1. 长按事件
- 长按事件使用的次数不是很多,但在有些特殊的情况下还是要用到的。
- 比如:复制一段文字的时候就是长按操作
- 长按事件和单、双击事件也非常类似
- 接口名:
LongClickedListener
2. 实现案例:长按按钮修改文本内容
- 新建项目:ListenerApplication3
ability_main
<?xml version="1.0" encoding="utf-8"?>
<DirectionalLayout
xmlns:ohos="http://schemas.huawei.com/res/ohos"
ohos:height="match_parent"
ohos:width="match_parent"
ohos:alignment="center"
ohos:orientation="vertical">
<Text
ohos:id="$+id:text1"
ohos:height="match_content"
ohos:width="match_content"
ohos:text="text"
ohos:text_size="100">
</Text>
<Button
ohos:id="$+id:but1"
ohos:height="match_content"
ohos:width="match_content"
ohos:text="点我"
ohos:text_size="100"
ohos:background_element="red">
</Button>
</DirectionalLayout>
MainAbilitySlice
package com.xdr630.listenerapplication3.slice;
import com.xdr630.listenerapplication3.ResourceTable;
import ohos.aafwk.ability.AbilitySlice;
import ohos.aafwk.content.Intent;
import ohos.agp.components.Button;
import ohos.agp.components.Component;
import ohos.agp.components.Text;
public class MainAbilitySlice extends AbilitySlice implements Component.LongClickedListener {
//提为成员变量,否则onLongClicked访问不到文本组件,并初始化默认值
Text text1 = null;
@Override
public void onStart(Intent intent) {
super.onStart(intent);
super.setUIContent(ResourceTable.Layout_ability_main);
//1.找到文本框组件和按钮组件
text1 = (Text) findComponentById(ResourceTable.Id_text1);
Button but1 = (Button) findComponentById(ResourceTable.Id_but1);
//2.绑定长按事件,点谁就给谁绑定事件
//当对按钮进行长按操作时,就会执行this本类中onLongClicked方法
but1.setLongClickedListener(this);
}
@Override
public void onActive() {
super.onActive();
}
@Override
public void onForeground(Intent intent) {
super.onForeground(intent);
}
@Override
public void onLongClicked(Component component) {
//修改文本框的内容
text1.setText("长按");
}
}
- 运行:
- 长按按钮后: