onclickListener()用于动态的按钮



背景

我通过遵循dymmeh单个初始化解决方案格式的每个按钮的onclick listerer的解决方案,在for循环中动态创建按钮:

LinearLayout someLayout = (LinearLayout) findViewById(R.id.theRoom);
    for (int i = 0; i < neededButtons.length; i++){
        neededButtons[i] = new Button(this);
        neededButtons[i].setText(names[i]);
        neededButtons[i].setOnClickListener(this);
        LinearLayout.LayoutParams param = new LinearLayout.LayoutParams(
                LinearLayout.LayoutParams.FILL_PARENT,
                LinearLayout.LayoutParams.WRAP_CONTENT
        );
    }

此外,我通过在ActVity类中实现View.onclicklistener来制作一个onclick的听众。我的班级被定义为:

public class RecallActivity extends AppCompatActivity implements View.OnClickListener{
    ...
}

我成功地遵循了Pragnesh Ghota解决方案的其他步骤。但是...

问题

Pragnesh Ghota解决方案的第四步提到使用案例语句检查是否已单击了任何按钮。当已知按钮的量时,这起作用。但是,由于我遵循Dymmeh解决方案中列出的格式,因此我不知道在执行时间之前检查了多少按钮。

问题

如何在一个动态量的按钮中进行对控制流量语句?

创建每个按钮时只需为每个按钮创建一个新的OnClickListener。

LinearLayout someLayout = (LinearLayout) findViewById(R.id.theRoom);
for (int i = 0; i < neededButtons.length; i++){
    neededButtons[i] = new Button(this);
    neededButtons[i].setText(names[i]);
    neededButtons[i].setOnClickListener(new View.OnClickListener() {
                    @Override
                    public void onClick(View v) {
                        // add your click listener code here
                    }
                })
    LinearLayout.LayoutParams param = new LinearLayout.LayoutParams(
            LinearLayout.LayoutParams.FILL_PARENT,
            LinearLayout.LayoutParams.WRAP_CONTENT
    );
}

您可以为按钮设置id

LinearLayout someLayout = (LinearLayout) findViewById(R.id.theRoom);
for (int i = 0; i < neededButtons.length; i++){
    neededButtons[i] = new Button(this);
    neededButtons[i].setText(names[i]);
    neededButtons[i].setId(i);
    neededButtons[i].setOnClickListener(this);
    ...
    ); 
}

然后在OnClickListener中查找ID视图。例如:

public class RecallActivity extends AppCompatActivity implements View.OnClickListener{
  @overide
  public void onClick(View view){
     if(view.getId == 0){
        .....
   }
 }
}

最简单的解决方案是使用settag和gettag作为您的按钮。您可以将对象与settag和getTag一起使用。每当您创建一个按钮时,都为其设置标签:

for (int i = 0; i < neededButtons.length; i++){
    neededButtons[i] = new Button(this);
    neededButtons[i].setText(names[i]);
    neededButtons[i].setTag(names[i]);
    // or you can use the index as the tag with:
    // neededButtons[i].setTag(i);
    neededButtons[i].setOnClickListener(this);
}

然后,您通过检查标签为每个按钮做点事:

@Override
public void onClick(View v) {
    doSomething(v.getTag());
}
private void doSomething(Object tag) {
  // in case your tag is the index, than you can convert it to 
  // integer and use switch case
  int index = (int) tag;
  switch(index) {
    case 1:
      ...
      break;
    case 2:
      ...
      break;
    ...
  }
}

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