Question

我是android的新手

我有2个文件login.java和depan.java 当我点击按钮登录它是正常的文件depan.java加载成功

当我输入此代码时，

似乎错误开始

          buttonuser = (ImageButton) findViewById(R.id.BtnUser);

depan.class无法加载，应用程序崩溃。

depan.class

public class Depan extends  Activity{
ImageButton buttonuser, buttonvlan;
    @Override
    public void onCreate(Bundle wibi) {
        // TODO Auto-generated method stub
        super.onCreate(wibi);
        setContentView (R.layout.depan);

        buttonuser = (ImageButton) findViewById(R.id.BtnUser);

depan.xml

<?xml version="1.0" encoding="utf-8"?>



<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/LinearLayout1"
    android:layout_width="fill_parent"
    android:layout_height="match_parent"
    android:background="@drawable/background"
    android:gravity="center_horizontal|center_vertical"
    android:orientation="vertical" >



    <ImageView
        android:id="@+id/BtnUser"
        android:layout_width="150dp"
        android:layout_height="100dp"
        android:scaleType="fitXY"
        android:src="@drawable/manajemenuser" />


    <ImageView
        android:id="@+id/BtnVlan"
        android:layout_width="150dp"
        android:layout_height="100dp"
        android:scaleType="fitXY"
        android:src="@drawable/manajemenvlan" />




</LinearLayout>

清单

    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="15" />

    <application
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name=".MainActivity"
            android:label="@string/title_activity_main" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>


         <activity
            android:name=".login"
            android:label="@string/title_activity_main" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>


         <activity
            android:name=".Depan"
            android:label="@string/title_activity_main" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

         <activity
            android:name=".user"
            android:label="@string/title_activity_main" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

         <activity
            android:name=".vlan"
            android:label="@string/title_activity_main" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>


    </application>
    <uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
</manifest>

Answer 1

   buttonuser = (**ImageButton**) findViewById(R.id.BtnUser);

<**ImageView**
        android:id="@+id/**BtnUser**"
        android:layout_width="150dp"
        android:layout_height="100dp"
        android:scaleType="fitXY"
        android:src="@drawable/manajemenuser" />

ImageView BtnUser ....你为什么把它投射到ImageButton ???

Answer 2

将xml中的ImageView更改为ImageButton

加载下一页时android崩溃

2 个答案: