android 解决selector失效问题

偏执的太偏执、 2024-04-17 06:18 63阅读 0赞

android里面 selector用于按钮的背景状态切换，很多年前似乎也遇到过这个失效的坑，当时没记录，百度半天也没找到解决答案，最后弄了很久找到了问题所在，这里记录下，防止下次再踩坑。

先贴失效的xml

<?xml version="1.0" encoding="utf-8"?>
    <selector xmlns:android="http://schemas.android.com/apk/res/android">
    
        <item>
            <shape>
                <solid android:color="@color/white" />
                <corners android:radius="4dp" />
                <stroke android:width="@dimen/dimen_1"
                    android:color="@color/blue1286F1"/>
            </shape>
        </item>
        
        <item android:state_selected="true">
            <shape>
                <solid android:color="@color/blue1286F1" />
                <corners android:radius="4dp" />
            </shape>
        </item>
    
        <item android:state_checked="true">
            <shape>
                <solid android:color="@color/blue1286F1" />
                <corners android:radius="4dp" />
            </shape>
        </item>
    
    </selector>

再贴正常的xml

<?xml version="1.0" encoding="utf-8"?>
    <selector xmlns:android="http://schemas.android.com/apk/res/android">
    
        <item android:state_selected="true">
            <shape>
                <solid android:color="@color/blue1286F1" />
                <corners android:radius="4dp" />
            </shape>
        </item>
    
        <item android:state_checked="true">
            <shape>
                <solid android:color="@color/blue1286F1" />
                <corners android:radius="4dp" />
            </shape>
        </item>
    
        <item>
            <shape>
                <solid android:color="@color/white" />
                <corners android:radius="4dp" />
                <stroke android:width="@dimen/dimen_1"
                    android:color="@color/blue1286F1"/>
            </shape>
        </item>
    </selector>

晃眼一看，这不就是一样的吗？其实是有差异的，默认状态那个Item必须放在最底部，否则失效，为啥呢？I don't know!