React Native TextInput not scroll in ScrollView

I write a code like this:

<View style={{flex:1}}>
    <ScrollView style={{flex:1, backgroundColor='#ffffff'}}>
        <TextInput style={styles.inputText} 
                   value={this.state.mail}
                   placeholder="Email"
                   onChangeText={(text)=>this.setState.(mail:text)}/>
        <TextInput style={styles.inputText} 
                   value={this.state.fName}
                   placeholder="First name"
                   onChangeText={(text)=>this.setState.(fName:text)}/>
        <TextInput style={styles.inputText} 
                   value={this.state.sName}
                   placeholder="Second name"
                   onChangeText={(text)=>this.setState.(sName:text)}/>
    </ScrollView>
</View>

but when i drag start in TextInput does not scroll! i drag like this picture: enter image description here but not scroll…

Answer

Problem solved. I just add this props to TextInput Components:

multiline={true}
numberOfLines={1}