如何启动一个活动并使用另一个类调用该类的方法

Question

我想同时从另一个类打开该类和该类的方法。当我点击按钮时，它会停止应用程序。帮帮我！类的固定装置“从中我想调用类的

方法和手段的

public void onClick(View arg0) { 
    // TODO Auto-generated method stub 

    int id = arg0.getId(); 
    FixtureDetails abc = new FixtureDetails(); 
    abc.xyz(id); 
    startActivity(new Intent(Fixtures.this, FixtureDetails.class)); 
} 

类和方法，其欲被打开

public class FixtureDetails extends Activity{ 

TextView tv; 
@Override 
protected void onCreate(Bundle savedInstanceState) { 
    // TODO Auto-generated method stub 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.fixturedetails); 
    tv = (TextView) findViewById(R.id.tv); 
} 

void xyz(int lmn) 
{ 
    switch(lmn) 
    { 
    case R.id.tvMatch1: 
     tv.setText("Hey there, wassup"); 
     break; 
    } 
} 
} 

Answer 1

由于Android处理活动类的生命周期不建议直接实例化，并且像你一样调用该方法，Android会重新创建类，无论如何会破坏您在其中更改的任何内容。

推荐的做法是使用Intent Extras将数据传递给Activity。

public void onClick(View arg0) { 
    // TODO Auto-generated method stub 

    int id = arg0.getId(); 
    Intent intent = new Intent(Fixtures.this, FixturesDetails.class); 
    intent.putExtra("id_key", id); // Set your ID as a Intent Extra 
    startActivity(intent); 
} 

FixtureDetails.class

public class FixtureDetails extends Activity{ 

    TextView tv; 
    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     // TODO Auto-generated method stub 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.fixturedetails); 
     tv = (TextView) findViewById(R.id.tv); 
     Intent intent = getIntent(); 
     if(intent != null && intent.getExtras() != null) { 
      xyz(intent.getIntExtra("id_key", -1)); // Run the method with the ID Value 
                // passed through the Intent Extra 
     } 
    } 

    void xyz(int lmn) { 
     switch(lmn) { 
      case R.id.tvMatch1: 
       tv.setText("Hey there, wassup"); 
       break; 
     } 
    } 
}