Svg not visible in device but visible in android xml

问题

I have used SVG's for these icons, the icons are visible in xml but not visible in device . following is my code :

                ` <LinearLayout
                    android:layout_width="match_parent"
                    android:layout_height="40dp"
                    android:layout_alignParentLeft="true"
                    android:layout_alignParentStart="true"
                    android:layout_alignParentTop="true"
                    android:gravity="center"
                    android:orientation="horizontal"
                    android:weightSum="10"
                   >

                    <ImageView
                        android:layout_width="0dp"
                        android:layout_height="25dp"
                        android:layout_weight="1.5"
                        app:srcCompat="@drawable/email_id_icon"
                        />

                    <EditText
                        android:layout_width="0dp"
                        android:id="@+id/et_email"
                        android:layout_height="wrap_content"
                        android:layout_weight="8"
                        android:textColor="#fff"
                        android:inputType="textEmailAddress"
                        android:background="@android:color/transparent"
                        android:hint="Email Id"
                        android:textColorHint="#fff"
                        android:imeOptions="actionNext"
                        />

                </LinearLayout>`

I have gone through similar questions on SO, most of them suggested to use android: src instead of app:srcCompat , but I have to use srcCompat only because of SVGs. So what should I do?

Edit - I have done the same thing in another activity's layout . here is the working code :

  <LinearLayout
        android:id="@+id/login_form_container"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_below="@id/textView2"
        android:gravity="center_horizontal"
        android:orientation="vertical"
        android:padding="20dp">

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="40dp"
            android:layout_alignParentLeft="true"
            android:layout_alignParentStart="true"
            android:layout_alignParentTop="true"
            android:gravity="center"
            android:orientation="horizontal"
            android:weightSum="10">

            <ImageView
                android:id="@+id/username_iv"
                android:layout_width="0dp"
                android:layout_height="25dp"


                android:layout_weight="2"
                app:srcCompat="@drawable/email_id_icon" />

            <EditText
                android:layout_width="0dp"
                android:id="@+id/username_et"
                android:layout_height="wrap_content"
                android:layout_weight="8"
                android:textColor="#fff"
                android:inputType="textEmailAddress"
                android:background="@android:color/transparent"
                android:hint="Email Id"
                android:textColorHint="#fff"
                android:imeOptions="actionNext"
                />

        </LinearLayout>

        <View
            android:layout_width="match_parent"
            android:layout_height="1dp"
            android:layout_marginBottom="10dp"
            android:background="#fff" />

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="40dp"
            android:layout_alignParentLeft="true"
            android:layout_alignParentStart="true"
            android:layout_alignParentTop="true"
            android:gravity="center"
            android:orientation="horizontal"
            android:weightSum="10">

            <ImageView
                android:id="@+id/password_iv"
                android:layout_width="0dp"
                android:layout_height="25dp"
                android:layout_weight="2"
                app:srcCompat="@drawable/password_icon" />

            <EditText
                android:id="@+id/password_et"
                android:layout_height="wrap_content"
                android:layout_weight="8"
                android:layout_width="0dp"
                android:background="@android:color/transparent"
                android:textColor="#fff"
                android:hint="Password"
                android:inputType="textPassword"
                android:fontFamily="roboto"
                android:textColorHint="#fff"
                 />

        </LinearLayout>

        <View
            android:layout_width="match_parent"
            android:layout_height="1dp"
            android:layout_marginBottom="20dp"
            android:background="#fff" />

        <Button
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:id="@+id/btn_login"
            android:layout_marginBottom="20dp"
            android:background="@drawable/login_button_style"
            android:text="Login"
            android:textSize="@dimen/headingText"
            android:textAllCaps="false"
            android:textColor="#fff" />

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/tv_forgetpassword"
            android:layout_marginBottom="10dp"
            android:text="Forget your password ?"
            android:textColor="#fff"
            android:textSize="@dimen/headingText" />


    </LinearLayout>

I did not want to have icons in 4 resolutions so I made a single .png image and converted into .svg using Android Studio's Vector asset .

回答1:

Make sure you are using AppCompatActivity and not Activity. If you are using Activity, then write in your activity / fragment:

imageView.setImageResource(R.drawable.ic_svg_image);

Also add in build.gradle:

android {  
    defaultConfig {  
        vectorDrawables.useSupportLibrary = true  
    }  
}

And for 4.x versions of Android you can also add a support for TextViews' inner drawables. This is also actual for ImageViews.

public class MyApplication extends Application {
    @Override
    public void onCreate() {
        super.onCreate();
        // This flag should be set to true to enable VectorDrawable support for API < 21.
        AppCompatDelegate.setCompatVectorFromResourcesEnabled(true);
    }
}

Then in AndroidManifest add this file:

<application
    android:name=".MyApplication"
    android:icon="@mipmap/ic_launcher"
    android:label="@string/app_name"
    android:roundIcon="@mipmap/ic_launcher_round"
    android:supportsRtl="true"
    android:theme="@style/AppTheme">
    ...
</application>

Sometimes it crushes on some old devices. Then wrap your drawable inside:

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:drawable="@drawable/ic_svg_image/>
</selector>

and set it instead of SVG:

<ImageView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    app:srcCompat="@drawable/drawable"
    />

回答2:

you can use VectorDrawable

Here is a tool to convert you svg to VectorDrawable

On pre lollipop device svg support is not quite comprehensive.

Add this in your build.gradle

 android {  
    defaultConfig {  
        vectorDrawables.useSupportLibrary = true  
    }  
}  

来源：https://stackoverflow.com/questions/43594751/svg-not-visible-in-device-but-visible-in-android-xml