如何在Android的編輯文本xml中設置水平線？

Question

我試圖在android記事本應用程序的editText中獲取水平線。一切都很好，但當我點擊添加註釋錯誤時出現錯誤。

在圖形佈局中，它顯示水平線條，但在模擬器上調用它時不起作用。請建議。

06-25 11:52:07.980: D/gralloc_goldfish(2235): Emulator without GPU emulation detected. 
06-25 11:52:11.178: D/AndroidRuntime(2235): Shutting down VM 
06-25 11:52:11.178: W/dalvikvm(2235): threadid=1: thread exiting with uncaught exception (group=0x409961f8) 
06-25 11:52:11.449: E/AndroidRuntime(2235): FATAL EXCEPTION: main 
06-25 11:52:11.449: E/AndroidRuntime(2235): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.android.sassypuma.todo.task/com.android.sassypuma.todo.task.Add_Task}: android.view.InflateException: Binary XML file line #3: Error inflating class com.android.sassypuma.todo.task.Add_Task.LinedEditText 
06-25 11:52:11.449: E/AndroidRuntime(2235):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1955) 
06-25 11:52:11.449: E/AndroidRuntime(2235):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1980) 
06-25 11:52:11.449: E/AndroidRuntime(2235):  at android.app.ActivityThread.access$600(ActivityThread.java:122) 
06-25 11:52:11.449: E/AndroidRuntime(2235):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1146) 
06-25 11:52:11.449: E/AndroidRuntime(2235):  at android.os.Handler.dispatchMessage(Handler.java:99) 
06-25 11:52:11.449: E/AndroidRuntime(2235):  at android.os.Looper.loop(Looper.java:137) 
06-25 11:52:11.449: E/AndroidRuntime(2235):  at android.app.ActivityThread.main(ActivityThread.java:4340) 
06-25 11:52:11.449: E/AndroidRuntime(2235):  at java.lang.reflect.Method.invokeNative(Native Method) 
06-25 11:52:11.449: E/AndroidRuntime(2235):  at java.lang.reflect.Method.invoke(Method.java:511) 
06-25 11:52:11.449: E/AndroidRuntime(2235):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784) 
06-25 11:52:11.449: E/AndroidRuntime(2235):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551) 
06-25 11:52:11.449: E/AndroidRuntime(2235):  at dalvik.system.NativeStart.main(Native Method) 
06-25 11:52:11.449: E/AndroidRuntime(2235): Caused by: android.view.InflateException: Binary XML file line #3: Error inflating class com.android.sassypuma.todo.task.Add_Task.LinedEditText 
06-25 11:52:11.449: E/AndroidRuntime(2235):  at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:691) 
06-25 11:52:11.449: E/AndroidRuntime(2235):  at android.view.LayoutInflater.inflate(LayoutInflater.java:466) 
06-25 11:52:11.449: E/AndroidRuntime(2235):  at android.view.LayoutInflater.inflate(LayoutInflater.java:396) 
06-25 11:52:11.449: E/AndroidRuntime(2235):  at android.view.LayoutInflater.inflate(LayoutInflater.java:352) 
06-25 11:52:11.449: E/AndroidRuntime(2235):  at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:251) 
06-25 11:52:11.449: E/AndroidRuntime(2235):  at android.app.Activity.setContentView(Activity.java:1835) 
06-25 11:52:11.449: E/AndroidRuntime(2235):  at com.android.sassypuma.todo.task.Add_Task.onCreate(Add_Task.java:19) 
06-25 11:52:11.449: E/AndroidRuntime(2235):  at android.app.Activity.performCreate(Activity.java:4465) 
06-25 11:52:11.449: E/AndroidRuntime(2235):  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1049) 
06-25 11:52:11.449: E/AndroidRuntime(2235):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1919) 
06-25 11:52:11.449: E/AndroidRuntime(2235):  ... 11 more 
06-25 11:52:11.449: E/AndroidRuntime(2235): Caused by: java.lang.ClassNotFoundException: com.android.sassypuma.todo.task.Add_Task.LinedEditText 
06-25 11:52:11.449: E/AndroidRuntime(2235):  at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:61) 
06-25 11:52:11.449: E/AndroidRuntime(2235):  at java.lang.ClassLoader.loadClass(ClassLoader.java:501) 
06-25 11:52:11.449: E/AndroidRuntime(2235):  at java.lang.ClassLoader.loadClass(ClassLoader.java:461) 
06-25 11:52:11.449: E/AndroidRuntime(2235):  at android.view.LayoutInflater.createView(LayoutInflater.java:552) 
06-25 11:52:11.449: E/AndroidRuntime(2235):  at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:680) 
06-25 11:52:11.449: E/AndroidRuntime(2235):  ... 20 more 

添加註釋活動：

public class Add_Task extends Activity{ 

private EditText description; 
@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.add_task); 
    description = (EditText)findViewById(R.id.note); 
} 

}

內襯編輯文本類：

class LinedEditText extends EditText { 
private Rect mRect; 
private Paint mPaint; 

// we need this constructor for LayoutInflater 
public LinedEditText(Context context, AttributeSet attrs, int defStyle) { 
    super(context, attrs, defStyle); 
    init(); 
} 

public void init(){ 
     mRect = new Rect(); 
     mPaint = new Paint(); 
     mPaint.setStyle(Paint.Style.FILL_AND_STROKE); 
     mPaint.setColor(0xFF668800); //SET YOUR OWN COLOR HERE 
} 
@Override 
protected void onDraw(Canvas canvas) { 
    //int count = getLineCount(); 

    int height = getHeight(); 
    int line_height = getLineHeight(); 

    int count = height/line_height; 

    if (getLineCount() > count) 
     count = getLineCount();//for long text with scrolling 

    Rect r = mRect; 
    Paint paint = mPaint; 
    int baseline = getLineBounds(0, r);//first line 

    for (int i = 0; i < count; i++) { 

     canvas.drawLine(r.left, baseline + 1, r.right, baseline + 1, paint); 
     baseline += getLineHeight();//next line 
    } 

    super.onDraw(canvas); 
} 

}

編輯：

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

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

<com.android.sassypuma.todo.task.LinedEditText 
xmlns:android="http://schemas.android.com/apk/res/android" 
android:id="@+id/note" 
android:layout_width="match_parent" 
android:layout_height="wrap_content" 
android:background="@android:color/transparent" 
android:padding="5dip" 
android:scrollbars="vertical" 
android:fadingEdge="vertical" 
android:gravity="top" 
android:textSize="22sp" 
android:lines="12" 
android:capitalize="sentences" /> 

</LinearLayout> 

Answer 1

只需在打開佈局的情況下關閉Eclipse。重新開始。這將刷新其與自定義類的鏈接。