java如何在安卓的MainActivity之外创建对话框
我想在我的安卓应用程序中插入一个提醒对话框。
当我按照教程将其添加到一个简单的项目中时,这很好,该项目只有一个MainActivity.java
、activity_main.xml
和一个layout
xml
然而,当我想在我的项目中插入代码时,我会遇到一些问题。 我的代码是:
安卓.app.AlertDialog alartDialog = new 安卓.app.AlertDialog.Builder(this)
.setTitle("Exit?")
.setMessage("Are you sure want to QUIT ?")
.setPositiveButton("yes", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialogInterface, int i) {
pmaControllerManager.OnExit();
}
})
.setNegativeButton("no", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int i) {
dialog.cancel();
}
})
.setNeutralButton("cancel", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialogInterface, int i) {
dialogInterface.cancel();
}
})
.show();
第一行的中有一个警告符号。 我该怎么修? p、 下面是我调用showDialog的函数(我在按钮[5]中调用它):
private void setbutton()
{
buttons[0]=(ImageButton)menu.findViewById(R.id.button0);
buttons[1]=(ImageButton)menu.findViewById(R.id.button1);
buttons[2]=(ImageButton)menu.findViewById(R.id.button2);
buttons[3]=(ImageButton)menu.findViewById(R.id.button3);
buttons[4]=(ImageButton)menu.findViewById(R.id.button4);
buttons[5]=(ImageButton)menu.findViewById(R.id.button5);
buttons[1].setBackgroundResource(R.drawable.screen);
buttons[2].setBackgroundResource(R.drawable.sketch);
buttons[3].setBackgroundResource(R.drawable.importdraw);
buttons[4].setBackgroundResource(R.drawable.setting);
buttons[5].setBackgroundResource(R.drawable.out);
center.setBackgroundResource(R.drawable.noticeicon_using);
/*center.setOnClickListener(new ImageButton.OnClickListener(){
@Override
public void onClick(View v) {
if(click)
{
closemenu();
//mode=false;
}
else
{
openmenu();
//mode=true;
}
click=!click;
}
});*/
center.setOnTouchListener(new View.OnTouchListener() {
boolean isMove=false;
int touchy,touchx,y;
@Override
public boolean onTouch(View view, MotionEvent motionEvent) {
int action=motionEvent.getAction();
if(action==MotionEvent.ACTION_DOWN)
{
y=params.y;
//Log.i("y:",String.valueOf(y));
touchy=(int)motionEvent.getRawY();
touchx=(int)motionEvent.getRawX();
}
else if(action==MotionEvent.ACTION_MOVE)
{
if(Math.abs(motionEvent.getRawX()-touchx)<30)
{
isMove=true;
params.gravity=Gravity.RIGHT;
params.y=y+(int)motionEvent.getRawY()-touchy;
wm.updateViewLayout(center,params);
wm.updateViewLayout(menu,params);
}
}
else if(action==MotionEvent.ACTION_UP)
{
if(!isMove)
{
if(click)
{
closemenu();
//mode=false;
}
else
{
openmenu();
//mode=true;
}
click=!click;
}
else
isMove=false;
}
return true;
}
});
buttons[1].setOnTouchListener(new View.OnTouchListener() {
@Override
public boolean onTouch(View v, MotionEvent event) {
if(event.getAction()==MotionEvent.ACTION_DOWN)
buttons[1].setBackgroundResource(R.drawable.screen_focus);
else if(event.getAction()==MotionEvent.ACTION_UP)
{
buttons[1].setBackgroundResource(R.drawable.screen);
pmaControllerManager.newTask("screen");
}
return true;
}
});
buttons[2].setOnTouchListener(new View.OnTouchListener() {
@Override
public boolean onTouch(View v, MotionEvent event) {
if(event.getAction()==MotionEvent.ACTION_DOWN)
buttons[2].setBackgroundResource(R.drawable.sketch_focus);
else if(event.getAction()==MotionEvent.ACTION_UP)
{
buttons[2].setBackgroundResource(R.drawable.sketch);
pmaControllerManager.newTask("sketch");
}
return true;
}
});
buttons[3].setOnTouchListener(new View.OnTouchListener() {
@Override
public boolean onTouch(View v, MotionEvent event) {
if(event.getAction()==MotionEvent.ACTION_DOWN)
buttons[3].setBackgroundResource(R.drawable.importdraw_focus);
else if(event.getAction()==MotionEvent.ACTION_UP)
{
buttons[3].setBackgroundResource(R.drawable.importdraw);
}
return true;
}
});
buttons[4].setOnTouchListener(new View.OnTouchListener() {
@Override
public boolean onTouch(View v, MotionEvent event) {
if(event.getAction()==MotionEvent.ACTION_DOWN)
buttons[4].setBackgroundResource(R.drawable.setting_focus);
else if(event.getAction()==MotionEvent.ACTION_UP)
{
buttons[4].setBackgroundResource(R.drawable.setting);
pmaControllerManager.Setting();
}
return true;
}
});
buttons[5].setOnTouchListener(new View.OnTouchListener() {
@Override
public boolean onTouch(View v, MotionEvent event) {
if(event.getAction()==MotionEvent.ACTION_DOWN)
buttons[5].setBackgroundResource(R.drawable.exit_focus);
else if(event.getAction()==MotionEvent.ACTION_UP)
{
buttons[5].setBackgroundResource(R.drawable.out);
shoaDialog(menuwindow.this);
pmaControllerManager.OnExit();
}
return true;
}
});
}
# 1 楼答案
用
MainActivity.this
或getApplicationContext()
替换this
如果您正在使用dialog,请查看以下内容:
活动:
ActivityName.this
对于片段:
getActivity()
对于适配器:
Context context;
还有,看看这个Difference between getContext() , getApplicationContext() , getBaseContext() and "this"
# 2 楼答案
将
this
替换为MainActivity.this
,如下所示: