需要做一个弹出窗或者遮罩层，我们一般有以下几种思路。
1、AlertDialog对话框
2、PopupWindow弹出窗
3、WindowManager动态添加View到当前页面
4、打开另外一个Activity
下面分别给出这几种方法的实现栗子。
一、AlertDialog
适合需要用户做出选择，或者确认的弹出小窗
AlertDialog.Builder dialog = new AlertDialog.Builder(TestActivity.this);
//自定义
//dialog.setView(LayoutInflater.from(TestActivity.this).inflate(R.layout.layout_dialog, null));
dialog.setTitle("Do you like Android?");
dialog.setNegativeButton("No", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
dialog.dismiss();
}
});
dialog.setPositiveButton("Yes", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
Toast.makeText(TestActivity.this, "you choose yes", Toast.LENGTH_SHORT).show();
dialog.dismiss();
}
});
dialog.show();
二、PopupWindow
适合做遮罩页面
final PopupWindow popup = new PopupWindow(TestActivity.this);
View popView = LayoutInflater.from(TestActivity.this).inflate(R.layout.popuptest, null);
popup.setContentView(popView);
popup.setFocusable(true);
DisplayMetrics metric = new DisplayMetrics();
getWindowManager().getDefaultDisplay().getMetrics(metric);
int width = metric.widthPixels; // 屏幕宽度（像素）
int height = metric.heightPixels; // 屏幕高度（像素）
popup.setWidth(Integer.parseInt(new DecimalFormat("0").format(width * 0.8)));
popup.setHeight(Integer.parseInt(new DecimalFormat("0").format(height * 0.8)));
popup.showAtLocation(TestActivity.this.findViewById(R.id.btnDialog), Gravity.CENTER, 0, 0);
popView.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
popup.dismiss();
}
});
三、WindowManager
适合弹出带动画的小窗
//WindowManager
View vRating;
try {
vRating = LayoutInflater.from(TestActivity.this).inflate(R.layout.layout_rating, null);
} catch (Exception e) {
return;
} catch (OutOfMemoryError e) {
return;
}
//设置页面属性
WindowManager.LayoutParams layoutParams = new WindowManager.LayoutParams();
layoutParams.height = WindowManager.LayoutParams.MATCH_PARENT;
layoutParams.width = WindowManager.LayoutParams.MATCH_PARENT;
layoutParams.flags = WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE | WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON | WindowManager.LayoutParams.FLAG_LAYOUT_IN_SCREEN
| WindowManager.LayoutParams.FLAG_LAYOUT_NO_LIMITS;
// layoutParams.flags = WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON | WindowManager.LayoutParams.FLAG_LAYOUT_IN_SCREEN
// | WindowManager.LayoutParams.FLAG_LAYOUT_NO_LIMITS| WindowManager.LayoutParams.FLAG_ALT_FOCUSABLE_IM;
layoutParams.format = PixelFormat.TRANSLUCENT;
// layoutParams.type = WindowManager.LayoutParams.TYPE_TOAST;
layoutParams.type = WindowManager.LayoutParams.TYPE_PHONE;
layoutParams.x = 0;
layoutParams.y = 0;
final WindowManager wm = (WindowManager) TestActivity.this.getApplicationContext().getSystemService(Context.WINDOW_SERVICE);
wm.addView(vRating, layoutParams);
final View negativeButton = vRating.findViewById(R.id.negativeButton);
negativeButton.setOnClickListener(new OnClickListener() {
//to do
});
}
final View positiveButton = vRating.findViewById(R.id.positiveButton);
positiveButton.setOnClickListener(new OnClickListener() {
//to do
});
四、Activity
适合做透明遮罩页面，实现原理是跳转到另外一个Activity A后，再延时跳出一个Activity B，这样后面的B就会遮住前面的A。
//Activity
final Handler handler = new Handler();
Runnable runnable = new Runnable() {
@Override
public void run() {
Intent intent = new Intent(TestActivity.this, DialogActivity.class);
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
TestActivity.this.startActivity(intent);
}
};
handler.postDelayed(runnable, 500L);