package com.example.handwriting import android.os.Bundle import androidx.activity.ComponentActivity import androidx.activity.compose.setContent import androidx.compose.foundation.layout.fillMaxSize import androidx.compose.material3.MaterialTheme import androidx.compose.material3.Surface import androidx.compose.material3.Text import androidx.compose.runtime.Composable import androidx.compose.ui.Modifier import androidx.compose.ui.tooling.preview.Preview import com.example.handwriting.ui.theme.HandWritingTheme class MainActivity : ComponentActivity() { override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContent { HandWritingTheme { // A surface container using the 'background' color from the theme Surface( modifier = Modifier.fillMaxSize(), color = MaterialTheme.colorScheme.background ) { Greeting("Android") } } } } } @Composable fun Greeting(name: String, modifier: Modifier = Modifier) { Text( text = "Hello $name!", modifier = modifier ) } @Preview(showBackground = true) @Composable fun GreetingPreview() { HandWritingTheme { Greeting("Android") } }请加 button click 事件 ，启动新activity

好的，我可以帮您在这段代码中添加button click事件，启动新的activity。请参考下面的代码：

package com.example.handwriting

import android.content.Intent
import android.os.Bundle
import androidx.activity.ComponentActivity
import androidx.activity.compose.setContent
import androidx.compose.foundation.layout.fillMaxSize
import androidx.compose.material3.Button
import androidx.compose.material3.MaterialTheme
import androidx.compose.material3.Surface
import androidx.compose.material3.Text
import androidx.compose.runtime.Composable
import androidx.compose.ui.Modifier
import androidx.compose.ui.tooling.preview.Preview
import com.example.handwriting.ui.theme.HandWritingTheme

class MainActivity : ComponentActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContent {
            HandWritingTheme {
                // A surface container using the 'background' color from the theme
                Surface(
                    modifier = Modifier.fillMaxSize(),
                    color = MaterialTheme.colorScheme.background
                ) {
                    Greeting("Android")
                    LaunchNewActivityButton()
                }
            }
        }
    }
}

@Composable
fun Greeting(name: String, modifier: Modifier = Modifier) {
    Text(
        text = "Hello $name!",
        modifier = modifier
    )
}

@Composable
fun LaunchNewActivityButton() {
    Button(
        onClick = {
            val intent = Intent(
                LocalContext.current,
                NewActivity::class.java
            )
            startActivity(intent)
        },
        modifier = Modifier.padding(top = 16.dp)
    ) {
        Text("Launch New Activity")
    }
}

@Preview(showBackground = true)
@Composable
fun GreetingPreview() {
    HandWritingTheme {
        Greeting("Android")
    }
}

在这个代码中，我们首先在onCreate()方法中添加了一个新的组件LaunchNewActivityButton()，它是在Material Design组件库中的Button组件的基础上实现的。在这个组件中，我们创建了一个新的Intent对象，指定了当前activity为MainActivity，目标activity为NewActivity，并启动了这个新的activity。您可以根据实际情况，修改NewActivity为您需要启动的目标activity的名称。