Question

我写了这个简单的代码，但我不知道为什么我的模拟器总是向我显示这个错误：“应用程序意外停止了android请再试一次”。我试图摆脱它，但没有成功帮助我，谢谢。

public class MainActivity extends Activity {

int counter;
Button add, sub;
TextView display;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    counter = 0;
    sub = (Button) findViewById(R.id.bSub);
    display = (Button) findViewById(R.id.tvDisplay);
    add = (Button) findViewById(R.id.bAdd);


    // *****onClick method****//
    add.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub
            counter = counter + 1;
            display.setText("Your Total is " + counter);
        }
    });

}
}



  //my xml//



<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical"
 tools:context=".MainActivity" >

<TextView
    android:id="@+id/tvDisplay"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:layout_gravity="center"
    android:gravity="center"
    android:text="@string/total"
    android:textSize="45sp" />

<Button
    android:id="@+id/bAdd"
    android:layout_width="250dp"
    android:layout_height="wrap_content"
    android:text="@string/add" />

<Button
    android:id="@+id/bSub"
    android:layout_width="250dp"
    android:layout_height="wrap_content"
    android:text="@string/sub" />

</LinearLayout>

我的清单

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.thenewbostonnn"
android:versionCode="1"
android:versionName="1.0" >

<uses-sdk
    android:minSdkVersion="8"
    android:targetSdkVersion="16" />

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

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

    </manifest>

Answer 1

使用

 display = (TextView) findViewById(R.id.tvDisplay);

而不是

 display = (Button) findViewById(R.id.tvDisplay);

目前，您正在向TextView投射Button

Answer 2

sub = (Button) findViewById(R.id.bSub);
display = (TextView ) findViewById(R.id.tvDisplay); // change button to TextView 
add = (Button) findViewById(R.id.bAdd);

“应用程序意外停止了android请再试一次”

2 个答案: