How to Set Maximum Input Length in TextField in Android using Jetpack Compose?
In Android, EditText is used to collect text-based user input inside the activity on the screen. Similarly, in Jetpack Compose, a TextField element is used to collect input text on the activity screen. By default, there is no limit to what users can type inside the TextField.
So in this article, we will show you how you could Set Maximum Input Length in TextField in Android using Jetpack Compose. Follow the below steps once the IDE is ready.
Step by Step Implementation
Step 1: Create a New Project in Android Studio
To create a new project in Android Studio please refer to How to Create/Start a New Project in Android Studio. While choosing the template, select Empty Compose Activity. If you do not find this template, try upgrading the Android Studio to the latest version. We demonstrated the application in Kotlin, so make sure you select Kotlin as the primary language while creating a New Project.
Step 2: Working with the MainActivity.kt file
Go to the MainActivity.kt file and refer to the following code. Below is the code for the MainActivity.kt file. Comments are added inside the code to understand the code in more detail.
Kotlin
package com.w3wiki.jctextfieldmaxlength import android.os.Bundle import android.widget.Toast import androidx.activity.ComponentActivity import androidx.activity.compose.setContent import androidx.compose.foundation.layout.Arrangement import androidx.compose.foundation.layout.Column import androidx.compose.foundation.layout.fillMaxSize import androidx.compose.material.* import androidx.compose.runtime.* import androidx.compose.ui.Alignment import androidx.compose.ui.Modifier import androidx.compose.ui.graphics.Color import androidx.compose.ui.platform.LocalContext import androidx.compose.ui.text.input.TextFieldValue import androidx.compose.ui.tooling.preview.Preview import com.w3wiki.jctextfieldmaxlength.ui.theme.JCTextFieldMaxLengthTheme class MainActivity : ComponentActivity() { override fun onCreate(savedInstanceState: Bundle?) { super .onCreate(savedInstanceState) setContent { // Calling the composable function // to display element and its contents MainContent() } } } // Creating a composable // function to display Top Bar @Composable fun MainContent() { Scaffold( topBar = { TopAppBar(title = { Text( "GFG | TextField Max Length" , color = Color.White) }, backgroundColor = Color( 0xff0f9d58 )) }, content = { MyContent() } ) } // Creating a composable function // to create a TextField // Calling this function as content // in the above function @Composable fun MyContent(){ // creating a string variable // to store TextField value var mText by remember { mutableStateOf(TextFieldValue( "" )) } // creating a variable of value 5 val mMaxLength = 5 // fetching local context val mContext = LocalContext.current Column(Modifier.fillMaxSize(), horizontalAlignment = Alignment.CenterHorizontally, verticalArrangement = Arrangement.Center) { // Creating a text field and adding a // condition to limit the input to 5 chars. TextField( singleLine = true , value = mText, onValueChange = { if (it.text.length <= mMaxLength) mText = it else Toast.makeText(mContext, "Cannot be more than 5 Characters" , Toast.LENGTH_SHORT).show() } ) } } // For displaying preview in // the Android Studio IDE emulator @Preview (showBackground = true ) @Composable fun DefaultPreview() { MainContent() } |
Output:
You can see that the TextField input is now limited to 5 characters.