为什么我看不到 cardView 的内容？

Question

我有一个cardView，但是看不到内容。我分享了部分代码，希望能得到帮助。谢谢你。我的项目直接在我的单元格phone上执行。并且只显示 cardView 但没有内容。

card_view.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
xmlns:card_view="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="wrap_content">

<android.support.v7.widget.CardView
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:card_view="http://schemas.android.com/apk/res-auto"
    android:id="@+id/card_view_v"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_margin="5dp"

    app:cardBackgroundColor="@android:color/white"
    app:cardCornerRadius="2dp"
    app:cardElevation="2dp">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical">
        <ImageView
            android:layout_width="match_parent"
            android:layout_height="200dp"


            tools:src="@drawable/pika"/>
        <TextView
            android:id="@+id/text"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:background="?android:selectableItemBackground"
            android:padding="20dp"
            tools:text="Paris"
            android:fontFamily="sans-serif"
            android:textColor="#333"
            android:textSize="18sp"/>
    </LinearLayout>



</android.support.v7.widget.CardView>

build.gradle

apply plugin: 'com.android.application'
android {
compileSdkVersion 25
buildToolsVersion "25.0.2"
defaultConfig {
    applicationId "com.example.ivann.cardview"
    minSdkVersion 15
    targetSdkVersion 25
    versionCode 1
    versionName "1.0"
    testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
}
buildTypes {
    release {
        minifyEnabled false
        proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
    }
}

}

dependencies {
compile fileTree(dir: 'libs', include: ['*.jar'])
androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
    exclude group: 'com.android.support', module: 'support-annotations'
})
compile 'com.android.support:appcompat-v7:25.2.0'
compile 'com.android.support:cardview-v7:25.0.0'
testCompile 'junit:junit:4.12'

}

Answer 1

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    xmlns:card_view="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="wrap_content">

    <android.support.v7.widget.CardView
        xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:tools="http://schemas.android.com/tools"
        xmlns:app="http://schemas.android.com/apk/res-auto"
        xmlns:card_view="http://schemas.android.com/apk/res-auto"
        android:id="@+id/card_view_v"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_margin="5dp"

        app:cardBackgroundColor="@android:color/white"
        app:cardCornerRadius="2dp"
        app:cardElevation="2dp">

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="vertical">
            <ImageView
                android:layout_width="match_parent"
                android:layout_height="200dp"
                android:src="@drawable/pika"
                />

            <TextView
                android:id="@+id/text"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:background="?android:selectableItemBackground"
                android:padding="20dp"
                tools:text="Paris"
                android:fontFamily="sans-serif"
                android:textColor="#333"
                android:textSize="18sp"/>
        </LinearLayout>



    </android.support.v7.widget.CardView>
</LinearLayout>

您没有在最后关闭线性布局标签

Answer 2

只需尝试为 imageView 和 textView 提供 android:src 而不是 tool:src

可能有用！

为什么我看不到 cardView 的内容？

Why do not I see the contents of my cardView?

android

gradle

android-studio

android-gradle-plugin

android-cardview