判断组件当前状态

footballboy

发布于 2021-4-13 10:45

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setComponentStateChangedListener方法判断组件当前状态

今天看到有坛友问到按钮点击调用setComponentStateChangedListener方法监控组件状态改变，触发了两次这个是正常吗？那接下来我来分享一下我的理解，有不对的请指出，谢谢！

首先我们先看布局页面，就是个简单的按钮，代码如下

<?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:orientation="vertical">

    <Button
        ohos:id="$+id:btnStateTest"
        ohos:height="match_content"
        ohos:width="match_content"
        ohos:text_size="30vp"
        ohos:background_element="gray"
        ohos:center_in_parent="true"
        ohos:text="测试按钮"
        ohos:bottom_margin="10vp"></Button>
</DirectionalLayout>

然后我们看Java代码如下

package com.example.phonetest.slice;

import com.example.phonetest.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.ComponentState;
import ohos.hiviewdfx.HiLog;
import ohos.hiviewdfx.HiLogLabel;

public class ButtonComponentStateTestSlice extends AbilitySlice {
    static final HiLogLabel label=new HiLogLabel(HiLog.LOG_APP,0x0001,"按钮状态测试");
    @Override
    public void onStart(Intent intent) {
        super.onStart(intent);
        super.setUIContent(ResourceTable.Layout_ability_button_component_state_test);
        Button btnStateTest=(Button)findComponentById(ResourceTable.Id_btnStateTest);
        HiLog.info(label,"按钮Id："+btnStateTest.getId());
        btnStateTest.setComponentStateChangedListener((c,i)->{
            HiLog.info(label,"组件Id："+c.getId());
            HiLog.info(label,"当前ViewState:"+i);

        });


    }

    @Override
    public void onActive() {
        super.onActive();
    }

    @Override
    public void onForeground(Intent intent) {
        super.onForeground(intent);
    }
}

然后我们看一下点击按钮打印的日志，如下图判断组件当前状态-鸿蒙开发者社区

为了验证是否都是同一个按钮测试的，我也将按钮的Id打出来了，我们可以看出事件方法里面触发的两次是同一个按钮，那么这两次状态改变是针对哪些状态呢，我找到ComponentState类的状态如下图，

判断组件当前状态-鸿蒙开发者社区

看了以后一脸蒙啊，完全对不上，这怎么搞，后来研究了半天，发现这个类里面还有个方法名叫isStateMatched，然后我想了一下是不是要用这个去匹配，然后我在setComponentStateChangedListener方法里面加入了如下测试代码

if(ComponentState.isStateMatched(ComponentState.COMPONENT_STATE_CHECKED,i)) {
    HiLog.info(label,"匹配ComponentState.COMPONENT_STATE_PRESSED");
    return;
}
if(ComponentState.isStateMatched(ComponentState.COMPONENT_STATE_DISABLED,i)) {
    HiLog.info(label,"匹配ComponentState.COMPONENT_STATE_DISABLED");
    return;
}
 if(ComponentState.isStateMatched(ComponentState.COMPONENT_STATE_EMPTY,i)) {
    HiLog.info(label,"匹配ComponentState.COMPONENT_STATE_EMPTY");
    return;
}
if(ComponentState.isStateMatched(ComponentState.COMPONENT_STATE_FOCUSED,i)) {
    HiLog.info(label,"匹配ComponentState.COMPONENT_STATE_FOCUSED");
    return;
}
if(ComponentState.isStateMatched(ComponentState.COMPONENT_STATE_HOVERED,i)) {
    HiLog.info(label,"匹配ComponentState.COMPONENT_STATE_HOVERED");
    return;
}
if(ComponentState.isStateMatched(ComponentState.COMPONENT_STATE_PRESSED,i)) {
    HiLog.info(label,"匹配ComponentState.COMPONENT_STATE_PRESSED");
    return;
}
if(ComponentState.isStateMatched(ComponentState.COMPONENT_STATE_SELECTED,i)) {
    HiLog.info(label,"匹配ComponentState.COMPONENT_STATE_PRESSED");
    return;
}
HiLog.info(label,"未匹配任何状态");

然后我再次单击测试按钮然后，我们看一下点击效果判断组件当前状态-鸿蒙开发者社区

然后得出的结论按钮为什么触发了两次，一次是按钮按下的状态，按下以后然后是恢复原来的未知状态。

接下来我又添加了几个按钮测试了一下手动禁用和手动按下状态，完全代码如下

<?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:orientation="vertical">

    <Button
        ohos:id="$+id:btnStateTest"
        ohos:height="match_content"
        ohos:width="match_content"
        ohos:text_size="30vp"
        ohos:background_element="gray"
        ohos:center_in_parent="true"
        ohos:text="测试按钮"
        ohos:bottom_margin="10vp"></Button>
    <Button
        ohos:id="$+id:btnStateDisabled"
        ohos:height="match_content"
        ohos:width="match_content"
        ohos:text_size="30vp"
        ohos:background_element="gray"
        ohos:center_in_parent="true"
        ohos:text="禁用测试按钮"
        ohos:bottom_margin="10vp"></Button>
    <Button
        ohos:id="$+id:btnStateEnable"
        ohos:height="match_content"
        ohos:width="match_content"
        ohos:text_size="30vp"
        ohos:background_element="gray"
        ohos:center_in_parent="true"
        ohos:text="启用测试按钮"
        ohos:bottom_margin="10vp"></Button>

    <Button
        ohos:id="$+id:btnStatePressed"
        ohos:height="match_content"
        ohos:width="match_content"
        ohos:text_size="30vp"
        ohos:background_element="gray"
        ohos:center_in_parent="true"
        ohos:text="手动设置测试按钮按下"
        ohos:bottom_margin="10vp"></Button>

    <Button
        ohos:id="$+id:btnStateCancelPressed"
        ohos:height="match_content"
        ohos:width="match_content"
        ohos:text_size="30vp"
        ohos:background_element="gray"
        ohos:center_in_parent="true"
        ohos:text="手动取消测试按钮按下"
        ohos:bottom_margin="10vp"></Button>

</DirectionalLayout>

Java代码如下

package com.example.phonetest.slice;

import com.example.phonetest.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.ComponentState;
import ohos.hiviewdfx.HiLog;
import ohos.hiviewdfx.HiLogLabel;

public class ButtonComponentStateTestSlice extends AbilitySlice {
    static final HiLogLabel label=new HiLogLabel(HiLog.LOG_APP,0x0001,"按钮状态测试");
    @Override
    public void onStart(Intent intent) {
        super.onStart(intent);
        super.setUIContent(ResourceTable.Layout_ability_button_component_state_test);
        Button btnStateTest=(Button)findComponentById(ResourceTable.Id_btnStateTest);
        HiLog.info(label,"按钮Id："+btnStateTest.getId());
        btnStateTest.setComponentStateChangedListener((c,i)->{
            HiLog.info(label,"组件Id："+c.getId());
            HiLog.info(label,"当前ViewState:"+i);
            if(ComponentState.isStateMatched(ComponentState.COMPONENT_STATE_CHECKED,i)) {
                HiLog.info(label,"匹配ComponentState.COMPONENT_STATE_PRESSED");
                return;
            }
            if(ComponentState.isStateMatched(ComponentState.COMPONENT_STATE_DISABLED,i)) {
                HiLog.info(label,"匹配ComponentState.COMPONENT_STATE_DISABLED");
                return;
            }
             if(ComponentState.isStateMatched(ComponentState.COMPONENT_STATE_EMPTY,i)) {
                HiLog.info(label,"匹配ComponentState.COMPONENT_STATE_EMPTY");
                return;
            }
            if(ComponentState.isStateMatched(ComponentState.COMPONENT_STATE_FOCUSED,i)) {
                HiLog.info(label,"匹配ComponentState.COMPONENT_STATE_FOCUSED");
                return;
            }
            if(ComponentState.isStateMatched(ComponentState.COMPONENT_STATE_HOVERED,i)) {
                HiLog.info(label,"匹配ComponentState.COMPONENT_STATE_HOVERED");
                return;
            }
            if(ComponentState.isStateMatched(ComponentState.COMPONENT_STATE_PRESSED,i)) {
                HiLog.info(label,"匹配ComponentState.COMPONENT_STATE_PRESSED");
                return;
            }
            if(ComponentState.isStateMatched(ComponentState.COMPONENT_STATE_SELECTED,i)) {
                HiLog.info(label,"匹配ComponentState.COMPONENT_STATE_PRESSED");
                return;
            }
            HiLog.info(label,"未匹配任何状态");
        });
        btnStateTest.setPressState(true);
        btnStateTest.setPressState(false);
        Button btnStateDisabled=(Button)findComponentById(ResourceTable.Id_btnStateDisabled);
        btnStateDisabled.setClickedListener(c->{
            HiLog.info(label,"禁用测试按钮");
            btnStateTest.setEnabled(false);
        });

        Button btnStateEnable=(Button)findComponentById(ResourceTable.Id_btnStateEnable);
        btnStateEnable.setClickedListener(c->{
            HiLog.info(label,"启用测试按钮");
            btnStateTest.setEnabled(true);
        });

        Button btnStatePressed=(Button)findComponentById(ResourceTable.Id_btnStatePressed);
        btnStatePressed.setClickedListener(c->{
            HiLog.info(label,"设置为pressState");
            btnStateTest.setPressState(true);
        });

        Button btnStateCancelPressed=(Button)findComponentById(ResourceTable.Id_btnStateCancelPressed);
        btnStateCancelPressed.setClickedListener(c->{
            HiLog.info(label,"取消pressState");
            btnStateTest.setPressState(false);
        });

    }

    @Override
    public void onActive() {
        super.onActive();
    }

    @Override
    public void onForeground(Intent intent) {
        super.onForeground(intent);
    }
}

然后在手动触发按下按钮，你又会发现一个有趣的现象就是直接在onStart方法里面调用setPressState方法和在按钮里面调用setPressState方法监控到状态码竟是不一样的，代码如下图判断组件当前状态-鸿蒙开发者社区