Android - Gridlayout android.support.v7.widget.GridLayout cannot be cast to android.widget.GridLayout

Question

I want to create a GridLayout able to run in all the APIs.

The thing is, when i use GridLayout instead of android.support.v7.widget.GridLayout the app runs fine in Android 7.1.1 but in older versions it crashes.

But if i use android.support.v7.widget.GridLayout instead of GridLayout (like the code below) it always crashes.

activity_main

<?xml version="1.0" encoding="utf-8"?>
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:background="#FFF"
    tools:context="devector.dom.gridtest.MainActivity">


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



    <RelativeLayout

        android:layout_width="match_parent"
        android:layout_height="wrap_content">

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/textGrid"
            android:text="Grid test"
            android:textColor="#000"
            android:layout_centerInParent="true"
            android:textSize="34sp"
            />
    </RelativeLayout>

    <android.support.v7.widget.GridLayout
        android:textAlignment="center"
        android:id="@+id/mainGrid"
        android:padding="25dp"
        android:layout_marginLeft="8dp"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        app:columnCount="2"
        app:rowCount="3"
        app:alignmentMode="alignMargins"
        app:columnOrderPreserved="false">


        <!-- Row 1 -->
        <!-- Column 1-->

        <android.support.v7.widget.CardView
            android:layout_width="150dp"
            android:layout_height="125dp"
            android:layout_marginBottom="16dp"
            android:layout_marginLeft="16dp"
            android:layout_marginRight="16dp"
            app:cardElevation="8dp"
            app:cardCornerRadius="8dp"
            >


            <LinearLayout
                android:layout_gravity="center_horizontal|center_vertical"
                android:layout_margin="16dp"
                android:orientation="vertical"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                >

                <ImageView
                    android:src="@drawable/zerotwo"
                    android:layout_gravity="center_horizontal"
                    android:layout_width="70dp"
                    android:layout_height="70dp"
                    />

                <TextView
                    android:text="Zero"
                    android:textAlignment="center"
                    android:textColor="#000"
                    android:textSize="18sp"
                    android:textStyle="bold"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content" />
            </LinearLayout>

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

        <!-- Row 2 -->
        <!-- Column 2-->

        <android.support.v7.widget.CardView
            android:layout_width="150dp"
            android:layout_height="125dp"
            android:layout_marginBottom="16dp"
            android:layout_marginLeft="16dp"
            android:layout_marginRight="16dp"
            app:cardElevation="8dp"
            app:cardCornerRadius="8dp"
            >


            <LinearLayout
                android:layout_gravity="center_horizontal|center_vertical"
                android:layout_margin="16dp"
                android:orientation="vertical"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                >

                <ImageView
                    android:src="@drawable/zerotwo"
                    android:layout_gravity="center_horizontal"
                    android:layout_width="70dp"
                    android:layout_height="70dp"
                    />

                <TextView
                    android:text="Two"
                    android:textAlignment="center"
                    android:textColor="#000"
                    android:textSize="18sp"
                    android:textStyle="bold"

                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content" />
            </LinearLayout>

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

        <!-- Row 3-->
        <!-- Column 3-->

        <android.support.v7.widget.CardView
            android:layout_width="150dp"
            android:layout_height="125dp"
            android:layout_marginBottom="16dp"
            android:layout_marginLeft="16dp"
            android:layout_marginRight="16dp"
            app:cardElevation="8dp"
            app:cardCornerRadius="8dp"
            >


            <LinearLayout
                android:layout_gravity="center_horizontal|center_vertical"
                android:layout_margin="16dp"
                android:orientation="vertical"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                >

                <ImageView
                    android:src="@drawable/zerotwo"
                    android:layout_gravity="center_horizontal"
                    android:layout_width="70dp"
                    android:layout_height="70dp"
                    />

                <TextView
                    android:text="Is"
                    android:textAlignment="center"
                    android:textColor="#000"
                    android:textSize="18sp"
                    android:textStyle="bold"

                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content" />
            </LinearLayout>

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

        <!-- Row 4 -->
        <!-- Column 4-->

        <android.support.v7.widget.CardView
            android:layout_width="150dp"
            android:layout_height="125dp"
            android:layout_marginBottom="16dp"
            android:layout_marginLeft="16dp"
            android:layout_marginRight="16dp"
            app:cardElevation="8dp"
            app:cardCornerRadius="8dp"
            >


            <LinearLayout
                android:layout_gravity="center_horizontal|center_vertical"
                android:layout_margin="16dp"
                android:orientation="vertical"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                >

                <ImageView
                    android:src="@drawable/zerotwo"
                    android:layout_gravity="center_horizontal"
                    android:layout_width="70dp"
                    android:layout_height="70dp"
                    />

                <TextView
                    android:text="The"
                    android:textAlignment="center"
                    android:textColor="#000"
                    android:textSize="18sp"
                    android:textStyle="bold"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content" />
            </LinearLayout>

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

        <!-- Row 5 -->
        <!-- Column 5-->

        <android.support.v7.widget.CardView
            android:layout_width="150dp"
            android:layout_height="125dp"
            android:layout_marginBottom="16dp"
            android:layout_marginLeft="16dp"
            android:layout_marginRight="16dp"
            app:cardElevation="8dp"
            app:cardCornerRadius="8dp"
            >


            <LinearLayout
                android:layout_gravity="center_horizontal|center_vertical"
                android:layout_margin="16dp"
                android:orientation="vertical"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                >

                <ImageView
                    android:src="@drawable/zerotwo"
                    android:layout_gravity="center_horizontal"
                    android:layout_width="70dp"
                    android:layout_height="70dp"
                    />

                <TextView
                    android:text="Besto"
                    android:textAlignment="center"
                    android:textColor="#000"
                    android:textSize="18sp"
                    android:textStyle="bold"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content" />
            </LinearLayout>

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

        <!-- Row 6 -->
        <!-- Column 6-->

        <android.support.v7.widget.CardView
            android:layout_width="150dp"
            android:layout_height="125dp"
            android:layout_marginBottom="16dp"
            android:layout_marginLeft="16dp"
            android:layout_marginRight="16dp"
            app:cardElevation="8dp"
            app:cardCornerRadius="8dp"
            >


            <LinearLayout
                android:layout_gravity="center_horizontal|center_vertical"
                android:layout_margin="16dp"
                android:orientation="vertical"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                >

                <ImageView
                    android:src="@drawable/zerotwo"
                    android:layout_gravity="center_horizontal"
                    android:layout_width="70dp"
                    android:layout_height="70dp"
                    />

                <TextView
                    android:text="Waifu"
                    android:textAlignment="center"
                    android:textColor="#000"
                    android:textSize="18sp"
                    android:textStyle="bold"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content" />
            </LinearLayout>

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

        <!-- Row 7 -->
        <!-- Column 7-->

        <android.support.v7.widget.CardView
            android:layout_width="150dp"
            android:layout_height="125dp"
            android:layout_marginBottom="16dp"
            android:layout_marginLeft="16dp"
            android:layout_marginRight="16dp"
            app:cardElevation="8dp"
            app:cardCornerRadius="8dp"
            >


            <LinearLayout
                android:layout_gravity="center_horizontal|center_vertical"
                android:layout_margin="16dp"
                android:orientation="vertical"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                >

                <ImageView
                    android:src="@drawable/zerotwo"
                    android:layout_gravity="center_horizontal"
                    android:layout_width="70dp"
                    android:layout_height="70dp"
                    />

                <TextView
                    android:text="Never"
                    android:textAlignment="center"
                    android:textColor="#000"
                    android:textSize="18sp"
                    android:textStyle="bold"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content" />
            </LinearLayout>

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

        <!-- Row 8 -->
        <!-- Column 8-->

        <android.support.v7.widget.CardView
            android:layout_width="150dp"
            android:layout_height="125dp"
            android:layout_marginBottom="16dp"
            android:layout_marginLeft="16dp"
            android:layout_marginRight="16dp"
            app:cardElevation="8dp"
            app:cardCornerRadius="8dp"
            >


            <LinearLayout
                android:layout_gravity="center_horizontal|center_vertical"
                android:layout_margin="16dp"
                android:orientation="vertical"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                >

                <ImageView
                    android:src="@drawable/zerotwo"
                    android:layout_gravity="center_horizontal"
                    android:layout_width="70dp"
                    android:layout_height="70dp"
                    />

                <TextView
                    android:text="Forget"
                    android:textAlignment="center"
                    android:textColor="#000"
                    android:textSize="18sp"
                    android:textStyle="bold"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content" />
            </LinearLayout>

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

        <!-- Row 9 -->
        <!-- Column 9-->

        <android.support.v7.widget.CardView
            android:layout_width="150dp"
            android:layout_height="125dp"
            android:layout_marginBottom="16dp"
            android:layout_marginLeft="16dp"
            android:layout_marginRight="16dp"
            app:cardElevation="8dp"
            app:cardCornerRadius="8dp"
            >


            <LinearLayout
                android:layout_gravity="center_horizontal|center_vertical"
                android:layout_margin="16dp"
                android:orientation="vertical"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                >

                <ImageView
                    android:src="@drawable/zerotwo"
                    android:layout_gravity="center_horizontal"
                    android:layout_width="70dp"
                    android:layout_height="70dp"
                    />

                <TextView
                    android:text="About"
                    android:textAlignment="center"
                    android:textColor="#000"
                    android:textSize="18sp"
                    android:textStyle="bold"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content" />
            </LinearLayout>

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

        <!-- Row 10 -->
        <!-- Column 10-->

        <android.support.v7.widget.CardView
            android:layout_width="150dp"
            android:layout_height="125dp"
            android:layout_marginBottom="16dp"
            android:layout_marginLeft="16dp"
            android:layout_marginRight="16dp"
            app:cardElevation="8dp"
            app:cardCornerRadius="8dp"
            >


            <LinearLayout
                android:layout_gravity="center_horizontal|center_vertical"
                android:layout_margin="16dp"
                android:orientation="vertical"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                >

                <ImageView
                    android:src="@drawable/zerotwo"
                    android:layout_gravity="center_horizontal"
                    android:layout_width="70dp"
                    android:layout_height="70dp"
                    />

                <TextView
                    android:text="It"
                    android:textAlignment="center"
                    android:textColor="#000"
                    android:textSize="18sp"
                    android:textStyle="bold"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content" />
            </LinearLayout>

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

</ScrollView>

Logs

FATAL EXCEPTION: main
Process: devector.dom.gridtest, PID: 15773
java.lang.RuntimeException: Unable to start activity ComponentInfo{devector.dom.gridtest/devector.dom.gridtest.MainActivity}: java.lang.ClassCastException: android.support.v7.widget.GridLayout cannot be cast to android.widget.GridLayout
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2678)
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2743)
    at android.app.ActivityThread.-wrap12(ActivityThread.java)
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1490)
    at android.os.Handler.dispatchMessage(Handler.java:102)
    at android.os.Looper.loop(Looper.java:154)
    at android.app.ActivityThread.main(ActivityThread.java:6165)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:888)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:778)
Caused by: java.lang.ClassCastException: android.support.v7.widget.GridLayout cannot be cast to android.widget.GridLayout
    at devector.dom.gridtest.MainActivity.onCreate(MainActivity.java:21)
    at android.app.Activity.performCreate(Activity.java:6687)
    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1140)
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2631)
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2743) 
    at android.app.ActivityThread.-wrap12(ActivityThread.java) 
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1490) 
    at android.os.Handler.dispatchMessage(Handler.java:102) 
    at android.os.Looper.loop(Looper.java:154) 
    at android.app.ActivityThread.main(ActivityThread.java:6165) 
    at java.lang.reflect.Method.invoke(Native Method) 
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:888) 
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:778) 

Gradle

apply plugin: 'com.android.application'

android {
    compileSdkVersion 26
    defaultConfig {
        applicationId "devector.dom.gridtest"
        minSdkVersion 15
        targetSdkVersion 26
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}


dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])
    implementation 'com.android.support:appcompat-v7:26.1.0'
    implementation 'com.android.support:cardview-v7:26.1.0'
    implementation 'com.android.support.constraint:constraint-layout:1.0.2'
    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'com.android.support.test:runner:1.0.1'
    androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.1'
    implementation 'com.android.support:gridlayout-v7:26.1.0'
    implementation 'com.android.support:design:26.1.0'

}

MainActivity.java

package devector.dom.gridtest;

import android.content.Intent;
import android.graphics.Color;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.CardView;
import android.view.View;
import android.widget.GridLayout;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {

    GridLayout mainGrid;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        mainGrid = (GridLayout) findViewById(R.id.mainGrid);


        setSingleEvent(mainGrid);
    }


    private void setSingleEvent(GridLayout mainGrid) {

        for (int i = 0; i < mainGrid.getChildCount(); i++) {
            CardView cardView = (CardView) mainGrid.getChildAt(i);
            final int finalI = i;
            cardView.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View view) {

                  if(finalI == 0) 
                  {
                      Intent intent = new Intent(MainActivity.this,Activity_one.class );
                      startActivity(intent);
                  } 

                }
            });
        }
    }
}

Answer 1

import androidx.gridlayout.widget.GridLayout

Do this in you MainActiviy sheet.

You should edit the import.android.widget.GridLayout

as

import androidx.gridlayout.widget.GridLayout

Answer 2

Replace

import android.widget.GridLayout;

with

import android.support.v7.widget.GridLayout;

This was my issue.

Answer 3

Just change the format a little bit: androidx.gridlayout.widget.GridLayout newGrid= (androidx.gridlayout.widget.GridLayout) findViewById (R.id.yourGrid);

Answer 4

I got the same issue. I solved it by using the GridLayout from package android.support.v7.widget.GridLayout, since I was previously using the android.widget.GridLayout package which gave me the error.

Answer 5

I had the same issue and I just go to activity_main.xml and replaced

android.support.v7.widget.GridLayout

to this:

android.widget.GridLayout

Answer 6

Yes from your error log ,

android.support.v7.widget.GridLayout cannot be cast to android.widget.GridLayout
                      at devector.dom.gridtest.MainActivity.onCreate(MainActivity.java:21)

you can change your casting like this way to solve your problem

android.support.v7.widget.GridLayout grid = (android.support.v7.widget.GridLayout)findViewById(R.id.grid);

Answer 7

Caused by: java.lang.ClassCastException: android.support.v7.widget.GridLayout cannot be cast to android.widget.GridLayout at devector.dom.gridtest.MainActivity.onCreate(MainActivity.java:21)

=> From this line, it's clear that you must be importing and referring to android.widget.GridLayout where as you have taken android.support.v7.widget.GridLayout in XML layout. Use and refer either of any in both layout and class file.