最近在开发一个应用，需要用到文本的跑马灯效果，图省事，在网上找，但老半天都找不到，后来自己写了一个，很简单，代码如下：

import android.content.Context;import android.graphics.Canvas;import android.graphics.Paint;import android.os.Parcel;import android.os.Parcelable;import android.util.AttributeSet;import android.view.Display;import android.view.View;import android.view.WindowManager;import android.view.View.OnClickListener;import android.widget.TextView;/** *  * TODO 单行文本跑马灯控件 * * @author tianlu * @version 1.0 * Create At : 2010-2-16 下午09:35:03 */public class AutoScrollTextView extends TextView implements OnClickListener {    public final static String TAG = AutoScrollTextView.class.getSimpleName();        private float textLength = 0f;//文本长度    private float viewWidth = 0f;    private float step = 0f;//文字的横坐标    private float y = 0f;//文字的纵坐标    private float temp_view_plus_text_length = 0.0f;//用于计算的临时变量    private float temp_view_plus_two_text_length = 0.0f;//用于计算的临时变量    public boolean isStarting = false;//是否开始滚动    private Paint paint = null;//绘图样式    private String text = "";//文本内容        public AutoScrollTextView(Context context) {        super(context);        initView();    }    public AutoScrollTextView(Context context, AttributeSet attrs) {        super(context, attrs);        initView();    }    public AutoScrollTextView(Context context, AttributeSet attrs, int defStyle) {        super(context, attrs, defStyle);        initView();    }        /**     * 初始化控件     */    private void initView()    {        setOnClickListener(this);    }        /**     * 文本初始化，每次更改文本内容或者文本效果等之后都需要重新初始化一下     */    public void init(WindowManager windowManager)    {        paint = getPaint();        text = getText().toString();        textLength = paint.measureText(text);        viewWidth = getWidth();        if(viewWidth == 0)        {            if(windowManager != null)            {                Display display = windowManager.getDefaultDisplay();                viewWidth = display.getWidth();            }        }        step = textLength;        temp_view_plus_text_length = viewWidth + textLength;        temp_view_plus_two_text_length = viewWidth + textLength * 2;        y = getTextSize() + getPaddingTop();    }        @Override    public Parcelable onSaveInstanceState()    {        Parcelable superState = super.onSaveInstanceState();        SavedState ss = new SavedState(superState);                ss.step = step;        ss.isStarting = isStarting;                return ss;            }        @Override    public void onRestoreInstanceState(Parcelable state)    {        if (!(state instanceof SavedState)) {            super.onRestoreInstanceState(state);            return;        }        SavedState ss = (SavedState)state;        super.onRestoreInstanceState(ss.getSuperState());                step = ss.step;        isStarting = ss.isStarting;    }        public static class SavedState extends BaseSavedState {        public boolean isStarting = false;        public float step = 0.0f;        SavedState(Parcelable superState) {            super(superState);        }        @Override        public void writeToParcel(Parcel out, int flags) {            super.writeToParcel(out, flags);            out.writeBooleanArray(new boolean[]{isStarting});            out.writeFloat(step);        }        public static final Parcelable.Creator
     
       CREATOR                = new Parcelable.Creator
      
       () {                        public SavedState[] newArray(int size) {                return new SavedState[size];            }            @Override            public SavedState createFromParcel(Parcel in) {                return new SavedState(in);            }        };        private SavedState(Parcel in) {            super(in);            boolean[] b = null;            in.readBooleanArray(b);            if(b != null && b.length > 0)                isStarting = b[0];            step = in.readFloat();        }    }    /**     * 开始滚动     */    public void startScroll()    {        isStarting = true;        invalidate();    }        /**     * 停止滚动     */    public void stopScroll()    {        isStarting = false;        invalidate();    }        @Override    public void onDraw(Canvas canvas) {        canvas.drawText(text, temp_view_plus_text_length - step, y, paint);        if(!isStarting)        {            return;        }        step += 0.5;        if(step > temp_view_plus_two_text_length)            step = textLength;        invalidate();    }    @Override    public void onClick(View v) {        if(isStarting)            stopScroll();        else            startScroll();            }}
      
     

实现了宽度的判断，文本自动滚动及开始和停止滚动等功能。

在UI xml中的配置如下：

在Activity中的使用方法如下：

//启动公告滚动条        autoScrollTextView = (AutoScrollTextView)findViewById(R.id.TextViewNotice);        autoScrollTextView.init(getWindowManager());        autoScrollTextView.startScroll();

如果想改变跑马灯的文字内容或者文字效果，则在调用完setText方法之后，需要再调用一下init(WindowManager windowManager)方法，重新进行初始化和相关参数的计算。

http://www.blogjava.net/TiGERTiAN/archive/2010/02/13/312840.html