Android--自定义带提示文本的EditText组件

效果图如下：

两个类，一个继承Activity的类，一个继承EditText的类，一个xml文件

继承Activity的类：

import android.app.Activity;
import android.os.Bundle;

public class EditTestActivity extends Activity {
	/** Called when the activity is first created. */
	@Override
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.edittest);
	}
}

继承EditText的类：

package com.mrzhu.edittest;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.util.AttributeSet;
import android.widget.EditText;

public class EditTextTest extends EditText {

	public EditTextTest(Context context) {
		super(context);
	}
	
	public EditTextTest(Context context, AttributeSet attrs, int defStyle) {
		super(context, attrs, defStyle);
	}

	public EditTextTest(Context context, AttributeSet attrs) {
		super(context, attrs);
	}

	@Override
	protected void onDraw(Canvas canvas) {
		Paint paint = new Paint();
		paint.setTextSize(20);
		paint.setColor(Color.GRAY);
		canvas.drawText("输入提示文本:", 10, getHeight() / 2 + 5, paint);
		super.onDraw(canvas);
	}
}

edittext.xml文件：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >
    <com.mrzhu.edittest.EditTextTest
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:paddingLeft="100dp"
        android:text="从此处输入文本"
        android:id="@+id/test"
        />
</LinearLayout>