById(R.id.firstName);

    clear = (Button) findViewById(R.id.clearsearchSubmit);


clear.setOnClickListener(new OnClickListener() {


@Override
public void onClick(View v) {
// TODO Auto-generated method stub
if (v.getId() == R.id.clearsearchSubmit);
firstName.setText("");
}
});

This will help to clear the wrong keywords that you have typed in so instead of pressing backspace again and again you can simply click the button to clear everything.It Worked For me. Hope It Helps

just use the android:hint attribute in your EditText. This text shows up when the box is empty and not focused, but disappears upon selecting the EditText box.

package com.example.sampleproject;


import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ImageView;


public class SampleProject extends Activity {
EditText mSearchpeople;
Button mCancel , msearchclose;
ImageView mprofile, mContact, mcalender, mConnection, mGroup , mFollowup , msetting , mAddacard;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.dashboard);
mSearchpeople = (EditText)findViewById(R.id.editText1);
mCancel = (Button)findViewById(R.id.button2);
msearchclose = (Button)findViewById(R.id.button1);
mprofile = (ImageView)findViewById(R.id.imageView1);
mContact = (ImageView)findViewById(R.id.imageView2);
mcalender = (ImageView)findViewById(R.id.imageView3);
mConnection = (ImageView)findViewById(R.id.imageView4);
mGroup = (ImageView)findViewById(R.id.imageView5);
mFollowup = (ImageView)findViewById(R.id.imageView6);
msetting = (ImageView)findViewById(R.id.imageView7);
mAddacard = (ImageView)findViewById(R.id.imageView8);
}
@Override
protected void onResume() {
// TODO Auto-generated method stub
super.onResume();
mCancel.setOnClickListener(new View.OnClickListener() {


@Override
public void onClick(View v) {
// TODO Auto-generated method stub
mSearchpeople.clearFocus();


}
});
}




}

Very Simple to clear editText values.when u click button then only follow 1 line code.

Inside button or anywhere u want.Only use this

editText.setText("");

final EditText childItem = (EditText) convertView.findViewById(R.id.child_item);
childItem.setHint(cellData);


childItem.setOnFocusChangeListener(new View.OnFocusChangeListener() {
@Override
public void onFocusChange(View v, boolean hasFocus) {
//Log.d("NNN", "Has focus " + hasFocus);
if (hasFocus) {
Toast.makeText(ctx.getApplicationContext(), "got the focus", Toast.LENGTH_LONG).show();
} else {
Toast.makeText(ctx.getApplicationContext(),
"loss the focus", Toast.LENGTH_SHORT).show();
}
return;
});

by setting Empty string you can clear your edittext

    editext.setText("");

We can clear EditText data in two ways

First One setting EditText is empty like below line

editext.setText("");

Second one clearing EditText data like this

editText.getText().clear();

I suggest second way

You can use the 'android:hint' attribute in your EditText also from code:

editText.setHint(CharSequence hint / int resid);

Then you don't need any onClickListener or similar. But consider that the hint value won't be passed. The editText will be stayed empty. In this case you can set your editText with your deflault value:

if(editText.getText().toString().equals("")) {
...use your default value instead of the editText... }

If the use of EditText is not mandatory, you can implement this behavior easily with the new material components:

<com.google.android.material.textfield.TextInputLayout
style="@style/Widget.MaterialComponents.TextInputLayout.OutlinedBox.Dense"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="@string/hint_field"
app:endIconDrawable="@drawable/ic_close_black_24dp"
app:endIconMode="clear_text"
app:endIconTint="@color/black">


<com.google.android.material.textfield.TextInputEditText
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="@string/hint_value"
android:maxLines="1"
android:text="@{itemModel.value}" />


</com.google.android.material.textfield.TextInputLayout>

You only have to specify the drawable you want for the button that will clear the text and the action that it will execute. To clear the text, you can use iconMode="clear_text", but also "password_toggle" is available.

In XML you can write like:

    <EditText
android:id="@+id/txtsearch"
android:layout_width="250dp"
android:layout_height="match_parent"
android:layout_gravity="right"
android:layout_weight="1"
android:background="@drawable/roundlayoutbutton1"
android:ems="10"
android:gravity="center"
android:inputType="text"
android:textAllCaps="true"
android:text="search_xxxx"


android:textColor="@color/colorPrimaryDark"
android:visibility="visible" />

and in java class you may have below one :

    EditText searchHost;

OnCreate() you write:

    searchHost=findViewById(R.id.txtsearch);


searchHost.setOnFocusChangeListener(new View.OnFocusChangeListener() {
@Override
public void onFocusChange(View v, boolean hasFocus) {
if(searchHost.getText().toString().equalsIgnoreCase("search_xxxx")){
searchHost.setText("");
Toast.makeText(getApplicationContext(),"Enter you text xxx...", Toast.LENGTH_LONG).show();
}
}
});

It works fine for me.

It's simple: declare the widget variables (editText, textView, button etc.) in class but initialize it in onCreate after setContentView.

The problem is when you try to access a widget of a layout first you have to declare the layout. Declaring the layout is setContentView. And when you initialize the widget variable via findViewById you are accessing the id of the widget in the main layout in the setContentView.

I hope you get it!

For Kotlin:

Create two extensions, one for EditText and one for TextView

EditText:

fun EditText.clear() { text.clear() }

TextView:

fun TextView.clear() { text = "" }

and use it like

myEditText.clear()


myTextView.clear()

I am not sure if your searching for this one

    {
<EditText
.
.
android:hint="Please enter your name here">
}