Android的按钮setAlpha

本文介绍了Android的按钮setAlpha的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述 有一组按钮，我想要得到的结果是：当我点击其中的一个，首先我将它们分为两部分：点击一个和其他人。我想设置不同的颜色或Alpha值不同的它们。现在我用 setAlpha ，但是当我从更改值 0〜255 ，它的工作原理，但是当我改变的值 255至0 ，它亘古不变的工作。我不知道为什么。也许以后我调用该方法 Button.setAlpha（），我需要调用其他方法？我的code： 公共类MainActivity延伸活动{ //按钮alpha值：减少值 公共静态INT BUTTON_ALPHA_MIN = 0; //按钮alpha值：实现价值最大化 公共静态INT BUTTON_ALPHA_MAX = 255; 私人的LinearLayout centerRegion; 私人的LinearLayout bottomRegion; 私人按钮btnCheckIn; 私人按钮btnReview; 私人按钮btnMyCircles; 私人按钮btnSettings; @覆盖 公共无效的onCreate（包savedInstanceState）{  super.onCreate（savedInstanceState）;  的setContentView（R.layout.main）;  //获取所有的部件  getAllWidgets（）;  //设置按钮点击响应函数  btnCheckIn.setOnClickListener（新OnClickListener（）{   公共无效的onClick（视图v）{    centerRegion.setBackgroundColor（android.graphics.Color.RED）;    。btnReview.getBackground（）setAlpha（BUTTON_ALPHA_MIN）;    。btnMyCircles.getBackground（）setAlpha（BUTTON_ALPHA_MIN）;    。btnSettings.getBackground（）setAlpha（BUTTON_ALPHA_MIN）;    。btnCheckIn.getBackground（）setAlpha（BUTTON_ALPHA_MAX）;   }  }）;  btnReview.setOnClickListener（新OnClickListener（）{   公共无效的onClick（视图v）{    centerRegion.setBackgroundColor（android.graphics.Color.BLUE）;    。btnCheckIn.getBackground（）setAlpha（BUTTON_ALPHA_MIN）;    。btnMyCircles.getBackground（）setAlpha（BUTTON_ALPHA_MIN）;    。btnSettings.getBackground（）setAlpha（BUTTON_ALPHA_MIN）;    。btnReview.getBackground（）setAlpha（BUTTON_ALPHA_MAX）;   }  }）;  btnMyCircles.setOnClickListener（新OnClickListener（）{   公共无效的onClick（视图v）{    centerRegion.setBackgroundColor（android.graphics.Color.YELLOW）;    。btnCheckIn.getBackground（）setAlpha（BUTTON_ALPHA_MAX）;    。btnReview.getBackground（）setAlpha（BUTTON_ALPHA_MAX）;    。btnSettings.getBackground（）setAlpha（BUTTON_ALPHA_MAX）;    。v.getBackground（）setAlpha（BUTTON_ALPHA_MIN）;   }  }）;  btnSettings.setOnClickListener（新OnClickListener（）{   公共无效的onClick（视图v）{    centerRegion.setBackgroundColor（android.graphics.Color.MAGENTA）;    。btnCheckIn.getBackground（）setAlpha（BUTTON_ALPHA_MAX）;    。btnReview.getBackground（）setAlpha（BUTTON_ALPHA_MAX）;    。btnMyCircles.getBackground（）setAlpha（BUTTON_ALPHA_MAX）;    。v.getBackground（）setAlpha（BUTTON_ALPHA_MIN）;   }  }）; } / **  *让所有的部件  * / 公共无效getAllWidgets（）{  this.centerRegion =（的LinearLayout）this.findViewById（R.id.center_region）;  this.bottomRegion =（的LinearLayout）this.findViewById（R.id.bottom_region）;  this.btnCheckIn =（按钮）this.findViewById（R.id.button_check_in）;  this.btnReview =（按钮）this.findViewById（R.id.button_review）;  this.btnMyCircles =（按钮）this.findViewById（R.id.button_my_circles）;  this.btnSettings =（按钮）this.findViewById（R.id.button_setting）; }} 解决方案 使用AlphaAnimation应该工作;验证我的设备上。 公共类测试扩展活动实现OnClickListener {    私人AlphaAnimation alphaDown;    私人AlphaAnimation alphaUp;    私人按钮B1;    私人按钮B2;    公共无效的onCreate（包savedInstanceState）{        super.onCreate（savedInstanceState）;        的setContentView（R.layout.main）;        的LinearLayout LL =（的LinearLayout）findViewById（R.id.linear_layout）;        B1 =新的按钮（这一点）;        b1.setText（按钮1）;        b1.setOnClickListener（本）;        ll.addView（B1）;        B2 =新的按钮（这一点）;        b2.setText（按钮2）;        b2.setOnClickListener（本）;        ll.addView（B2）;        alphaDown =新AlphaAnimation（1.0F，0.3f）;        alphaUp =新AlphaAnimation（0.3f，1.0F）;        alphaDown.setDuration（1000）;        alphaUp.setDuration（1000）;        alphaDown.setFillAfter（真正的）;        alphaUp.setFillAfter（真正的）;    }    公共无效的onClick（视图v）{        如果（V == B1）{            b1.startAnimation（alphaUp）;            b2.startAnimation（alphaDown）;        } 其他 {            b1.startAnimation（alphaDown）;            b2.startAnimation（alphaUp）;        }    }} 关键是呼吁 setFillAfter（真）使得α变化仍然存在。There are a set of buttons, I want to get the result:When I click one of them, first I divide them into two parts: the clicked one and the others. I'm trying to set different color or alpha value to different them.Now I use setAlpha, but when I change the value from 0 to 255, it works, but when I change the value from 255 to 0 , it doesnot work. I don't know why.Maybe after I invoke the methodButton.setAlpha(), I need invoke another method?my code:public class MainActivity extends Activity { // button alpha value: minimize value public static int BUTTON_ALPHA_MIN = 0; // button alpha value: maximize value public static int BUTTON_ALPHA_MAX = 255; private LinearLayout centerRegion; private LinearLayout bottomRegion; private Button btnCheckIn; private Button btnReview; private Button btnMyCircles; private Button btnSettings; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); // get all the widgets getAllWidgets(); // set buttons click response function btnCheckIn.setOnClickListener(new OnClickListener() { public void onClick(View v) { centerRegion.setBackgroundColor(android.graphics.Color.RED); btnReview.getBackground().setAlpha(BUTTON_ALPHA_MIN); btnMyCircles.getBackground().setAlpha(BUTTON_ALPHA_MIN); btnSettings.getBackground().setAlpha(BUTTON_ALPHA_MIN); btnCheckIn.getBackground().setAlpha(BUTTON_ALPHA_MAX); } }); btnReview.setOnClickListener(new OnClickListener() { public void onClick(View v) { centerRegion.setBackgroundColor(android.graphics.Color.BLUE); btnCheckIn.getBackground().setAlpha(BUTTON_ALPHA_MIN); btnMyCircles.getBackground().setAlpha(BUTTON_ALPHA_MIN); btnSettings.getBackground().setAlpha(BUTTON_ALPHA_MIN); btnReview.getBackground().setAlpha(BUTTON_ALPHA_MAX); } }); btnMyCircles.setOnClickListener(new OnClickListener() { public void onClick(View v) { centerRegion.setBackgroundColor(android.graphics.Color.YELLOW); btnCheckIn.getBackground().setAlpha(BUTTON_ALPHA_MAX); btnReview.getBackground().setAlpha(BUTTON_ALPHA_MAX); btnSettings.getBackground().setAlpha(BUTTON_ALPHA_MAX); v.getBackground().setAlpha(BUTTON_ALPHA_MIN); } }); btnSettings.setOnClickListener(new OnClickListener() { public void onClick(View v) { centerRegion.setBackgroundColor(android.graphics.Color.MAGENTA); btnCheckIn.getBackground().setAlpha(BUTTON_ALPHA_MAX); btnReview.getBackground().setAlpha(BUTTON_ALPHA_MAX); btnMyCircles.getBackground().setAlpha(BUTTON_ALPHA_MAX); v.getBackground().setAlpha(BUTTON_ALPHA_MIN); } }); } /** * get all the widgets */ public void getAllWidgets() { this.centerRegion = (LinearLayout) this.findViewById(R.id.center_region); this.bottomRegion = (LinearLayout) this.findViewById(R.id.bottom_region); this.btnCheckIn = (Button) this.findViewById(R.id.button_check_in); this.btnReview = (Button) this.findViewById(R.id.button_review); this.btnMyCircles = (Button) this.findViewById(R.id.button_my_circles); this.btnSettings = (Button) this.findViewById(R.id.button_setting); }} 解决方案 Using AlphaAnimation should work; verified on my device.public class Test extends Activity implements OnClickListener { private AlphaAnimation alphaDown; private AlphaAnimation alphaUp; private Button b1; private Button b2; public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); LinearLayout ll = (LinearLayout) findViewById(R.id.linear_layout); b1 = new Button(this); b1.setText("Button 1"); b1.setOnClickListener(this); ll.addView(b1); b2 = new Button(this); b2.setText("Button 2"); b2.setOnClickListener(this); ll.addView(b2); alphaDown = new AlphaAnimation(1.0f, 0.3f); alphaUp = new AlphaAnimation(0.3f, 1.0f); alphaDown.setDuration(1000); alphaUp.setDuration(1000); alphaDown.setFillAfter(true); alphaUp.setFillAfter(true); } public void onClick(View v) { if (v == b1) { b1.startAnimation(alphaUp); b2.startAnimation(alphaDown); } else { b1.startAnimation(alphaDown); b2.startAnimation(alphaUp); } }}The key is calling setFillAfter(true) so that the alpha change persists. 这篇关于Android的按钮setAlpha的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！