在Toast中实现文字滚动功能（也就是跑马灯效果）

闲话不多说了，直接上代码。

Main.java

package com.cn.lhq;import java.util.Timer;import java.util.TimerTask;import android.app.Activity;import android.os.Bundle;import android.view.Gravity;import android.view.LayoutInflater;import android.view.View;import android.view.ViewGroup;import android.view.View.OnClickListener;import android.widget.Button;import android.widget.Toast;public class Main extends Activity {@Overridepublic void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.main);btn1 = (Button) findViewById(R.id.ButtonTest);btn2 = (Button) findViewById(R.id.ButtonCancel);final Timer timer = new Timer();LayoutInflater inflater = getLayoutInflater();View layout = inflater.inflate(R.layout.toast,(ViewGroup) findViewById(R.id.llToast));AutoScrollTextView text = (AutoScrollTextView) layout.findViewById(R.id.TextViewNotice);text.init(getWindowManager());text.startScroll();final Toast myToast = new Toast(getApplicationContext());myToast.setGravity(Gravity.CENTER, 0, 0);myToast.setDuration(Toast.LENGTH_LONG);myToast.setView(layout);btn1.setOnClickListener(new OnClickListener() {@Overridepublic void onClick(View v) {flag = true;timer.schedule(new TimerTask(){@Overridepublic void run(){while (flag){myToast.show();}}}, 1);}});btn2.setOnClickListener(new OnClickListener() {@Overridepublic void onClick(View v) {flag = false;myToast.cancel();//timer.cancel();}});}private Button btn1;private Button btn2;private Boolean flag;} 

AutoScrollTextView.java

package com.cn.lhq;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.util.Log;import android.view.Display;import android.view.View;import android.view.WindowManager;import android.view.View.OnClickListener;import android.widget.TextView;// 单行文本跑马灯控件public class AutoScrollTextView extends TextView implements OnClickListener {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 = 80;temp_view_plus_text_length = 80;temp_view_plus_two_text_length = textLength;Log.i("test", temp_view_plus_text_length + "-----here-------");y = getTextSize() + getPaddingTop();}@Overridepublic Parcelable onSaveInstanceState() {Parcelable superState = super.onSaveInstanceState();SavedState ss = new SavedState(superState);ss.step = step;ss.isStarting = isStarting;return ss;}@Overridepublic 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);}@Overridepublic void writeToParcel(Parcel out, int flags) {super.writeToParcel(out, flags);out.writeBooleanArray(new boolean[] { isStarting });out.writeFloat(step);}public static final Parcelable.Creator<SavedState> CREATOR = new Parcelable.Creator<SavedState>() {public SavedState[] newArray(int size) {return new SavedState[size];}@Overridepublic 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();}@Overridepublic 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 = 80;invalidate();}@Overridepublic void onClick(View v) {if (isStarting)stopScroll();elsestartScroll();}}   

main.xml

<?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" android:addStatesFromChildren="true"><TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="@string/hello"/><Button android:text="显示" android:id="@+id/ButtonTest" android:layout_width="wrap_content" android:layout_height="wrap_content"/><Button android:text="取消" android:id="@+id/ButtonCancel" android:layout_width="wrap_content" android:layout_height="wrap_content"/></LinearLayout> 

toast.xml

<?xml version="1.0" encoding="utf-8"?><LinearLayoutxmlns:android="http://schemas.android.com/apk/res/android"android:layout_height="wrap_content" android:layout_width="wrap_content"android:background="#ffffffff" android:orientation="vertical"android:addStatesFromChildren="true"android:id="@+id/llToast" ><com.cn.lhq.AutoScrollTextView android:id="@+id/TextViewNotice"android:layout_height="wrap_content" android:layout_width="80px"android:text="在Toast中实现文字滚动功能" android:textColor="#0000FF" android:inputType="text"android:background="#FF0000" android:textSize="20px"/></LinearLayout>

 

效果图：