Cannot resolve method startActivity()

问题:

I'm new to the android development and having a bit of a problem changing activities. I am trying to change activities from within a method but I am getting the error cannot resolve method startActivity and on the parameter end the error Cannot resolve constructor 'Intent (...)'. I found a question here with the same sort of problem and tried to implement their replies into my program but no joy.

Here's the code:

public void open301(View view) {     startActivity(new Intent(CustomAdapter.this, ThreeZeroOne.class)); } 

before looking at the replies from the question linked above the code looked like this with the same errors:

public void open301(View view) {    Intent openThree = new Intent(this,ThreeZeroOne.class);     startActivity(openThree); } 

Complete code:

import android.content.Context; import android.view.LayoutInflater; import android.view.View; import android.view.View.OnClickListener; import android.view.ViewGroup; import android.widget.BaseAdapter; import android.widget.ImageView; import android.widget.TextView; import android.widget.Toast; import android.content.Intent;  public class CustomAdapter extends BaseAdapter {   String[] result;   Context context;   int[] imageId;    private static LayoutInflater inflater = null;    public CustomAdapter(selectGame SelectGame, String[] prgmNameList, int[] prgmImages) {     result = prgmNameList;     context = SelectGame;     this.imageId = prgmImages;     inflater = (LayoutInflater) context.getSystemService(Context.         LAYOUT_INFLATER_SERVICE);   }    @Override   public int getCount() {     return result.length;   }    @Override   public Object getItem(int position) {     return position;   }    @Override   public long getItemId(int position) {     return position;   }    public class Holder {     TextView tv;     ImageView img;   }    @Override   public View getView(final int position, View convertView, ViewGroup parent) {     Holder holder = new Holder();     View rowView;     rowView = inflater.inflate(R.layout.game_selection, null);     holder.tv = (TextView) rowView.findViewById(R.id.txt);     holder.img = (ImageView) rowView.findViewById(R.id.img);     holder.tv.setText(result[position]);     holder.img.setImageResource(imageId[position]);     rowView.setOnClickListener(new OnClickListener() {       @Override       public void onClick(View v) {         Toast.makeText(context, "Beginning game " + result[position], Toast.LENGTH_SHORT).show();        }     });     return rowView;   }    public void open301(View view) {     Intent openThree = new Intent(this,ThreeZeroOne.class);     startActivity(openThree);   } } 

回答1:

You should use the context of your adapter:

public void open301(View view) {   Intent openThree = new Intent(context,ThreeZeroOne.class);   context.startActivity(openThree); } 

回答2:

To start a new activity you will need a context to start from, and your current activity "BaseAdapter" is not a Context, luckly every view has a Context, so you can do like this:

public void open301(View view) {     Intent openThree = new Intent(view.getContext(), ThreeZeroOne.class);     view.getContext().startActivity(openThree); } 

回答3:

First you should get your Context:

private Context context;  public CustomAdapter(Context context) {     this.context = context; } 

And then:

context.startActivity(openThree); 

文章来源: Cannot resolve method startActivity()